Andromeda Galaxy Gets Best UV Photo Ever

In a new study of the M31 galaxy, our closest galactic neighbor from the Andromeda Constellation, the American space agency's Swift satellite managed to snap the most complex and detailed image of its ultraviolet sources. Experts say that some 20,000 of them are visible in the new, high-resolution picture, and that many blue, young stars were also revealed when analyzing light emitted by the galaxy at these wavelengths. Andromeda is some 2.5 million light-years away from the Milky Way.

“Swift reveals about 20,000 ultraviolet sources in M31, especially hot, young stars and dense star clusters. Of particular importance is that we have covered the galaxy in three ultraviolet filters. That will let us study M31's star-formation processes in much greater detail than previously possible,” Swift team research scientist Stefan Immler, from the NASA-operated Goddard Space Flight Center, in Greenbelt, Maryland, says of the new effort.

According to current astronomical theories, the Milky Way and Andromeda are on a collision course with each other, and will meet up in a few billion years. While our galaxy is considered to be massive at a diameter of about 100,000 light-years, M31 is some 220,000 light-years across. It is visible to the naked eye when no light pollution is in sight, as a hazy patch of light on the night sky. When viewed through a large telescope, it is approximately six times larger than a full Moon. Only the brightest parts of this central region are visible with the unaided eye, Space reports.

“The bulge is smoother and redder because it's full of older and cooler stars. Very few new stars form here because most of the materials needed to make them have been depleted,” Immler adds. “After ten weeks of processing that immense amount of data, I'm extremely proud of this new view of M31,” University of Maryland in College Park undergraduate student Erin Grand, who has collaborated with Immler this summer, pinpoints. Together, they assembled some 85 gigabytes of images into a single view.