Picture of the Week

13 October 2014: The brightly glowing plumes seen in this image are reminiscent of an underwater scene, with turquoise-tinted currents and nebulous strands reaching out into the surroundings. However, this is no ocean. This image actually shows part of the Large Magellanic Cloud (LMC), a small nearby galaxy that orbits our galaxy, the Milky Way, and appears as a blurred blob in our skies. The NASA/ESA Hubble Space Telescope has peeked many times into this galaxy, releasing stunning images of the whirling clouds of gas and sparkling stars (opo9944a, heic1301, potw1408a). This image shows part of the Tarantula Nebula's outskirts. This famously beautiful nebula, located within the LMC, is a frequent target for Hubble (heic1206, heic1402). In most images of the LMC the colour is completely different to that seen here. This is because, in this new image, a different set of filters was used. The customary R filter, which selects the red …

6 October 2014: This magnificent new image taken with the NASA/ESA Hubble Space Telescope shows the edge-on spiral galaxy NGC 4206, located about 70 million light-years away from Earth in the constellation of Virgo. Captured here are vast streaks of dust, some of which are obscuring the central bulge, which can just be made out in the centre of the galaxy. Towards the edges of the galaxy, the scattered clumps, which appear blue in this image, mark areas where stars are being born. The bulge, on the other hand, is composed mostly of much older, redder stars, and very little star formation takes place. NGC 4206 was imaged as part of a Hubble snapshot survey of nearby edge-on spiral galaxies to measure the effect that the material between the stars — known as the interstellar medium — has on light as it travels through it. Using its Advanced Camera for Surveys, Hubble can …

29 September 2014: In this new Hubble image, the strikingly luminous star AG Carinae — otherwise known as HD 94910 — takes centre stage. Found within the constellation of Carina in the southern sky, AG Carinae lies 20 000 light-years away, nestled in the Milky Way. AG Carinae is classified as a Luminous Blue Variable. These rare objects are massive evolved stars that will one day become Wolf-Rayet Stars — a class of stars that are tens of thousands to several million times as luminous as the Sun. They have evolved from main sequence stars that were twenty times the mass of the Sun. Stars like AG Carinae lose their mass at a phenomenal rate. This loss of mass is due to powerful stellar winds with speeds of up to 7 million km/hour. These powerful winds are also responsible for the shroud of material visible in this image. The winds exert enormous pressure on the …

22 September 2014: This new image from the NASA/ESA Hubble Space Telescope shows NGC 7793, a spiral galaxy in the constellation of Sculptor some 13 million light-years away from Earth. NGC 7793 is one of the brightest galaxies in the Sculptor Group, and one of the closest groups of galaxies to the Local Group — the group of galaxies containing our galaxy, the Milky Way and the Magellanic Clouds. The image shows NGC 7793’s spiral arms and small central bulge. Unlike some other spirals, NGC 7793 doesn’t have a very pronounced spiral structure, and its shape is further muddled by the mottled pattern of dark dust that stretches across the frame. The occasional burst of bright pink can be seen in the galaxy, highlighting stellar nurseries containing newly-forming baby stars. Although it may look serene and beautiful from our perspective, this galaxy is actually a very dramatic and violent place. Astronomers have discovered …

15 September 2014: This picture, taken by the NASA/ESA Hubble Space Telescope’s Wide Field Planetary Camera 2 (WFPC2), shows a galaxy known as NGC 6872 in the constellation of Pavo (The Peacock). Its unusual shape is caused by its interactions with the smaller galaxy that can be seen just above NGC 6872, called IC 4970. They both lie roughly 300 million light-years away from Earth. From tip to tip, NGC 6872 measures over 500 000 light-years across, making it the second largest spiral galaxy discovered to date. In terms of size it is beaten only by NGC 262, a galaxy that measures a mind-boggling 1.3 million light-years in diameter! To put that into perspective, our own galaxy, the Milky Way, measures between 100 000 and 120 000 light-years across, making NGC 6872 about five times its size. The upper left spiral arm of NGC 6872 is visibly distorted and is populated by star-forming …

8 September 2014: Far beyond the stars in the constellation of Leo (The Lion) is irregular galaxy IC 559. IC 559 is not your everyday galaxy. With its irregular shape and bright blue spattering of stars, it is a fascinating galactic anomaly. It may look like sparse cloud, but it is in fact full of gas and dust which is spawning new stars. Discovered in 1893, IC 559 lacks the symmetrical spiral appearance of some of its galactic peers and not does not conform to a regular shape. It is actually classified as a “type Sm” galaxy — an irregular galaxy with some evidence for a spiral structure. Irregular galaxies make up about a quarter of all known galaxies and do not fall into any of the regular classes of the Hubble sequence. Most of these uniquely shaped galaxies were not always so — IC 559 may have once been a conventional spiral …

1 September 2014: This new NASA/ESA Hubble Space Telescope image shows a beautiful spiral galaxy known as PGC 54493, located in the constellation of Serpens (The Serpent). This galaxy is part of a galaxy cluster that has been studied by astronomers exploring an intriguing phenomenon known as weak gravitational lensing. This effect, caused by the uneven distribution of matter (including dark matter) throughout the Universe, has been explored via surveys such as the Hubble Medium Deep Survey. Dark matter is one of the great mysteries in cosmology. It behaves very differently from ordinary matter as it does not emit or absorb light or other forms of electromagnetic energy — hence the term "dark". Even though we cannot observe dark matter directly, we know it exists. One prominent piece of evidence for the existence of this mysterious matter is known as the "galaxy rotation problem". Galaxies rotate at such speeds and in such a …

25 August 2014: This new NASA/ESA Hubble Space Telescope image shows a variety of intriguing cosmic phenomena. Surrounded by bright stars, towards the upper middle of the frame we see a small young stellar object (YSO) known as SSTC2D J033038.2+303212. Located in the constellation of Perseus, this star is in the early stages of its life and is still forming into a fully grown star. In this view from Hubble’s Advanced Camera for Surveys (ACS) it appears to have a murky chimney of material emanating outwards and downwards, framed by bright bursts of gas flowing from the star itself. This fledgling star is actually surrounded by a bright disc of material swirling around it as it forms — a disc that we see edge-on from our perspective. However, this small bright speck is dwarfed by its cosmic neighbour towards the bottom of the frame, a clump of bright, wispy gas swirling around as …

18 August 2014: This stunning new image from the NASA/ESA Hubble Space Telescope shows part of the sky in the constellation of Canes Venatici (The Hunting Dogs). Although this region of the sky is not home to any stellar heavyweights, being mostly filled with stars of average brightness, it does contain five Messier objects and numerous intriguing galaxies — including NGC 5195, a small barred spiral galaxy considered to be one of the most beautiful galaxies visible, and its nearby interacting partner the Whirlpool Galaxy (heic0506a). The quirky Sunflower Galaxy is another notable galaxy in this constellation, and is one of the largest and brightest edge-on galaxies in our skies. Joining this host of characters is spiral galaxy NGC 4244, nicknamed the Silver Needle Galaxy, shown here in a new image from Hubble. This galaxy spans some 65 000 light-years and lies around 13.5 million light-years away. It appears as a wafer-thin streak …

11 August 2014: This new NASA/ESA Hubble Space Telescope image shows a whole host of colourful and differently shaped galaxies; some bright and nearby, some fuzzy, and some so far from us they appear as small specks in the background sky. The most prominent characters are the two galaxies on the left — 2MASX J16133219+5103436 at the bottom, and its blue-tinted companion SDSS J161330.18+510335 at the top. The latter is slightly closer to us than its partner, but the two are still near enough to one another to interact. Together, the two make up a galactic pair named Zw I 136. Both galaxies in this pair have disturbed shapes and extended soft halos. They don’t seem to conform to our view of a “typical” galaxy — unlike the third bright object in this frame, a side-on spiral seen towards the right of the image. Astronomers classify galaxies according to their appearance and their …

4 August 2014: This new NASA/ESA Hubble Space Telescope image shows the globular cluster IC 4499. Globular clusters are big balls of old stars that orbit around their host galaxy. It has long been believed that all the stars within a globular cluster form at the about same time, a property which can be used to determine the cluster's age. For more massive globulars however, detailed observations have shown that this is not entirely true — there is evidence that they instead consist of multiple populations of stars born at different times. One of the driving forces behind this behaviour is thought to be gravity: more massive globulars manage to grab more gas and dust, which can then be transformed into new stars. IC 4499 is a somewhat special case. Its mass lies somewhere between low-mass globulars, which show a single generation build-up, and the more complex and massive globulars which can contain …

28 July 2014: From objects as small as Newton's apple to those as large as a galaxy, no physical body is free from the stern bonds of gravity, as evidenced in this stunning picture captured by the Wide Field Camera 3 and Advanced Camera for Surveys onboard the NASA/ESA Hubble Space Telescope. Here we see two spiral galaxies engaged in a cosmic tug-of-war — but in this contest, there will be no winner. The structures of both objects are slowly distorted to resemble new forms, and in some cases, merge together to form new, super galaxies. This particular fate is similar to that of the Milky Way Galaxy, when it will ultimately merge with our closest galactic partner, the Andromeda Galaxy. There is no need to panic however, as this process takes several hundreds of millions of years. Not all interacting galaxies result in mergers though. The merger is dependent on the mass …

21 July 2014: The thin, glowing streak slicing across this image cuts a lonely figure, with only a few foreground stars and galaxies in the distant background for company. However, this is all a case of perspective; lying out of frame is another nearby spiral. Together, these two galaxies make up a pair, moving through space together and keeping one another company. The subject of this Hubble image is called NGC 3501, with NGC 3507 as its out-of-frame companion. The two galaxies look very different — another example of the importance of perspective. NGC 3501 appears edge-on, giving it an elongated and very narrow appearance. Its partner, however, looks very different indeed, appearing face-on and giving us a fantastic view of its barred swirling arms. While similar arms may not be visible in this image of NGC 3501, this galaxy is also a spiral — although it is somewhat different from its companion. …

14 July 2014: This image shows NGC 121, a globular cluster in the constellation of Tucana (The Toucan). Globular clusters are big balls of old stars that orbit the centres of their galaxies like satellites — the Milky Way, for example, has around 150. NGC 121 belongs to one of our neighbouring galaxies, the Small Magellanic Cloud (SMC). It was discovered in 1835 by English astronomer John Herschel, and in recent years it has been studied in detail by astronomers wishing to learn more about how stars form and evolve. Stars do not live forever — they develop differently depending on their original mass. In many clusters, all the stars seem to have formed at the same time, although in others we see distinct populations of stars that are different ages. By studying old stellar populations in globular clusters, astronomers can effectively use them as tracers for the stellar population of their host …

7 July 2014: This view, captured by the NASA/ESA Hubble Space Telescope, shows a nearby spiral galaxy known as NGC 1433. At about 32 million light-years from Earth, it is a type of very active galaxy known as a Seyfert galaxy — a classification that accounts for 10% of all galaxies. They have very bright, luminous centres comparable to that of our galaxy, the Milky Way. Galaxy cores are of great interest to astronomers. The centres of most, if not all, galaxies are thought to contain a supermassive black hole, surrounded by a disc of infalling material. NGC 1433 is being studied as part of a survey of 50 nearby galaxies known as the Legacy ExtraGalactic UV Survey (LEGUS). Ultraviolet radiation is observed from galaxies, mainly tracing the most recently formed stars. In Seyfert galaxies, ultraviolet light is also thought to emanate from the accretion discs around their central black holes. Studying these …

30 June 2014: Discovered by astronomer William Herschel in the late 1700s, NGC 201 is a barred spiral galaxy similar to our own galaxy, the Milky Way. It lies 200 million light-years from Earth in the constellation of Cetus (The Sea Monster), and is invisible to the naked eye. This new NASA/ESA Hubble Space Telescope image of NGC 201 shows the galaxy in striking detail, capturing the bright centre and the barred spiral arms — arms that do not start directly from the galactic centre, but instead seem to be offset and stem from a "bar" of stars cutting through the middle of the galaxy. Along with three of its closest galactic neighbours (outside the frame), NGC 201 belongs to a group known as the HCG 7 compact galactic group. Hickson Compact Groups (HCG) are relatively small and isolated systems containing a handful of bright, compact galaxies that lie close to one another. …

23 June 2014: This bright spiral galaxy is known as NGC 2441, located in the northern constellation of Camelopardalis (The Giraffe). However, NGC 2441 is not the only subject of this new Hubble image; the galaxy contains an intriguing supernova named SN1995E, visible as a small dot at the approximate centre of this image. For a labelled view, see potw1425b. Supernova SN1995E, discovered in 1995 as its name suggests is a type Ia supernova. This kind of supernova is found in binary systems, where one star — a white dwarf — drags matter from its orbiting companion until it becomes unstable and explodes violently. White dwarf stars all become unbalanced once they reach the same mass, meaning that they all form supernovae with the same intrinsic brightness. Because of this, they are used as standard candles to measure distances in the Universe. But SN1995E may be useful in another way. More recent observations …

16 June 2014: The subject of this new Hubble image is NGC 5474, a dwarf galaxy located 21 million light-years away in the constellation of Ursa Major (The Great Bear). This beautiful image was taken with Hubble's Advanced Camera for Surveys (ACS). The term "dwarf galaxy" may sound diminutive, but don't let that fool you — NGC 5474 contains several billion stars! However, when compared to the Milky Way with its hundreds of billions of stars, NGC 5474 does indeed seem relatively small. NGC 5474 itself is part of the Messier 101 Group. The brightest galaxy within this group is the well-known spiral Pinwheel Galaxy (also known as Messier 101, heic0602). This galaxy's prominent, well-defined arms classify it as a "grand design galaxy", along with other spirals Messier 81 (heic0710) and Messier 74 (heic0719). Also within this group are Messier 101's galactic neighbours. It is possible that gravitational interactions with these companion galaxies …

9 June 2014: Taking centre stage in this new NASA/ESA Hubble Space Telescope image is a galaxy known as NGC 3081, set against an assortment of glittering galaxies in the distance. Located in the constellation of Hydra (The Sea Serpent), NGC 3081 is located over 86 million light-years from us. It is known as a type II Seyfert galaxy, characterised by its dazzling nucleus. NGC 3081 is seen here nearly face-on. Compared to other spiral galaxies, it looks a little different. The galaxy's barred spiral centre is surrounded by a bright loop known as a resonance ring. This ring is full of bright clusters and bursts of new star formation, and frames the supermassive black hole thought to be lurking within NGC 3081 — which glows brightly as it hungrily gobbles up infalling material. These rings form in particular locations known as resonances, where gravitational effects throughout a galaxy cause gas to pile …

2 June 2014: This new Hubble image shows NGC 1566, a beautiful galaxy located approximately 40 million light-years away in the constellation of Dorado (The Dolphinfish). NGC 1566 is an intermediate spiral galaxy, meaning that while it does not have a well defined bar-shaped region of stars at its centre — like barred spirals — it is not quite an unbarred spiral either (heic9902o). The small but extremely bright nucleus of NGC 1566 is clearly visible in this image, a telltale sign of its membership of the Seyfert class of galaxies. The centres of such galaxies are very active and luminous, emitting strong bursts of radiation and potentially harbouring supermassive black holes that are many millions of times the mass of the Sun. NGC 1566 is not just any Seyfert galaxy; it is the second brightest Seyfert galaxy known. It is also the brightest and most dominant member of the Dorado Group, a …

26 May 2014: This new Hubble image shows IRAS 14568-6304, a young star that is cloaked in a haze of golden gas and dust. It appears to be embedded within an intriguing swoosh of dark sky, which curves through the image and obscures the sky behind. This dark region is known as the Circinus molecular cloud. This cloud has a mass around 250 000 times that of the Sun, and it is filled with gas, dust and young stars. Within this cloud lie two prominent and enormous regions known colloquially to astronomers as Circinus-West and Circinus-East. Each of these clumps has a mass of around 5000 times that of the Sun, making them the most prominent star-forming sites in the Circinus cloud. The clumps are associated with a number of young stellar objects, and IRAS 14568-6304, featured here under a blurry fog of gas within Circinus-West, is one of them. IRAS 14568-6304 is …

19 May 2014: Astronomers using the NASA/ESA Hubble Space Telescope have captured new images of the dancing auroral lights at Saturn’s north pole. Taken from Hubble’s perspective in orbit around the Earth, these images provide a detailed look at Saturn’s stormy aurorae — revealing previously unseen dynamics in the choreography of the auroral glow. The cause of the changing patterns in Saturn's aurorae is an ongoing mystery in planetary science. These ultraviolet images, taken by Hubble’s super-sensitive Advanced Camera for Surveys, add new insight by capturing moments when Saturn’s magnetic field is affected by bursts of particles streaming out from the Sun. Saturn has a long, comet-like magnetic tail known as a magnetotail — as do Mercury, Jupiter, Uranus, Neptune and Earth [1]. This magnetotail is present around planets that have a magnetic field, caused by a rotating core of magnetic elements. It appears that when bursts of particles from the Sun hit …

12 May 2014: This image shows galaxy NGC 4485 in the constellation of Canes Venatici (The Hunting Dogs). The galaxy is irregular in shape, but it hasn’t always been so. Part of NGC 4485 has been dragged towards a second galaxy, named NGC 4490 — which lies out of frame to the bottom right of this image. Between them, these two galaxies make up a galaxy pair called Arp 269. Their interactions have warped them both, turning them from spiral galaxies into irregular ones. NGC 4485 is the smaller galaxy in this pair, which provides a fantastic real-world example for astronomers to compare to their computer models of galactic collisions. The most intense interaction between these two galaxies is all but over; they have made their closest approach and are now separating. The trail of bright stars and knotty orange clumps that we see here extending out from NGC 4485 is all that …

5 May 2014: This bundle of bright stars and dark dust is a dwarf spiral galaxy known as NGC 4605, located around 16 million light-years away in the constellation of Ursa Major (The Great Bear). This galaxy’s spiral structure is not obvious from this image, but NGC 4605 is classified as an SBc type galaxy — meaning that it has sprawling, loosely wound arms and a bright bar of stars cutting through its centre. NGC 4605 is a member of the Messier 81 group of galaxies, a gathering of bright galaxies including its namesake Messier 81 (heic0710), and the well-known Messier 82 (heic0604a). Galaxy groups like this usually contain around 50 galaxies, all loosely bound together by gravity. This group is famous for its unusual members, many of which formed from collisions between galaxies. With its somewhat unusual form, NGC 4605 fits in well with the family of perturbed galaxies in the M81 …

28 April 2014: This new Hubble picture is the sharpest ever image of the core of spiral galaxy Messier 61 and the central part of the galaxy is shown in striking detail. The image is comprised of 2003 and 2004 data from the now decommissioned High Resolution Channel (HRC) of Hubble's Advanced Camera for Surveys. Also known as NGC 4303, this galaxy is roughly 100 000 light-years across, comparable in size to our galaxy, the Milky Way. Both Messier 61 and our home galaxy belong to a group of galaxies known as the Virgo Supercluster in the constellation of Virgo (The Virgin) — a group of galaxy clusters containing up to 2000 spiral and elliptical galaxies in total. Messier 61 is a type of galaxy known as a starburst galaxy. Starburst galaxies experience an incredibly high rate of star formation, hungrily using up their reservoir of gas in a very short period of time (in astronomical …

21 April 2014: This sparkling jumble is Messier 5 — a globular cluster consisting of hundreds of thousands of stars bound together by their collective gravity. But Messier 5 is no normal globular cluster. At 13 billion years old it is incredibly old, dating back to close to the beginning of the Universe, which is some 13.8 billion years of age. It is also one of the biggest clusters known, and at only 24 500 light-years away, it is no wonder that Messier 5 is a popular site for astronomers to train their telescopes on. Messier 5 also presents a puzzle. Stars in globular clusters grow old and wise together. So Messier 5 should, by now, consist of old, low-mass red giants and other ancient stars. But it is actually teeming with young blue stars known as blue stragglers. These incongruous stars spring to life when stars collide, or rip material from one …

14 April 2014: Shown here is a spiral galaxy known as NGC 3455, which lies some 65 million light-years away from us in the constellation of Leo (The Lion). Galaxies are classified into different types according to their structure and appearance. This classification system is known as the Hubble Sequence, named after its creator Edwin Hubble. In this sequence, NGC 3455 is known as a type SB galaxy — a barred spiral. Barred spiral galaxies account for approximately two thirds of all spirals. Galaxies of this type appear to have a bar of stars slicing through the bulge of stars at their centre. The SB classification is further sub-divided by the appearance of a galaxy's pinwheeling spiral arms; SBa types have more tightly wound arms, whereas SBc types have looser ones. SBb types, such as NGC 3455, lie in between. NGC 3455 is part of a pair of galaxies — its partner, NGC …

7 April 2014: When astronomical objects are named, astronomers like to pick out notable features for inspiration — for example, the Whirlpool Galaxy with its pinwheeling arms, or the Needle Galaxy, which appears as a long, thin streak of silver across the sky. This image shows a galaxy cluster known as El Gordo, or “the fat one”, a very distant object that lies some ten billion light-years away from us. This grouping of galaxies certainly lives up to its nickname; it is the largest known galaxy cluster in the distant Universe and contains several hundred galaxies. What’s more, new NASA/ESA Hubble Space Telescope observations show that it is actually some 43 percent heavier than previously thought, with a mass some three million billion times the mass of the Sun — which is 3000 times the mass of our own galaxy, the Milky Way. A small fraction of the cluster’s immense mass is locked …

31 March 2014: In this new Hubble image, we can see an almost face-on view of the galaxy NGC 1084. At first glance, this galaxy is pretty unoriginal. Like the majority of galaxies that we observe it is a spiral galaxy, and, as with about half of all spirals, it has no bar running through its loosely wound arms. However, although it may seem unremarkable on paper, NGC 1084 is actually a near-perfect example of this type of galaxy — and Hubble has a near-perfect view of it. NGC 1084 has hosted several violent events known as supernovae — explosions that occur when massive stars, many times more massive than the Sun, approach their twilight years. As the fusion processes in their cores run out of fuel and come to an end, these stellar giants collapse, blowing off their outer layers in a violent explosion. Supernovae can often briefly outshine an entire galaxy, …

24 March 2014: Galaxy clusters are some of the most massive structures that can be found in the Universe — large groups of galaxies bound together by gravity. This image from the NASA/ESA Hubble Space Telescope reveals one of these clusters, known as MACS J0454.1-0300. Each of the bright spots seen here is a galaxy, and each is home to many millions, or even billions, of stars. Astronomers have determined the mass of MACS J0454.1-0300 to be around 180 trillion times the mass of the Sun. Clusters like this are so massive that their gravity can even change the behaviour of space around them, bending the path of light as it travels through them, sometimes amplifying it and acting like a cosmic magnifying glass. Thanks to this effect, it is possible to see objects that are so far away from us that they would otherwise be too faint to be detected. In this …

17 March 2014: This new Hubble image is centred on NGC 5793, a spiral galaxy over 150 million light-years away in the constellation of Libra. This galaxy has two particularly striking features: a beautiful dust lane and an intensely bright centre — much brighter than that of our own galaxy, or indeed those of most spiral galaxies we observe. NGC 5793 is a Seyfert galaxy. These galaxies have incredibly luminous centres that are thought to be caused by hungry supermassive black holes — black holes that can be billions of times the size of the Sun — that pull in and devour gas and dust from their surroundings. This galaxy is of great interest to astronomers for many reasons. For one, it appears to house objects known as masers. Whereas lasers emit visible light, masers emit microwave radiation [1]. Naturally occurring masers, like those observed in NGC 5793, can tell us a lot …

10 March 2014: They say the flap of a butterfly's wings can set off a tornado on the other side of the world. But what happens when a butterfly flaps its wings in the depths of space? This cosmic butterfly is a nebula known as AFGL 4104, or Roberts 22. Caused by a star that is nearing the end of its life and has shrugged off its outer layers, the nebula emerges as a cosmic chrysalis to produce this striking sight. Studies of the lobes of Roberts 22 have shown an amazingly complex structure, with countless intersecting loops and filaments. A butterfly's life span is counted in weeks; although on a much longer timescale, this stage of life for Roberts 22 is also transient. It is currently a preplanetary nebula, a short-lived phase that begins once a dying star has pushed much of the material in its outer layers into space, and ends …

3 March 2014: Spiral galaxy Messier 82 has long been known for its remarkable starburst activity, caused by interactions with its near neighbour Messier 81, and has been the subject of intense study for many years. On 21 January 2014, astronomers at the University of London Observatory in London, UK, pointed their telescope at the galaxy and spied something peculiar… an intensely bright spot seemed to have suddenly appeared within the galaxy [1]. This bright spot is actually a new supernova known as SN 2014J — the closest supernova to Earth in recent decades! Since its discovery, SN 2014J has been confirmed as a type Ia supernova, making it the closest of its type to Earth in over 40 years (since SN 1972E) [2]. This new NASA/ESA Hubble Space Telescope image is set against a previous mosaic of Messier 82 from 2006 (heic0604a), and shows the supernova as an intensely bright spot towards …

24 February 2014: This stunning new Hubble image shows a small part of the Large Magellanic Cloud, one of the closest galaxies to our own. This collection of small baby stars, most weighing less than the Sun, form a young stellar cluster known as LH63. This cluster is still half-embedded in the cloud from which it was born, in a bright star-forming region known as the emission nebula LHA 120-N 51, or N51. This is just one of the hundreds of star-forming regions filled with young stars spread throughout the Large Magellanic Cloud. The burning red intensity of the nebulae at the bottom of the picture illuminates wisps of gas and dark dust, each spanning many light-years. Moving up and across, bright stars become visible as sparse specks of light, giving the impression of pin-pricks in a cosmic cloak. This patch of sky was the subject of observation by Hubble's WFPC2 camera. Looking …

17 February 2014: The dominating figure in the middle of this new Hubble image is a galaxy known as MCG-03-04-014. It belongs to a class of galaxies called luminous infrared galaxies — galaxies that are incredibly bright in the infrared part of the spectrum. This galaxy's status as a luminous infrared galaxy makes it part of an interesting astronomical question: starbursts versus monsters, a debate over how these galaxies are powered. Why are they so luminous in the infrared? Is it due to a recent burst of star formation, or a fiercely powerful "monster" black hole lurking at their core — or a mix of the two? The answer is still unclear. This new image of MCG-03-04-014 shows bright sparks of star formation dotted throughout the galaxy, with murky dust lanes obscuring a bright central bulge. The galaxy seems to show evidence of disruption; at the top of the galaxy you can see …

10 February 2014: Named after its discoverer, the French-Armenian astronomer Agop Terzan, this is the globular cluster Terzan 7 — a densely packed ball of stars bound together by gravity. It lies just over 75 000 light-years away from us on the other side of our galaxy, the Milky Way. It is a peculiar cluster, quite unlike others we observe, making it an intriguing object of study for astronomers. Evidence shows that Terzan 7 used to belong to a small galaxy called the Sagittarius Dwarf Galaxy, a mini-galaxy discovered in 1994. This galaxy is currently colliding with, and being absorbed by, the Milky Way, which is a monster in size when compared to this tiny one. It seems that this cluster has already been kidnapped from its former home and now is part of our own galaxy. Astronomers recently discovered that all the stars in Terzan 7 were born at around the same …

3 February 2014: This striking new image, captured by the NASA/ESA Hubble Space Telescope, reveals a star in the process of forming within the Chamaeleon cloud. This young star is throwing off narrow streams of gas from its poles — creating this ethereal object known as HH 909A. These speedy outflows collide with the slower surrounding gas, lighting up the region. When new stars form, they gather material hungrily from the space around them. A young star will continue to feed its huge appetite until it becomes massive enough to trigger nuclear fusion reactions in its core, which light the star up brightly. Before this happens, new stars undergo a phase during which they violently throw bursts of material out into space. This material is ejected as narrow jets that streak away into space at breakneck speeds of hundreds of kilometres per second, colliding with nearby gas and dust and lighting up the …

27 January 2014: A piece of art? A time-lapse photo? A flickering light show? At first glance, this image looks nothing like the images that we are used to seeing from Hubble. The distinctive splashes of colour must surely be a piece of modern art, or an example of the photographic technique of "light painting". Or, could they be the trademark tracks of electrically charged particles in a bubble chamber? On a space theme, how about a time-lapse of the paths of orbiting satellites? The answer? None of the above. In fact, this is a genuine frame that Hubble relayed back from an observing session. Hubble uses a Fine Guidance System (FGS) in order to maintain stability whilst performing observations. A set of gyroscopes measures the attitude of the telescope, which is then corrected by a set of reaction wheels. In order to compensate for gyroscopic drift, the FGS locks onto a fixed …

20 January 2014: In this new Hubble image two objects are clearly visible, shining brightly. When they were first discovered in 1979, they were thought to be separate objects — however, astronomers soon realised that these twins are a little too identical! They are close together, lie at the same distance from us, and have surprisingly similar properties. The reason they are so similar is not some bizarre coincidence; they are in fact the same object. These cosmic doppelgangers make up a double quasar known as QSO 0957+561, also known as the "Twin Quasar", which lies just under 14 billion light-years from Earth. Quasars are the intensely powerful centres of distant galaxies. So, why are we seeing this quasar twice? Some 4 billion light-years from Earth — and directly in our line of sight — is the huge galaxy YGKOW G1. This galaxy was the first ever observed gravitational lens, an object with …

13 January 2014: In this new image Hubble peeks into the Coma Cluster, a massive gathering of galaxies located towards the constellation of Coma Berenices. This large cluster is around 350 million light-years away from us and contains over 1000 identified galaxies, the majority of which are elliptical. The bright, saucer-shaped objects surrounded by misty halos in this image are galaxies, each of them host to many millions of stars. The background of the image is full of distant galaxies, many of them with spiral shapes, that are located much further away and do not belong to the cluster. Visible in this image are three galaxies within the Coma Cluster: IC 4041 (far left), IC 4042 (centre), and GP 236 (right). A version of this image was entered into the Hidden Treasures image processing competition by contestant Nick Rose. Links Hubble's sweeping view of the Coma cluster Wide-field view of the Coma cluster …

6 January 2014: Floating at the centre of this new Hubble image is a lidless purple eye, staring back at us through space. This ethereal object, known officially as [SBW2007] 1 but sometimes nicknamed SBW1, is a nebula with a giant star at its centre. The star was originally twenty times more massive than our Sun, and is now encased in a swirling ring of purple gas, the remains of the distant era when it cast off its outer layers via violent pulsations and winds. But the star is not just any star; scientists say that it is destined to go supernova! 26 years ago, another star with striking similarities went supernova — SN 1987A. Early Hubble images of SN 1987A show eerie similarities to SBW1. Both stars had identical rings of the same size and age, which were travelling at similar speeds; both were located in similar HII regions; and they had …

30 December 2013: The 1st of March 1780 was a particularly productive night for Charles Messier. Combing the constellation of Leo for additions to his grand astronomical catalogue, he struck on not one, but two, new objects. One of those objects is seen here: Messier 65. "Nebula discovered in Leo: It is very faint and contains no star," he jotted down in his notebook. But he was wrong — as we now know, Messier 65 is a spiral galaxy containing billions upon billions of stars. All Messier saw was a faint diffuse light, nothing like the fine detail here, so we can forgive his mistake. If he had had access to a telescope like Hubble, he could have spied these stunning, tightly wound purple spiral arms and dark dust lanes, encircling a bright centre crammed with stars. Almost exactly 233 years later in March of this year, one of the stars within Messier …

23 December 2013: Located some 25 million light-years away, this new Hubble image shows spiral galaxy ESO 373-8. Together with at least seven of its galactic neighbours, this galaxy is a member of the NGC 2997 group. We see it side-on as a thin, glittering streak across the sky, with all its contents neatly aligned in the same plane. We see so many galaxies like this — flat, stretched-out pancakes — that our brains barely process their shape. But let us stop and ask: Why are galaxies stretched out and aligned like this? Try spinning around in your chair with your legs and arms out. Slowly pull your legs and arms inwards, and tuck them in against your body. Notice anything? You should have started spinning faster. This effect is due to conservation of angular momentum, and it’s true for galaxies, too. This galaxy began life as a humungous ball of slowly rotating …

16 December 2013: Look at the bright star in the middle of this image. Achoo! It has just sneezed. This sight will only last for a few thousand years — a blink of an eye in the young star's life. If you could carry on watching for a few years you would realise it's not just one sneeze, but a sneezing fit. This young star is firing off salvos of super-hot, super-fast gas — Achoo! Achoo! — before it finally exhausts itself. These bursts of gas have shaped the turbulent surroundings, creating structures known as Herbig-Haro objects. These objects are formed from the star's energetic "sneezes". These salvos can contain as much mass as our home planet, and cannon into nearby clouds of gas at hundreds of kilometres per second. Shock waves form, such as the U-shape below this star. Unlike most other astronomical phenomena, as the waves crash outwards, they can be …

9 December 2013: This new Hubble image shows a handful of galaxies in the constellation of Eridanus (The River). NGC 1190, shown here on the right of the frame, stands apart from the rest; it belong to an exclusive club known as Hickson Compact Group 22 (HCG 22). There are four other members of this group, all of which lie out of frame: NGC 1189, NGC 1191, NGC 1192, and NGC 1199. The other galaxies shown here are nearby galaxies 2MASS J03032308-1539079 (centre), and dCAZ94 HCG 22-21 (left), both of which are not part of HCG 22. Hickson Compact Groups are incredibly tightly bound groups of galaxies. Their discoverer Paul Hickson observed only 100 of these objects, which he described in his HCG catalogue in the 1980s. To earn the Hickson Compact Group label, there must be at least four members — each one fairly bright and compact. These short-lived groups are thought …

2 December 2013: This new Hubble image shows a peculiar galaxy known as NGC 660, located around 45 million light-years away from us. NGC 660 is classified as a "polar ring galaxy", meaning that it has a belt of gas and stars around its centre that it ripped from a near neighbour during a clash about one billion years ago. The first polar ring galaxy was observed in 1978 and only around a dozen more have been discovered since then, making them something of a cosmic rarity. Unfortunately, NGC 660’s polar ring cannot be seen in this image, but has plenty of other features that make it of interest to astronomers – its central bulge is strangely off-kilter and, perhaps more intriguingly, it is thought to harbour exceptionally large amounts of dark matter. In addition, in late 2012 astronomers observed a massive outburst emanating from NGC 660 that was around ten times as …

25 November 2013: This sprinkling of cosmic glitter makes up the galaxy known as ESO 149-3, located some 20 million light-years away from us. It is an example of an irregular galaxy, characterised by its amorphous, undefined shape — a property that sets it apart from its perhaps more photogenic spiral and elliptical relatives. Around one quarter of all galaxies are thought to be irregular-type galaxies. In this image taken with the NASA/ESA Hubble Space Telescope ESO 149-3 can be seen as a smattering of golden and blue stars, with no apparent central nucleus or arm structure. The surrounding sky is rich in other more distant galaxies, visible as small, colourful streaks and dashes. A version of this image was submitted to the Hubble's Hidden Treasures image processing competition by contestant Luca Limatola.

18 November 2013: This image from Hubble’s Wide Field and Planetary Camera 2 (WFPC2) is likely the best of ancient and brilliant quasar 3C 273, which resides in a giant elliptical galaxy in the constellation of Virgo (The Virgin). Its light has taken some 2.5 billion years to reach us. Despite this great distance, it is still one of the closest quasars to our home. It was the first quasar ever to be identified, and was discovered in the early 1960s by astronomer Allan Sandage. The term quasar is an abbreviation of the phrase “quasi-stellar radio source”, as they appear to be star-like on the sky. In fact, quasars are the intensely powerful centres of distant, active galaxies, powered by a huge disc of particles surrounding a supermassive black hole. As material from this disc falls inwards, some quasars — including 3C 273 — have been observed to fire off super-fast jets into …

11 November 2013: The NASA/ESA Hubble Space Telescope has snapped the best ever image of the Antennae Galaxies. Hubble has released images of these stunning galaxies twice before, once using observations from its Wide Field and Planetary Camera 2 (WFPC2) in 1997, and again in 2006 from the Advanced Camera for Surveys (ACS). Each of Hubble’s images of the Antennae Galaxies has been better than the last, due to upgrades made during the famous servicing missions, the last of which took place in 2009. The galaxies — also known as NGC 4038 and NGC 4039 — are locked in a deadly embrace. Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years sparring with one another. This clash is so violent that stars have been ripped from their host galaxies to form a streaming arc between the two. In wide-field images of the pair …

4 November 2013: Supernovae are intensely bright objects. They are formed when a star reaches the end of its life with a dramatic explosion, expelling most of its material out into space. The subject of this new Hubble image, spiral galaxy NGC 6984, played host to one of these explosions back in 2012, known as SN 2012im. Now, another star has exploded, forming supernova SN 2013ek — visible in this image as the prominent, star-like bright object just slightly above and to the right of the galaxy's centre. SN 2012im is known as a Type Ic supernova, while the more recent SN 2013ek is a Type Ib. Both of these types are caused by the core collapse of massive stars that have shed — or lost — their outer layers of hydrogen. Type Ic supernovae are thought to have lost more of their outer envelope than Type Ib, including a layer of helium. …

28 October 2013: Shining brightly in this Hubble image is our closest stellar neighbour: Proxima Centauri. Proxima Centauri lies in the constellation of Centaurus (The Centaur), just over four light-years from Earth. Although it looks bright through the eye of Hubble, as you might expect from the nearest star to the Solar System, Proxima Centauri is not visible to the naked eye. Its average luminosity is very low, and it is quite small compared to other stars, at only about an eighth of the mass of the Sun. However, on occasion, its brightness increases. Proxima is what is known as a “flare star”, meaning that convection processes within the star’s body make it prone to random and dramatic changes in brightness. The convection processes not only trigger brilliant bursts of starlight but, combined with other factors, mean that Proxima Centauri is in for a very long life. Astronomers predict that this star will …

21 October 2013: This new NASA/ESA Hubble Space Telescope picture shows C/2012 S1, better known as Comet ISON, a high-profile celestial visitor to the Solar System. Hubble has already snapped this comet twice this year (opo1314a, opo1331a), but for some time it was temporarily blocked from view by the Sun. It was spotted again in August 2013, and this new image shows the comet as it appeared in our skies in early October. ISON will be brightest in our skies in late November, just before and after it hurtles past the Sun. As it gets brighter, it may even become visible as a naked eye object, before it fades throughout December — the month of its closest approach to Earth. Depending on its fate as it passes close to the Sun, it could become spectacular or, on the contrary, it could completely disintegrate. Many observatories, as well as several ESA and NASA missions, …

14 October 2013: This Hubble Picture of the Week is dedicated to the over 200 000 Facebook fans of ESA/Hubble, who share our passion for the NASA/ESA Hubble Space Telescope and the discoveries it brings. We thank you for staying in touch with us!  The image, captured by the NASA/ESA Hubble Space Telescope, shows part of NGC 3621, an unusual spiral galaxy located over 20 million light-years away in the constellation of Hydra (The Water Snake). The small, bright nucleus on the right of the image does not have the significant bulge of older stars that is common in spiral galaxies, marking NGC 3621 as a "pure-disc" galaxy. Many luminous clumps of blue young stars are scattered along the loose spiral arms, which are partially obscured by the dark dust lanes snaking across the frame. This galaxy is very useful for astronomers; some of its brightest stars can be used to estimate extragalactic …

7 October 2013: This image, not unlike a pointillist painting, shows the star-studded centre of the Milky Way towards the constellation of Sagittarius. The crowded centre of our galaxy contains numerous complex and mysterious objects that are usually hidden at optical wavelengths by clouds of dust — but many are visible here in these infrared observations from Hubble. However, the most famous cosmic object in this image still remains invisible: the monster at our galaxy’s heart called Sagittarius A*. Astronomers have observed stars spinning around this supermassive black hole (located right in the centre of the image), and the black hole consuming clouds of dust as it affects its environment with its enormous gravitational pull. Infrared observations can pierce through thick obscuring material to reveal information that is usually hidden to the optical observer. This is the best infrared image of this region ever taken with Hubble, and uses infrared archive data from …

30 September 2013: This NASA/ESA Hubble Space Telescope image shows the planetary nebula NGC 2452, located in the southern constellation of Puppis. The blue haze across the frame is what remains of a star like our Sun after it has depleted all its fuel. When this happens, the core of the star becomes unstable and releases huge numbers of incredibly energetic particles that blow the star's atmosphere away into space. At the centre of this blue cloud lies what remains of the nebula's progenitor star. This cool, dim, and extremely dense star is actually a pulsating white dwarf, meaning that its brightness varies over time as gravity causes waves that pulse throughout the small star's body. NGC 2452 was discovered by Sir John Herschel in 1847. He initially defined it as "an object whose nature I cannot make out. It is certainly not a star, nor a close double star [...] I should …

23 September 2013: This image shows the massive galaxy cluster MACS J0152.5-2852, captured in detail by the NASA/ESA Hubble Space Telescope's Wide Field Camera 3. Almost every object seen here is a galaxy, each containing billions of stars. Galaxies are not usually randomly distributed in space, but instead appear in concentrations of hundreds, held together by their mutual gravity. Elliptical galaxies, like the yellow fuzzy objects seen in the image, are most often found close to the centres of galaxy clusters, while spirals, such as the bluish patches, are usually found to be further out and more isolated. A version of this image obtained tenth prize in the Hubble's Hidden Treasures image processing competition, entered by contestant Judy Schmidt.

16 September 2013: This new image, snapped by NASA/ESA Hubble Space Telescope, shows the star HD 184738, also known as Campbell’s hydrogen star. It is surrounded by plumes of reddish gas — the fiery red and orange hues are caused by glowing gases, including hydrogen and nitrogen.HD 184738 is at the centre of a small planetary nebula. The star itself is known as a  [WC] star, a rare class resembling their much more massive counterparts — Wolf-Rayet stars. These stars are named after two French astronomers, Charles Wolf and Georges Rayet, who first identified them in the mid-nineteenth century. Wolf-Rayet stars are hot stars, perhaps 20 times more massive than the Sun, that are rapidly blowing away material and losing mass. [WC] stars are rather different: they are low-mass Sun-like stars at the end of their lives. While these stars have recently ejected much of their original mass, the hot stellar core is …

9 September 2013: The glittering specks in this image, resembling a distant flock of flying birds, are the stars that make up the dwarf galaxy ESO 540-31. Captured in this new image from the NASA/ESA Hubble Space Telescope, the dwarf galaxy lies just over 11 million light-years from Earth, in the constellation of Cetus (The Whale). The background of this image is full of many other galaxies, all located at vast distances from us. Dwarf galaxies are the among the smaller and dimmer members of the galactic family, typically only containing around a few hundred million stars. Although this sounds like a large number, it is small when compared to spiral galaxies like our Milky Way, which are made up of hundreds of billions of stars. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Luca Limatola.

2 September 2013: Lying over 110 million light-years away from Earth in the constellation of Antlia (The Air Pump) is the spiral galaxy IC 2560, shown here in an image from NASA/ESA Hubble Space Telescope. At this distance it is a relatively nearby spiral galaxy, and is part of the Antlia cluster — a group of over 200 galaxies held together by gravity. This cluster is unusual; unlike most other galaxy clusters, it appears to have no dominant galaxy within it. In this image, it is easy to spot IC 2560's spiral arms and barred structure. This spiral is what astronomers call a Seyfert-2 galaxy, a kind of spiral galaxy characterised by an extremely bright nucleus and very strong emission lines from certain elements — hydrogen, helium, nitrogen, and oxygen. The bright centre of the galaxy is thought to be caused by the ejection of huge amounts of super-hot gas from the region …

26 August 2013: The NASA/ESA Hubble Space Telescope has captured this image of PGC 10922, an example of a lenticular galaxy — a galaxy type that lies on the border between ellipticals and spirals. Seen face-on, the image shows the disc and tightly-wound spiral structures of dark dust encircling the bright centre of the galaxy. There is also a remarkable outer halo of faint wide arcs or shells extending outwards, covering much of the picture. These are likely to have been formed by a gravitational encounter or even a merger with another galaxy. Some dust also appears to have escaped from the central structure and has spread out across the inner shells. An extraordinarily rich background of more remote galaxies can also be seen in the image. A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Judy Schmidt.

19 August 2013: At first glance, this Hubble picture appears to capture two space colossi entangled in a fierce celestial battle, with two galaxies entwined and merging to form one. But this shows just how easy it is to misinterpret the jumble of sparkling stars and get the wrong impression — as it’s all down to a trick of perspective. By chance, these galaxies appear to be aligned from our point of view. In the foreground, the irregular dwarf galaxy PGC 16389 — seen here as a cloud of stars — covers its neighbouring galaxy APMBGC 252+125-117, which appears edge-on as a streak. This wide-field image also captures many other more distant galaxies, including a quite prominent face-on spiral towards the right of the picture. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Luca Limatola.

12 August 2013: Astronomical pictures sometimes deceive us with tricks of perspective. Right in the centre of this image, two spiral galaxies appear to be suffering a spectacular collision, with a host of stars appearing to flee the scene of the crash in a chaotic stampede. However, this is just a trick of perspective. It is true that two spiral galaxies are colliding, but they are millions of light-years away, far beyond the cloud of blue and red stars near the merging spiral. This sprinkling of stars is actually an isolated, irregular dwarf galaxy named ESO 489-056. The dwarf galaxy is actually much more distant than many bright stars in the foreground of the image, which are located much closer to us, in the Milky Way. ESO 489-056 is located 16 million light-years from Earth in the constellation of Canis Major (The Greater Dog), in our local Universe. It is composed of a …

5 August 2013: Don’t be fooled by the title; the mysterious, almost mystical bright light emerging from these thick, ominous clouds is actually a telltale sign of star formation. Here, a very young star is being born in the guts of the dark cloud LDN 43 — a massive blob of gas, dust, and ices, gathered 520 light-years from Earth in the constellation of Ophiuchus (The Serpent Bearer). Stars are born from cosmic dust and gas, which floats freely in space until gravity forces it to bind together. The hidden newborn star in this image, revealed only by light reflected onto the plumes of the dark cloud, is named RNO 91. It is what astronomers call a pre-main sequence star, meaning that it has not yet started burning hydrogen in its core. The energy that allows RNO 91 to shine comes from gravitational contraction. The star is being compressed by its own weight …

29 July 2013: Another treasure unearthed from the Hubble archives, this beautiful image shows a spiral galaxy named NGC 4517. Slightly bigger than our Milky Way, it is seen edge-on, crowned by a very bright star. The star is actually much closer to us than the galaxy, explaining why it appears to be so big and bright in the picture.  NGC 4517 is located approximately 40 million light-years away in the constellation of Virgo (The Virgin). It has a bright centre, but this is not visible in this Hubble image. Its orientation has led to it being included in many studies of globular clusters, clumps of stars that orbit the centres of galaxies like satellites. The galaxy was discovered in 1784 by William Herschel, who described this region as having “a pretty bright star situated exactly north of the centre of an extended milky ray”. Of course the “milky ray” seen by Herschel …

22 July 2013: This striking cosmic whirl is the centre of galaxy NGC 524, as seen with the NASA/ESA Hubble Space Telescope. This galaxy is located in the constellation of Pisces, some 90 million light-years from Earth. NGC 524 is a lenticular galaxy. Lenticular galaxies are believed to be an intermediate state in galactic evolution — they are neither elliptical nor spiral. Spirals are middle-aged galaxies with vast, pinwheeling arms that contain millions of stars. Along with these stars are large clouds of gas and dust that, when dense enough, are the nurseries where new stars are born. When all the gas is either depleted or lost into space, the arms gradually fade away and the spiral shape begins to weaken. At the end of this process, what remains is a lenticular galaxy — a bright disc full of old, red stars surrounded by what little gas and dust the galaxy has managed …

15 July 2013: The constellation of Virgo (The Virgin) is the largest of the Zodiac constellations, and the second largest overall after Hydra (The Water Snake). Its most appealing feature, however, is the sheer number of galaxies that lie within it. In this picture, among a crowd of face- and edge-on spiral, elliptical, and irregular galaxies, lies NGC 4866, a lenticular galaxy situated about 80 million light-years from Earth. Lenticular galaxies are somewhere between spirals and ellipticals in terms of shape and properties. From the picture, we can appreciate the bright central bulge of NGC 4886, which contains primarily old stars, but no spiral arms are visible. The galaxy is seen from Earth as almost edge-on, meaning that the disc structure — a feature not present in elliptical galaxies — is clearly visible. Faint dust lanes trace across NGC 4866 in this image, obscuring part of the galaxy’s light. To the right of …

8 July 2013: This NASA/ESA Hubble Space Telescope image shows the planetary nebula IC 289, located in the northern constellation of Cassiopeia. Formerly a star like our Sun, it is now just a cloud of ionised gas being pushed out into space by the remnants of the star’s core, visible as a small bright dot in the middle of the cloud. Weirdly enough, planetary nebulae have nothing to do with planets. Early observers, when looking through small telescopes, could only see undefined, smoky forms that looked like gaseous planets — hence the name. The term has stuck even though modern telescopes like Hubble have made it clear that these objects are not planets at all, but the outer layers of dying stars being thrown off into space. Stars shine as a result of nuclear fusion reactions in their cores, converting hydrogen to helium. All stars are stable, balancing the inward push caused by …

1 July 2013: This is the spiral galaxy NGC 3185, located some 80 million light-years away from us in the constellation of Leo (The Lion). The image shows the galaxy’s spiral arms, which can be traced from the centre of the galaxy out towards the rim, where they appear to meet a sparkling blue disc. At the centre of NGC 3185 is a small but very bright nucleus containing a supermassive black hole. Black holes like this one can have masses many thousands of times that of the Sun, and they become active when matter falls towards them. When this happens the black hole lights up, sending away streams of particles and radiation at almost the speed of light. NGC 3185 is a member of a small, four-galaxy group called Hickson 44, which has a celebrity in its midsts — the group is also home to another spiral galaxy called NGC 3190. NGC …

24 June 2013: Looking towards the constellation of Triangulum (The Triangle), in the northern sky, lies the galaxy pair MRK 1034. The two very similar galaxies, named PGC 9074 and PGC 9071, are close enough to one another to be bound together by gravity, although no gravitational disturbance can yet be seen in the image. These objects are probably only just beginning to interact gravitationally. Both are spiral galaxies, and are presented to our eyes face-on, so we are able to appreciate their distinctive shapes. On the left of the image, spiral galaxy PGC 9074 shows a bright bulge and two spiral arms tightly wound around the nucleus, features which have led scientists to classify it as a type Sa galaxy. Close by, PGC 9071 — a type Sb galaxy — although very similar and almost the same size as its neighbour, has a fainter bulge and a slightly different structure to its …

17 June 2013: The NASA/ESA Hubble Space Telescope has captured this image of nearby spiral galaxy Messier 61, also known as NGC 4303. The galaxy, located only 55 million light-years away from Earth, is roughly the size of the Milky Way, with a diameter of around 100 000 light-years. The galaxy is notable for one particular reason — six supernovae have been observed within Messier 61, a total that places it in the top handful of galaxies alongside Messier 83, also with six, and NGC 6946, with a grand total of nine observed supernovae. In this Hubble image the galaxy is seen face-on as if posing for a photograph, allowing us to study its structure closely. The spiral arms can be seen in stunning detail, swirling inwards to the very centre of the galaxy, where they form a smaller, intensely bright spiral. In the outer regions, these vast arms are sprinkled with bright …

10 June 2013: The contorted object captured by Hubble in this picture is IRAS 22491-1808, also known as the South America Galaxy. It is an ultraluminous infrared galaxy (ULIRG) that emits a huge amount of light at infrared wavelengths. The reason for this intense infrared emission lies in an episode of strong star formation activity, which was set off by a collision between two interacting galaxies.  In this image the twisted shape hides a number of features. In the central region, which is very complex and disturbed, scientists have been able to distinguish two nuclei, remains of the two different galaxies that are currently colliding to form a new one. IRAS 22491-1808 is amongst the most luminous of these types of galaxies, and is considered to be mid-way through its merging stage. The centre of this appealing object also shows several intense star-forming knots which, as seen in the picture, actually outshine the …

3 June 2013: Unlike the venomous fictional plants that share its name, the Trifid of the North, otherwise known as the Northern Trifid or NGC 1579, poses no threat to your vision. The nebula’s moniker is inspired by the better-known Messier 20, the Trifid Nebula, which lies very much further south in the sky and displays strikingly similar swirling clouds of gas and dust. The Trifid of the North is a large, dusty region that is currently forming new stars. These stars are very hot and therefore appear to be very blue. During their short lives they radiate strongly into the gas surrounding them, causing it to glow brightly. Many regions like the Trifid of the North — named H II regions — are clumpy and strangely shaped due to the powerful winds emanating from the stars within them. H II regions also have relatively short lives, furiously forming baby stars until the …

27 May 2013: This new image from the NASA/ESA Hubble Space Telescope captures an ongoing cosmic collision between two galaxies — a spiral galaxy is in the process of colliding with a lenticular galaxy. The collision looks almost as if it is popping out of the screen in 3D, with parts of the spiral arms clearly embracing the lenticular galaxy’s bulge. The image also reveals further evidence of the collision. There is a bright stream of stars coming out from the merging galaxies, extending out towards the right of the image. The bright spot in the middle of the plume, known as ESO 576-69, is what makes this image unique. This spot is believed to be the nucleus of the former spiral galaxy, which was ejected from the system during the collision and is now being shredded by tidal forces to produce the visible stellar stream. A version of this image was entered …

20 May 2013: This beautiful, glittering swirl is named, rather unpoetically, J125013.50+073441.5. A glowing haze of material seems to engulf the galaxy, stretching out into space in different directions and forming a fuzzy streak in this image. It is a starburst galaxy — a name given to galaxies that show unusually high rates of star formation. The regions where new stars are being born are highlighted by sparkling bright blue regions along the galactic arms. Studying starburst galaxies can tell us a lot about galactic evolution and star formation. These galaxies start off with huge amounts of gas, which is used to form new stars. This period of furious star formation is only a phase; once all the gas is used up, this starbirth slows down. Other famous starbursts captured by Hubble include the Antennae Galaxies and Messier 82, the latter of which is forming new stars ten times faster than our galaxy, …

13 May 2013: This Hubble image shows the galaxy cluster Abell S1077. Galaxy clusters are large groupings of galaxies, each of them including millions of stars. They are the largest existing structures in the Universe to be held together by their gravity. The amount of matter condensed in such groupings is so high that their gravity is enough to warp the fabric of spacetime, distorting the path that light takes when it travels through the cluster. In some cases, this phenomenon produces an effect somewhat like a magnifying lens, allowing us to see objects that are aligned behind the cluster and which would otherwise be undetectable from Earth. In this image, you see stretched stripes that look like scratches on a lens but are, in fact, galaxies whose light is heavily distorted by the gravitational field of the cluster. Astronomers use tools like the NASA/ESA Hubble Space Telescope and the effects of gravitational …

6 May 2013: When we look into the distant cosmos, the great majority of the objects we see are galaxies: immense gatherings of stars, planets, gas, dust, and dark matter, showing up in all kind of shapes. This Hubble picture registers several, but the galaxy catalogued as 2MASX J05210136-2521450 stands out at a glance due to its interesting shape. This object is an ultraluminous infrared galaxy which emits a tremendous amount of light at infrared wavelengths. Scientists connect this to intense star formation activity, triggered by a collision between two interacting galaxies. The merging process has left its signs: 2MASX J05210136-2521450 presents a single, bright nucleus and a spectacular outer structure that consists of a one-sided extension of the inner arms, with a tidal tail heading in the opposite direction, formed from material ripped out from the merging galaxies by gravitational forces. The image is a combination of exposures taken by Hubble’s Advanced …

29 April 2013: These delicate wisps of gas make up an object known as SNR B0519-69.0, or SNR 0519 for short. The thin, blood-red shells are actually the remnants from when an unstable progenitor star exploded violently as a supernova around 600 years ago. There are several types of supernova, but for SNR 0519 the star that exploded is known to have been a white dwarf star — a Sun-like star in the final stages of its life. SNR 0519 is located over 150 000 light-years from Earth in the southern constellation of Dorado (The Dolphinfish), a constellation that also contains most of our neighbouring galaxy the Large Magellanic Cloud (LMC). Because of this, this region of the sky is full of intriguing and beautiful deep sky objects. The LMC orbits the Milky Way galaxy as a satellite and is the fourth largest in our group of galaxies, the Local Group. SNR 0519 …

22 April 2013: The Universe is rarely static, although the timescales involved can be very long. Since modern astronomical observations began we have been observing the birthplaces of new stars and planets, searching for and studying the subtle changes that help us to figure out what is happening within. The bright spot located at the edge of the bluish fan-shaped structure in this Hubble image is a young star called V* PV Cephei, or PV Cep. It is a favourite target for amateur astronomers because the fan-shaped nebulosity, known as GM 1-29 or Gyulbudaghian’s Nebula, changes over a timescale of months. The brightness of the star has also varied over time. Images of PV Cep taken in 1952 showed a nebulous streak, similar to a comet’s tail. However, these had vanished when new images of the star were obtained some twenty-five years later. Instead, the blue fan-shaped nebula had appeared. Twenty-five years is …

15 April 2013: Globular clusters are relatively common in our sky, and generally look similar. However, this image, taken using the NASA/ESA Hubble Space Telescope, shows a unique example of such a cluster — Palomar 2. Palomar 2 is part of a group of 15 globulars known as the Palomar clusters. These clusters, as the name suggests, were discovered in survey plates from the first Palomar Observatory Sky Survey in the 1950s, a project that involved some of the most well-known astronomers of the day, including Edwin Hubble. They were discovered quite late because they are so faint — each is either extremely remote, very heavily hidden behind blankets of dust, or has a very small number of remaining stars. This particular cluster is unique in more than one way. For one, it is the only globular cluster that we see in this part of the sky, the northern constellation of Auriga (The …

8 April 2013: The soft glow in the picture above is NGC 2768, an elliptical galaxy located in the northern constellation of Ursa Major (The Great Bear). It appears here as a bright oval on the sky, surrounded by a wide, fuzzy cloud of material. This image, taken by the NASA/ESA Hubble Space Telescope, shows the dusty structure encircling the centre of the galaxy, forming a knotted ring around the galaxy’s brightly glowing middle. Interestingly, this ring lies perpendicular to the plane of NGC 2768 itself, stretching up and out of the galaxy. The dust in NGC 2768 forms an intricate network of knots and filaments. In the centre of the galaxy are two tiny, S-shaped symmetric jets. These two flows of material travel outwards from the galactic centre along curved paths, and are masked by the tangle of dark dust lanes that spans the body of the galaxy. These jets are a …

1 April 2013: Visible as a small, sparkling hook in the dark sky, this beautiful object is known as J082354.96+280621.6, or J082354.96 for short. It is a starburst galaxy, so named because of the incredibly (and unusually) high rate of star formation occurring within it. One way in which astronomers probe the nature and structure of galaxies like this is by observing the behaviour of their dust and gas components; in particular, the Lyman-alpha emission. This occurs when electrons within a hydrogen atom fall from a higher energy level to a lower one, emitting light as they do so. This emission is interesting because this light leaves its host galaxy only after extensive scattering in the nearby gas — meaning that this light can be used as a pretty direct probe of what a galaxy is made up of. The study of this Lyman-alpha emission is common in very distant galaxies, but now …

25 March 2013: The object in this image is Jonckheere 900 or J 900, a planetary nebula — glowing shells of ionised gas pushed out by a dying star. Discovered in the early 1900s by astronomer Robert Jonckheere, the dusty nebula is small but fairly bright, with a relatively evenly spread central region surrounded by soft wispy edges. Despite the clarity of this Hubble image, the two objects in the picture above can be confusing for observers. J 900’s nearby companion, a faint star in the constellation of Gemini, often causes problems for observers because it is so close to the nebula — when seeing conditions are bad, this star seems to merge into J 900, giving it an elongated appearance. Hubble’s position above the Earth’s atmosphere means that this is not an issue for the space telescope. Astronomers have also mistakenly reported observations of a double star in place of these two …

18 March 2013: This charming and bright galaxy, known as IRAS 23436+5257, was captured by the the NASA/ESA Hubble Space Telescope. It is located in the northern constellation of Cassiopeia, which is named after an arrogant, vain, and yet beautiful mythical queen. The twisted, wormlike structure of this galaxy is most likely the result of a collision and subsequent merger of two galaxies. Such interactions are quite common in the Universe, and they can range from minor interactions involving a satellite galaxy being caught by a spiral arm, to major galactic crashes. Friction between the gas and dust during a collision can have a major effect on the galaxies involved, morphing the shape of the original galaxies and creating interesting new structures. When you look up at the calm and quiet night sky it is not always easy to picture it as a dynamic and vibrant environment with entire galaxies in motion, spinning …

11 March 2013: Galaxies can take many forms — elliptical blobs, swirling spiral arms, bulges, and discs are all known components of the wide range of galaxies we have observed using telescopes like the NASA/ESA Hubble Space Telescope. However, some of the more intriguing objects in the sky around us include ring galaxies like the one pictured above — Zw II 28. Ring galaxies are mysterious objects. They are thought to form when one galaxy slices through the disc of another, larger, one — as galaxies are mostly empty space, this collision is not as aggressive or as destructive as one might imagine. The likelihood of two stars physically colliding is minimal, and it is instead the gravitational effects of the two galaxies that causes the disruption. This disruption upsets the material in both galaxies, causing it to redistribute to form a dense central core, encircled by bright stars. All this commotion causes …

4 March 2013: This image, speckled with blue, white, and yellow light, shows part of the spiral galaxy IC 5052. Surrounded by distant stars and galaxies, it emits a bright blue-white glow which highlights its narrow, intricate structure. It is viewed side-on in the constellation of Pavo (The Peacock), in the southern sky. When spiral galaxies are viewed from this angle, it is very difficult to fully understand their properties and how they are arranged. IC 5052 is actually a barred spiral galaxy – its pinwheeling arms do not begin from the centre point but are instead attached to either end of a straight "bar" of stars that cuts through the galaxy's middle. Approximately two thirds of all spirals are barred, including the Milky Way. Bursts of pale blue light are visible across the galaxy's length, partially blocked out by weaving lanes of darker gas and dust. These are pockets of extremely hot …

25 February 2013: It may look like something from The Lord of the Rings, but this fiery swirl is actually a planetary nebula known as ESO 456-67. Set against a backdrop of bright stars, the rust-coloured object lies in the constellation of Sagittarius (The Archer), in the southern sky. Despite the name, these ethereal objects have nothing at all to do with planets; this misnomer came about over a century ago, when the first astronomers to observe them only had small, poor-quality telescopes. Through these, the nebulae looked small, compact, and planet-like — and so were labelled as such. When a star like the Sun approaches the end of its life, it flings material out into space. Planetary nebulae are the intricate, glowing shells of dust and gas pushed outwards from such a star. At their centres lie the remnants of the original stars themselves — small, dense white dwarf stars. In this …

18 February 2013: This image shows an object known as HH 151, a bright jet of glowing material trailed by an intricate, orange-hued plume of gas and dust. It is located some 460 light-years away in the constellation of Taurus (The Bull), near to the young, tumultuous star HL Tau. In the first few hundred thousand years of life, new stars like HL Tau pull in material that falls towards them from the surrounding space. This material forms a hot disc that swirls around the coalescing body, launching narrow streams of material from its poles. These jets are shot out at speeds of several hundred kilometres per second and collide violently with nearby clumps of dust and gas, creating wispy, billowing structures known as Herbig-Haro objects — like HH 151 seen in the image above. Such objects are very common in star-forming regions. They are short-lived, and their motion and evolution can actually …

11 February 2013: This large “flying V” is actually two distinct objects — a pair of interacting galaxies known as IC 2184. Both the galaxies are seen almost edge-on in the large, faint northern constellation of Camelopardalis (The Giraffe), and can be seen as bright streaks of light surrounded by the ghostly shapes of their tidal tails. These tidal tails are thin, elongated streams of gas, dust and stars that extend away from a galaxy into space. They occur when galaxies gravitationally interact with one another, and material is sheared from the outer edges of each body and flung out into space in opposite directions, forming two tails. They almost always appear curved, so when they are seen to be relatively straight, as in this image, it is clear that we are viewing the galaxies side-on. Also visible in this image are bursts of bright blue, pinpointing hot regions where the stars from …

4 February 2013: This thin, glittering streak of stars is the spiral galaxy ESO 121-6, which lies in the southern constellation of Pictor (The Painter's Easel). Viewed almost exactly side-on, the intricate structure of the swirling arms is hidden, but the full length of the galaxy can be seen — including the intense glow from the central bulge, a dense region of tightly packed young stars sitting at the centre of the spiral arms. Tendrils of dark dust can be seen across the frame, partially obscuring the bright centre of the galaxy and continuing out towards the smattering of stars at its edges, where the dust lanes and shapes melt into the inky background. Numerous nearby stars and galaxies are visible as small smudges in the surrounding sky, and the brightest stars are dazzlingly prominent towards the bottom left of the image. ESO 121-6 is a galaxy with patchy, loosely wound arms and …

28 January 2013: The further away you look, the further back in time you see. Astronomers use this fact to study the evolution of the Universe by looking at nearby and more distant galaxies and comparing their features. Hubble is particularly well suited for this type of work because of its extremely high resolution and its position above the atmosphere. This has allowed it to detect many of the most distant galaxies known, as well as making detailed images of faraway objects. Comparing galaxies in the distant past with those around us today, astronomers have noticed that the nearby galaxies are far quieter and calmer than their distant brethren, seen earlier in their lives. Nearby galaxies (although not the Milky Way) are often large, elliptical galaxies with little or no ongoing star formation, and their stars tend to be elderly and red in colour. These galaxies, in astronomers' language, are "red and dead". …

21 January 2013: Globular clusters are roughly spherical collections of extremely old stars, and around 150 of them are scattered around our galaxy. Hubble is one of the best telescopes for studying these, as its extremely high resolution lets astronomers see individual stars, even in the crowded core. The clusters all look very similar, and in Hubble’s images it can be quite hard to tell them apart – and they all look much like NGC 411, pictured here. And yet appearances can be deceptive: NGC 411 is in fact not a globular cluster, and its stars are not old. It isn’t even in the Milky Way. NGC 411 is classified as an open cluster. Less tightly bound than a globular cluster, the stars in open clusters tend to drift apart over time as they age, whereas globulars have survived for well over 10 billion years of galactic history. NGC 411 is a relative …

14 January 2013: A busy patch of space has been captured in this image from the NASA/ESA Hubble Space Telescope. Scattered with many nearby stars, the field also has numerous galaxies in the background. Located on the border of Triangulum Australe (The Southern Triangle) and Norma (The Carpenter’s Square), this field covers part of the Norma Cluster (Abell 3627) as well as a dense area of our own galaxy, the Milky Way. The Norma Cluster is the closest massive galaxy cluster to the Milky Way, and lies about 220 million light-years away. The enormous mass concentrated here, and the consequent gravitational attraction, mean that this region of space is known to astronomers as the Great Attractor, and it dominates our region of the Universe. The largest galaxy visible in this image is ESO 137-002, a spiral galaxy seen edge on. In this image from Hubble, we see large regions of dust across the …

7 January 2013: The constellation of Ursa Major (The Great Bear) is home to Messier 101, the Pinwheel Galaxy. One of the biggest and brightest spiral galaxies in the night sky, Messier 101 is also the subject of one of Hubble's most famous images (heic0602). Like the Milky Way, Messier 101 is not alone, with smaller dwarf galaxies in its neighbourhood. NGC 5477, one of these dwarf galaxies in the Messier 101 group, is the subject of this image from the NASA/ESA Hubble Space Telescope. Without obvious structure, but with visible signs of ongoing starbirth, NGC 5477 looks much like an archetypal dwarf irregular galaxy. The bright nebulae that extend across much of the galaxy are clouds of glowing hydrogen gas in which new stars are forming. These glow pinkish red in real life, although the selection of green and infrared filters through which this image was taken makes them appear almost white. …

31 December 2012: The Universe loves to fool our eyes, giving the impression that celestial objects are located at the same distance from Earth. A good example can be seen in this spectacular image produced by the NASA/ESA Hubble Space Telescope. The galaxies NGC 5011B and NGC 5011C are imaged against a starry background. Located in the constellation of Centaurus, the nature of these galaxies has puzzled astronomers. NGC 5011B (on the right) is a spiral galaxy belonging to the Centaurus Cluster of galaxies lying 156 million light-years away from the Earth. Long considered part of the faraway cluster of galaxies as well, NGC 5011C (the bluish galaxy at the centre of the image) is a peculiar object, with the faintness typical of a nearby dwarf galaxy, alongside the size of an early-type spiral. Astronomers were curious about the appearance of NGC 5011C. If the two galaxies were at roughly the same distance …

24 December 2012: The NASA/ESA Hubble Space Telescope provides us this week with a spectacular image of the bright star-forming ring that surrounds the heart of the barred spiral galaxy NGC 1097. In this image, the larger-scale structure of the galaxy is barely visible: its comparatively dim spiral arms, which surround its heart in a loose embrace, reach out beyond the edges of this frame. This face-on galaxy, lying 45 million light-years away from Earth in the southern constellation of Fornax (The Furnace), is particularly attractive for astronomers. NGC 1097 is a Seyfert galaxy. Lurking at the very centre of the galaxy, a supermassive black hole 100 million times the mass of our Sun is gradually sucking in the matter around it. The area immediately around the black hole shines powerfully with radiation coming from the material falling in. The distinctive ring around the black hole is bursting with new star formation due …

17 December 2012: Like finding a silver needle in the haystack of space, the NASA/ESA Hubble Space Telescope has produced this beautiful image of the spiral galaxy IC 2233, one of the flattest galaxies known. Typical spiral galaxies like the Milky Way are usually made up of three principal visible components: the disc where the spiral arms and most of the gas and dust is concentrated; the halo, a rough and sparse sphere around the disc that contains little gas, dust or star formation; and the central bulge at the heart of the disc, which is formed by a large concentration of ancient stars surrounding the Galactic Centre. However, IC 2233 is far from being typical. This object is a prime example of a super-thin galaxy, where the galaxy’s diameter is at least ten times larger than the thickness. These galaxies consist of a simple disc of stars when seen edge on. This …

10 December 2012: Located in a relatively vacant region of space about 4200 light-years away and difficult to see using an amateur telescope, the lonesome planetary nebula NGC 7354 is often overlooked. However, thanks to this image captured by the NASA/ESA Hubble Space Telescope we are able to see this brilliant ball of smoky light in spectacular detail. Just as shooting stars are not actually stars and lava lamps do not actually contain lava, planetary nebulae have nothing to do with planets. The name was coined by Sir William Herschel because when he first viewed a planetary nebula through a telescope, he could only identify a hazy smoky sphere, similar to gaseous planets such as Uranus. The name has stuck even though modern telescopes make it obvious that these objects are not planets at all, but the glowing gassy outer layers thrown off by a hot dying star. It is believed that winds …

3 December 2012: The brilliant cascade of stars through the middle of this image is the galaxy ESO 318-13 as seen by the NASA/ESA Hubble Space Telescope. Despite being located millions of light-years from Earth, the stars captured in this image are so bright and clear you could almost attempt to count them. Although ESO 318-13 is the main event in this image, it is sandwiched between a vast collection of bright celestial objects. Several stars near and far dazzle in comparison to the neat dusting contained within the galaxy. One that particularly stands out is located near the centre of the image, and looks like an extremely bright star located within the galaxy. This is, however, a trick of perspective. The star is located in the Milky Way, our own galaxy, and it shines so brightly because it is so much closer to us than ESO 318-13. There are also a number …

26 November 2012: The NASA/ESA Hubble Space Telescope provides us this week with an impressive image of the irregular galaxy NGC 5253. NGC 5253 is one of the nearest of the known Blue Compact Dwarf (BCD) galaxies, and is located at a distance of about 12 million light-years from Earth in the southern constellation of Centaurus. The most characteristic signature of these galaxies is that they harbour very active star-formation regions. This is in spite of their low dust content and comparative lack of elements heavier than hydrogen and helium, which are usually the basic ingredients for star formation. These galaxies contain molecular clouds that are quite similar to the pristine clouds that formed the first stars in the early Universe, which were devoid of dust and heavier elements. Hence, astronomers consider the BCD galaxies to be an ideal testbed for better understanding the primordial star-forming process. NGC 5253 does contain some dust …

19 November 2012: The NASA/ESA Hubble Space Telescope has spotted the spiral galaxy ESO 499-G37, seen here against a backdrop of distant galaxies, scattered with nearby stars. The galaxy is viewed from an angle, allowing Hubble to  reveal its spiral nature clearly. The faint, loose spiral arms can be distinguished as bluish features swirling around the galaxy’s nucleus. This blue tinge emanates from the hot, young stars located in the spiral arms. The arms of a spiral galaxy have large amounts of gas and dust, and are often areas where new stars are constantly forming. The galaxy’s most characteristic feature is a bright elongated nucleus. The bulging central core usually contains the highest density of stars in the galaxy, where typically a large group of comparatively cool old stars are packed in this compact, spheroidal region. One feature common to many spiral galaxies is the presence of a bar running across the centre …