A galaxy with lots to see

While it may appear unassuming at first glance, just another spiral galaxy among thousands in the Universe, this subject of the ESA/Hubble Picture of the Week has plenty to study. NGC 7456 is its name, located over 51 million light-years away in the constellation Grus (the Crane).

In this image we see in fine detail the patchy spiral arms of this galaxy, followed by clumps of dark, obscuring dust. Blossoms of glowing pink are rich reservoirs of gas where new stars are forming, illuminating the clouds around them and causing the gas to emit this tell-tale red light. The Hubble programme which collected this data is focused on stellar activity just like this, tracking new stars, clouds of hydrogen and star clusters to learn how the galaxy has evolved through time.

Hubble, with its ability to capture visible, ultraviolet and some infrared light, is not the only observatory focused on NGC 7456. ESA’s XMM-Newton satellite has imaged X-rays from the galaxy on multiple occasions, discovering a number of so-called ultraluminous X-ray sources. These small, compact objects emit terrifically powerful X-rays, much more than would be expected for their size. Astronomers are still trying to pin down what powers these extreme objects, and NGC 7456 contributes a few more examples.

On top of that, the region around the galaxy’s supermassive black hole is spectacularly bright and energetic, making NGC 7456 an active galaxy. Whether looking at its core or its outskirts, at visible light or X-rays, this galaxy has something interesting to show!

[Image Description: A spiral galaxy. It shines brightly at the centre, and most of its disc also glows in warm colours. Its two spiral arms, which wind outwards from the centre, are made up mostly of large patches of bright blue specks. They also contain thin, reddish clouds of dust, and bright pink bubbles of glowing gas, where stars are forming. Distant galaxies can be seen around the galaxy as small orange spots, on a dark background.]