NGC 3185


potw1326Spiral galaxy NGC 3185 is about 80 million light-years away from us in the constellation of Leo (the Lion). The galaxy’s spiral arms swirl outward from the center of the galaxy toward the rim where they join a blue disk of young stars. At the galactic center of is a small but very bright nucleus containing a supermassive black hole. Supermassive black holes have masses many thousands of times that of our Sun, and they become active as matter falls towards them. When this happens the black hole lights up, sending away streams of particles and radiation at almost the speed of light.

ML_GalaxyNGC 3185 is a member of a four-galaxy group known as Hickson 44. NGC 3190 is a somewhat more famous member of the group. Apple used a blue-tinted image of it as the default wallpaper for its Mountain Lion operating system.

Image Credits: NASA, Apple

A Stellar Death Spiral


Roughly 290 million years ago, a star more or less like the Sun got too close to the central black hole of its galaxy. Intense tides tore the star apart and the resulting outburst of visible, ultraviolet and X-ray light first reached Earth in 2014. Observations from the Swift satellite have mapped out how and where these different wavelengths were produced as the shattered star’s debris circled the black hole. This animation illustrates how debris from a tidally disrupted star collided with itself, creating shock waves that emit ultraviolet and visible light. According to the Swift observations, that debris then took about a month to fall back to the black hole, where they produced changes in its X-ray emission that correlated with the earlier UV and visible light bursts.

Video Credit: NASA