Researchers at the European Space Agency (ESA) have captured some of the most striking images ever of the galaxy M81 and the supermassive black hole it contains. ESA's XMM-Newton X-ray Space Observatory took the ultraviolet pictures using the spacecraft's Optical Monitor telescope. The images reveal stellar nurseries scattered throughout the galaxy, but these hot, bluish regions are particularly visible at M81's core.
"M81 contains many short-lived stars, and these are best studied in ultraviolet light," explains lead scientist Alice Breeveld of University College, London. "The UV images pick out intense regions of star formation." Cooler areas, where the stars are older, appear red. The bright red stars in the image are not located in M81 at all but rather in our own Milky Way galaxy.
M81 is located approximately 12 million light-years from Earth. Because the galaxy is so luminous, even an amateur telescope can readily pick it out in the northern hemisphere in the Ursa Major constellation. Its current shape and intense star formation are probably due to a run-in with a celestial neighbor, Breeveld says. "We believe that a collision with the nearby galaxy M82 could have led to the formation of the spiral arm structure. The high densities and pressures involved would have triggered the star formation."