Matt Jones' Random Acts of Verbiage

Welcome to this week’s Space Saturday! This week I bring you M64, the Black Eye Galaxy.

Credit: NASA and The Hubble Heritage Team (AURA/STScI) (Source)

This is the Black Eye spiral galaxy (also known as M64 or NGC 4826). It resides some 17 million light years away in the constellation Coma Berenices. Aside from being a beautiful sight to look at, it has an interesting feature: its main, inner structure (all he visible stars, about 3000 light years in radius) rotates counter to the extended portion (the interstellar gas, an additional 40,000 light years out). The beautiful structure is caused by dust bands which have given rise to the Black Eye name. The area where the two regions of opposite movement meet make for an interesting life:

Active formation of new stars is occurring in the shear region where the oppositely rotating gases collide, are compressed, and contract. Particularly noticeable in the image are hot, blue young stars that have just formed, along with pink clouds of glowing hydrogen gas that fluoresce when exposed to ultraviolet light from newly formed stars.

It is believed that the two regions are rotating oppositely because of a collision between M64 and a smaller satellite galaxy some hundreds of millions of years (maybe even a billion years) ago. Beautiful and interesting!

If you enjoy astronomy pictures, be sure to check out my Space Saturday Archive!

Resources:
HubbleSite - Dust Band Around the Nucleus of “Black Eye Galaxy” M64
Wikipedia - M64: The Black Eye Galaxy
SEDS - Messier 64