Messier 82 is a starburst galaxy with a superwind. In fact, through supernova explosions and powerful winds from massive stars, the burst of star formation in M82 is driving a prodigious outflow. Evidence for the superwind from the galaxy's central regions is clear in the sharp telescopic portrait . The composite image includes 33 hours of narrowband data, highlighting emission from long outflow filaments of atomic hydrogen gas in reddish hues. Some of the gas in the superwind, enriched in heavy elements forged in the massive stars , will eventually escape into intergalactic space . Triggered by a close encounter with nearby large galaxy M81 , the furious burst of star formation in M82 should last about 100 million years or so. Also known as the Cigar Galaxy for its elongated visual appearance, M82 is about 30,000 light-years across. It lies 12 million light-years away near the northern boundary of Ursa Major . from NASA https://ift.tt/8LaG54J
If you live in the northern hemisphere , you may have learned how to locate the North Star, Polaris , in the night sky. It can be used to find north, and it approximately marks the northern celestial pole . If you live in the southern hemisphere, there is no bright star marking the southern celestial pole, but the Southern Cross can be used to find south. The featured image was taken in Padre Bernardo ( GO ), Brazil . It shows the apparent motion of the stars around the apparently empty southern celestial pole over 2 hours, on August 20, 2018. Each star takes about 24 hours to make a complete turn around the pole in the sky. Padre Bernardo is located in the Cerrado region, a tropical savanna that occupies most of central Brazil and supports rich biodiversity . The barren branch that apparently supports this sky wheel of rotating stars is a common sight there in the dry season during the southern winter. from NASA https://ift.tt/F5zARth