Space photo of the week: Hubble hunts a stellar ‘imposter’ hiding in the Great Bear
What it is: The spiral galaxy UGC 5460
Where it is: 60 million light-years away in the constellation Ursa Major
When it was shared: Feb. 21, 2025
Why it’s so special: This stunning new image of a spiral galaxy — and a very bright star above it — was recently captured by the Hubble Space Telescope. The image shows the galaxy’s central bar of stars, along with its spiral arms and young, blue star clusters. The top-left of the image, meanwhile, is dominated by a star that’s just 577 light-years away in the Milky Way.
This galaxy has hosted two significant supernova explosions in the last 14 years. Such events are landmarks for astronomers and are the final, destructive stage for some massive stars. A supernova explosion can briefly have the power of up to 100 billion stars and temporarily outshine their host galaxies.
Supernovae play a vital role in spreading heavy elements around interstellar space, which in turn sparks the formation of new stars.
Related: The 10 biggest explosions in history
These stellar explosions may be inevitable for some classes of stars, but they can play out in wildly different ways — which scientists suspect is the case for the two recent supernovas that erupted in this picturesque spiral galaxy.
For example, in 2015, astronomers watched the star SN 2015 explode as a “core-collapse” supernova, when the massive star consumed its nuclear fuel and collapsed under gravity, causing its outer layers to be ejected into UGC 5460. This explosion led astronomers to take the new image of the galaxy, as they wanted to find out how a supernova’s shock wave interacts with the interstellar gas surrounding it.
An earlier supernova explosion in 2011, meanwhile, called SN 2011ht, initially appeared to be a core collapse. However, astronomers suspect that it may be a so-called “luminous blue variable” — a rare kind of massive star that outbursts like a supernova but leaves the star intact. Hubble is now looking for the surviving star at the explosion site.
This detailed image of UGC 5460 from Hubble’s Wide Field Camera combines data from the ultraviolet, near-infrared and visible light parts of the spectrum.
The galaxy is found close to the stars Merak and Dubhe on the outside of the bowl, in the shape of the Big Dipper/Plough asterism in the night sky, though it is too dim to see with anything other than large professional astronomy telescopes.
For more sublime space images, check out our Space Photo of the Week archives.
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