Lopsided M96

A galactic maelstromThis is Messier 96, a spiral galaxy a bit more than 35 million light-years away in the constellation of Leo (The Lion). It is roughly the same mass and size as the Milky Way, but unlike our more or less symmetrical galaxy, M96 is lopsided. Its dust and gas are unevenly spread throughout its weak spiral arms, and its core is not exactly at the apparent galactic center. Its arms are also asymmetrical, perhaps because of the gravitational pull of other galaxies within the same group as Messier 96.

Image Credit: ESA / NASA

A Big Sibling for the Milky Way

NGC 6744 is similar to our home galaxy, but it’s about 200,000 light-years in diameter, about twice the size of our galaxy. Like the Milky Way, NGC 6744 has a prominent central core packed with old yellow stars. Its dusty spiral arms glow in shades of pink and blue; while the blue sites are full of young star clusters, the pink ones are regions of active star formation, indicating that the galaxy is still very lively.

Image Credit: ESA / NASA

A Home for Variable Stars

NGC 4603NGC 4603 is a spiral galaxy located a bit more than 100 million light years away in the constellation Centaurus. It’s a pure spiral galaxy with relatively loosely wound arms. During 1999, this galaxy was the subject of an extended study using the Hubble Space Telescope to locate Cepheid variable stars. Over 40 were found, and the measurement of their periodicities gave a net distance estimate of 108.7, +5.5,−4.9 million light years. That was consistent with the distance estimate determined through redshift measurements. As of the date of that study, NGC 4603 was the most distant galaxy for which a distance estimate had been made using Cepheid variable.

Image Credit: NASA