Picture of the Week

9 June 2025: This serene spiral galaxy hides a cataclysmic past. The galaxy IC 758, shown here in today’s NASA/ESA Hubble Space Telescope Picture of the Week, is situated 60 million light-years away in the constellation Ursa Major. In this Hubble image captured in 2023, IC 758 appears peaceful, its soft blue spiral arms curving gently around its hazy barred centre. But in 1999, astronomers spotted a powerful explosion in this galaxy: the supernova SN 1999bg. SN 1999bg marked the dramatic end of a star far more massive than the Sun. It’s not yet known how massive this star was before it exploded. Researchers will use these Hubble observations to measure the masses of stars in SN 1999bg’s neighbourhood, which will help them estimate the mass of the star that went supernova. The Hubble data may also reveal whether SN 1999bg’s progenitor star had a companion, which would give additional clues about the …

2 June 2025: A galaxy ablaze with young stars is the subject of today’s NASA/ESA Hubble Space Telescope Picture of the Week. This galaxy is called NGC 685 and is situated about 64 million light-years away in the constellation Eridanus (The River). NGC 685 is classified as a barred spiral because its feathery spiral arms sprout from the ends of a bar of stars at the galaxy’s centre. The Milky Way is also a barred spiral, but our galaxy is a little less than twice the size of NGC 685. Astronomers used Hubble to study NGC 685 for two observing programmes, both of which focus on star formation. It’s no surprise that NGC 685 was chosen for these programmes: numerous patches of young blue stars highlight the galaxy’s spiral arms. Many of these star clusters are cocooned in pink gas clouds, which are called H II (pronounced ‘H-two’) regions. An H II region …

26 May 2025: A single member of a galaxy pair takes centre stage in this NASA/ESA Hubble Space Telescope Picture of the Week. This beautiful spiral galaxy is NGC 3507, which is situated about 46 million light-years away in the constellation Leo. NGC 3507 is classified as a barred spiral because the galaxy’s sweeping spiral arms emerge from the ends of a central bar of stars rather than the central point of the galaxy. Though pictured solo here, NGC 3507 actually travels the Universe with a galactic partner named NGC 3501 that is located outside the frame. NGC 3501 was featured in a previous Picture of the Week. While NGC 3507 is a quintessential galactic pinwheel, its partner resembles a streak of quicksilver across the sky. Despite looking completely different, both are spiral galaxies, simply seen from different angles. For galaxies that are just a few tens of millions of light-years away, like …

19 May 2025: The stately and inclined spiral galaxy NGC 3511 is the subject of this NASA/ESA Hubble Space Telescope Picture of the Week. The galaxy is located 43 million light-years away in the constellation Crater (The Cup). From Hubble’s vantage point in orbit around Earth, NGC 3511 is tilted by about 70 degrees, intermediate between face-on galaxies that display picture-perfect spiral arms and edge-on galaxies that reveal only their dense, flattened discs. Astronomers are studying NGC 3511 as part of a survey of the star formation cycle in nearby galaxies. For this observing programme, Hubble will record the appearance of 55 local galaxies using five filters that allow in different wavelengths, or colours, of light. One of these filters allows only a specific wavelength of red light to pass through. Giant clouds of hydrogen gas glow in this red colour when energised by ultraviolet light from hot young stars. As this image …

5 May 2025: The spiral galaxy NGC 3596 is on display in this NASA/ESA Hubble Space Telescope Picture of the Week, which incorporates six different wavelengths of light. NGC 3596 is situated 90 million light-years from Earth in the constellation Leo. The galaxy was discovered in 1784 by astronomer William Herschel, the namesake of ESA’s Herschel Space Observatory. NGC 3596 appears almost perfectly face-on when viewed from Earth, showcasing the galaxy’s neatly wound spiral arms. The bright arms mark where the galaxy’s stars, gas and dust are concentrated. Star formation is also most active in a galaxy’s spiral arms, as shown by the brilliant pink star-forming regions and young blue stars tracing NGC 3596’s arms in this image. What causes these spiral arms to form? It’s a surprisingly difficult question to answer, partly because of the remarkable diversity of spiral galaxies. Some have clear spiral arms, while others have patchy, feathery arms. Some …

28 April 2025: A beautiful but skewed spiral galaxy dazzles in today’s NASA/ESA Hubble Space Telescope Picture of the Week. This galaxy, called Arp 184 or NGC 1961, sits about 190 million light-years away from Earth in the constellation Camelopardalis (The Giraffe). The name Arp 184 comes from the Atlas of Peculiar Galaxies, which was compiled by astronomer Halton Arp in 1966. The 338 galaxies in the atlas are oddly shaped, tending to be neither entirely elliptical nor entirely spiral-shaped. Many of the galaxies are in the process of interacting with other galaxies, while others are dwarf galaxies without well-defined structures. Arp 184 earned its spot in the catalogue thanks to its single broad, star-speckled spiral arm that appears to stretch toward us. The galaxy’s far side sports a few wisps of gas and stars but lacks a similarly impressive spiral arm. This Hubble image combines data from three Snapshot observing programmes, which …

21 April 2025: As part of ESA/Hubble’s 35th anniversary celebrations, a new image series has been shared throughout April to revisit stunning Hubble targets that were previously released. New images of NGC 346, the Sombrero Galaxy, and the Eagle Nebula have already been published. Now, ESA/Hubble is revisiting the star cluster Messier 72 (M72) with new data and image processing techniques. M72 is a particularly special target because it was the first image ever published in the ESA/Hubble Picture of the Week series, on 22 April 2010. For fifteen years, the ESA/Hubble team has been publishing a new Hubble image every Monday for everyone to enjoy. This has resulted in nearly 800 images being added to the vast Hubble image archive over the years. M72 is a collection of stars, formally known as a globular cluster, located in the constellation Aquarius roughly 50 000 light years from Earth. The intense gravitational attraction between …

14 April 2025: Today’s rather aquatic-themed NASA/ESA Hubble Space Telescope Picture of the Week features the spiral galaxy Messier 77, also known as the Squid Galaxy, which sits 45 million light-years away in the constellation Cetus (The Whale). The designation Messier 77 comes from the galaxy’s place in the famous catalogue compiled by the French astronomer Charles Messier. Another French astronomer, Pierre Méchain, discovered the galaxy in 1780. Both Messier and Méchain were comet hunters who catalogued nebulous objects that could be mistaken for comets. Messier, Méchain, and other astronomers of their time mistook the Squid Galaxy for either a spiral nebula or a star cluster. This mischaracterisation isn’t surprising. More than a century would pass between the discovery of the Squid Galaxy and the realisation that the ‘spiral nebulae’ scattered across the sky were not part of our galaxy and were in fact separate galaxies millions of light-years away. The Squid Galaxy’s …

31 March 2025: This NASA/ESA Hubble Space Telescope Picture of the Week features the picturesque spiral galaxy NGC 4941, which lies about 67 million light-years from Earth in the constellation Virgo (The Maiden). Because this galaxy is nearby, cosmically speaking, Hubble’s keen instruments are able to pick out exquisite details such as individual star clusters and filamentary clouds of gas and dust. The data used to construct this image were collected as part of an observing programme that investigates the star formation and stellar feedback cycle in nearby galaxies. As stars form in dense, cold clumps of gas, they begin to influence their surroundings. Stars heat and stir up the gas clouds in which they are born through winds, starlight, and — eventually, for massive stars — by exploding as supernovae. These processes are collectively called stellar feedback, and they impact the rate at which a galaxy can form new stars. As it …

24 March 2025: The subject of today’s NASA/ESA Hubble Space Telescope Picture of the Week is the stunning spiral galaxy NGC 5530. NGC 5530 is situated 40 million light-years away in the constellation Lupus (The Wolf). This galaxy is classified as a ‘flocculent’ spiral, meaning that its spiral arms are patchy and indistinct. While some galaxies have extraordinarily bright centres where they host a feasting supermassive black hole, the bright source near the centre of NGC 5530 is not an active black hole but instead a star within our own galaxy, only 10 thousand light-years from Earth. This chance alignment gives the appearance that the star is at the dense heart of NGC 5530. If you had pointed a backyard telescope at NGC 5530 on the evening of 13 September 2007, you would have seen another bright point of light adorning the galaxy. That night, Australian amateur astronomer Robert Evans discovered a supernova, …

10 March 2025: This NASA/ESA Hubble Space Telescope Picture of the Week features a sparkling spiral galaxy paired with a prominent star, both in the constellation Virgo. While the galaxy and the star appear to be close to one another, even overlapping, they’re actually a great distance apart. The star, which is marked with four long diffraction spikes, is in our own galaxy. It’s just 7109 light-years away from Earth. The galaxy, which is named NGC 4900, lies about 45 million light-years from Earth. This image combines data from two of Hubble’s instruments: the Advanced Camera for Surveys, which was installed in 2002 and is still in operation today, and the older Wide Field and Planetary Camera 2, which was in use from 1993 to 2009. The data used here were taken more than 20 years apart for two different observing programmes — a real testament to Hubble’s long scientific lifetime! Both programmes …

3 March 2025: This vibrant spiral galaxy and the subject of today’s NASA/ESA Hubble Space Telescope Picture of the Week is NGC 5042, which resides about 48 million light-years from Earth in the constellation Hydra (the water snake). The galaxy nicely fills the frame of this Hubble image, with a single Milky Way star marked by cross-shaped diffraction spikes attempting to blend in with the bright stars along the galaxy’s edge. Hubble observed NGC 5042 in six wavelength bands from the ultraviolet to the infrared to create this multicoloured portrait. The galaxy’s cream-coloured centre is packed with ancient stars, and the galaxy’s spiral arms are decorated with patches of young blue stars. The elongated yellow-orange objects that are scattered around the image are background galaxies far more distant than NGC 5042. Perhaps NGC 5042’s most striking feature is its collection of brilliant pink gas clouds that are studded throughout its spiral arms. These …

17 February 2025: The sparkling spiral galaxy gracing this NASA/ESA Hubble Space Telescope Picture of the Week is UGC 5460, which sits about 60 million light-years away in the constellation Ursa Major. This image combines four different wavelengths of light to reveal UGC 5460’s central bar of stars, winding spiral arms and bright blue star clusters. Also captured in the upper left-hand corner of this image is a far closer object: a star just 577 light-years away in our own galaxy. UGC 5460 has hosted two recent supernovae named SN 2011ht and SN 2015as. It’s because of these two stellar explosions that Hubble targeted this galaxy, collecting data for three observing programmes that aim to study various kinds of supernovae. SN 2015as was what’s known as a core-collapse supernova: a cataclysmic explosion that happens when the core of a star far more massive than the Sun runs out of fuel and collapses under …

3 February 2025: A supernova and its host galaxy are the subject of today’s NASA/ESA Hubble Space Telescope Picture of the Week. The galaxy in question is LEDA 132905, which is situated in the constellation Sculptor. Even at over 400 million light-years away, LEDA 132905’s spiral structure is faintly visible, as are patches of bright blue stars. The bright white dot directly in the centre of the image, between the bright centre of the galaxy and its faint left edge, is a supernova named SN 2022abvt. SN 2022abvt was discovered in late 2022, and Hubble observed the explosion about two months later. This image was constructed from data collected to study Type Ia supernovae, which occur when the exposed core of a dead star ignites in a sudden, destructive burst of nuclear fusion. Researchers are interested in this type of supernova because they can be used to measure precise distances to other galaxies. …

6 January 2025: This week’s NASA/ESA Hubble Space Telescope Picture of the Week shows a tiny patch of sky in the constellation Hydra. The stars and galaxies depicted here span a mind-bending range of distances. Nearest to us in this image are stars within our own Milky Way galaxy, which are marked by diffraction spikes. The bright star that sits just at the edge of the prominent bluish galaxy is only 3230 light-years away, as measured by ESA's Gaia space observatory. Behind this star is a galaxy named LEDA 803211. At 622 million light-years distant, this galaxy is close enough that its bright galactic nucleus is clearly visible, as are numerous star clusters scattered around its patchy disc. Many of the more distant galaxies in this frame appear star-like, with no discernible structure, but without the diffraction spikes of a star in our galaxy. Of all the galaxies in this frame, one pair …

30 December 2024: This NASA/ESA Hubble Space Telescope Picture of the Week features the galaxy LEDA 22057, which is located about 650 million light-years away in the constellation Gemini. Like the subject of last week’s Picture of the Week, LEDA 22057 is the site of a supernova explosion. This particular supernova, named SN 2024PI, was discovered by an automated survey in January 2024. The survey covers the entire northern half of the night sky every two days and has catalogued more than 10 000 supernovae. The supernova is visible in this image: located just down and to the right of the galactic nucleus, the pale blue dot of SN 2024PI stands out against the galaxy’s ghostly spiral arms. This image was taken about a month and a half after the supernova was discovered, so the supernova is seen here many times fainter than its maximum brilliance. SN 2024PI is classified as a Type …

23 December 2024: The subject of this NASA/ESA Hubble Space Telescope Picture of the Week is the spiral galaxy NGC 337, located about 60 million light-years away in the constellation Cetus (The Whale). This image combines observations made at two wavelengths, highlighting the galaxy’s golden centre and blue outskirts. The golden central glow comes from older stars, while the sparkling blue edges get their colour from young stars. If Hubble had observed NGC 337 about a decade ago, the telescope would have spotted something remarkable among the hot blue stars along the galaxy’s edge: a brilliant supernova. The supernova, named SN 2014cx, is remarkable for having been discovered nearly simultaneously in two vastly different ways: by a prolific supernova hunter, Koichi Itagaki, and by the All Sky Automated Survey for SuperNovae (ASAS-SN). ASAS-SN is a worldwide network of robotic telescopes that scans the sky for sudden events like supernovae. Researchers have determined that …

16 December 2024: Featured in this NASA/ESA Hubble Space Telescope Picture of the Week is the spiral galaxy NGC 2566, which sits 76 million light-years away in the constellation Puppis. A prominent bar of stars stretches across the centre of this galaxy, and spiral arms emerge from each end of the bar. Because NGC 2566 appears tilted from our perspective, its disc takes on an almond shape, giving the galaxy the appearance of a cosmic eye. As NGC 2566 gazes at us, astronomers gaze right back, using Hubble to survey the galaxy’s star clusters and star-forming regions. The Hubble data are especially valuable for studying stars that are just a few million years old; these stars are bright at the ultraviolet and visible wavelengths to which Hubble is sensitive. Using these data, researchers will measure the ages of NGC 2566’s stars, helping to piece together the timeline of the galaxy’s star formation and …

9 December 2024: Today’s NASA/ESA Hubble Space Telescope Picture of the Week features the glorious spiral galaxy NGC 5643, which is located roughly 40 million light-years away in the constellation Lupus. NGC 5643 is what’s known as a grand design spiral, referring to how the galaxy’s two large, winding spiral arms are clear to see. The spiral arms are defined by bright blue stars, lacy reddish-brown dust clouds and pink star-forming regions. As fascinating as the galaxy appears at visible wavelengths, some of NGC 5643’s most interesting features are invisible to the human eye. Ultraviolet and X-ray images and spectra of NGC 5643 show that the galaxy hosts an active galactic nucleus: an especially bright galactic core powered by a feasting supermassive black hole. When a supermassive black hole ensnares gas from its surroundings, the gas collects in a disc that heats up to hundreds of thousands of degrees. The superheated gas shines …

2 December 2024: The subject of this NASA/ESA Hubble Space Telescope Picture of the Week is NGC 1637, a spiral galaxy located 38 million light-years from Earth in the constellation Eridanus. This image comes from an observing programme dedicated to studying star formation in nearby galaxies. Stars form in cold, dusty gas clouds that collapse under their own gravity. As young stars grow, they heat their nurseries through starlight, winds, and powerful outflows. Together, these factors play a role in controlling the rate at which future generations of stars form. Evidence of star formation is scattered all around NGC 1637, if you know where to look. The galaxy’s spiral arms are dotted with what appear to be pink clouds, many of which are accompanied by bright blue stars. The pinkish colour comes from hydrogen atoms that have been excited by ultraviolet light from young, massive stars. This contrasts with the warm yellow glow …