This view of the Andromeda galaxy from the Herschel space observatory shows relatively cool lanes of forming stars. Herschel was sensitive to the far-infrared light from cool dust mixed in with the gas where stars are born. This image reveals some of the very coldest dust in the galaxy (colored red here) that is only a few tens of degrees above absolute zero. Warmer regions such as the densely populated central bulge, home to older stars, appear as blue. Star-formation zones are in the spiral arms with several concentric rings interspersed with dark gaps where star formation is absent.
Andromeda (aka M31) is the nearest major galaxy to our own Milky Way about 2.5 million light-years away. Herschel was a European Space Agency mission active from 2009 to 2013.
Image Credit: ESA
Andromeda Galaxy (aka M31) is just next door as large galaxies go, only about 2.5 million light-years. So close and spanning some 260,000 light-years, it took 11 images from the Galaxy Evolution Explorer (GALEX) satellite’s telescope to produce this portrait of the spiral galaxy in ultraviolet light. While its spiral arms stand out in visible light images, they look like rings in UV because the image is dominated by light from hot, young, massive stars. As sites of intense star formation, the rings have been interpreted as evidence Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago.
Image Credit: NASA
This mosaic of M31 merges 330 individual images taken by the Ultraviolet/Optical Telescope aboard the Swift spacecraft. It is the highest-resolution image of the galaxy ever recorded in the ultraviolet. Also known as the Andromeda Galaxy, M31 is more than 220,000 light-years across and lies 2.5 million light-years away. On a clear, dark night, the galaxy is faintly visible as a misty patch to the naked eye.
The irregular shape of the image results when the more than 300 images were assembled to make the final image.
There are three instruments on Swift—a UV telescope, an X-ray telescope, and the Burst Alert Telescope which serves as the gamma ray burst detector for the spacecraft. I contributed to the design of the ultra-quiet regulators powering the detector blocks in the BAT.
Image Credit: NASA /Swift / Stefan Immler (GSFC) and Erin Grand (UMCP)