Image Credit & Copyright: NASA/ESA Hubble Space Telescope.
I love this image because the information really packs some wow factor and it shows that there’s beauty in information. This may not be the prettiest of space pictures but for those of you who take the time to read this, it is beautiful indeed.
This image, captured by the Hubble Space Telescope shows us a close up view of a messy collection of galaxies. This collection is known as the Coma Cluster of galaxies (Abell 1656) and it contains more than 1,000 cataloged galaxies. That, in and of itself would be mind boggling but this cluster has a partner in time; the Leo Cluster of galaxies (Abell 1367) which contains another 100 or so galaxies. Combined, this mass is known as the Coma Supercluster and it spans 20 million light years and lies between Leo and Bootes. If you could see these galaxies with the unaided eye, it would stretch nearly 10 Full Moon diameters on the night sky. With well over a thousand galaxies and a truly uncountable number of stars, this region is a wonder to learn about. But we’re just beginning.
Most of the galaxies in this region are elliptical galaxies with only a smattering of spirals to count. Elliptical galaxies are massive, balls of stars that were likely formed by collisions of two or more spiral galaxies that, when all was said and done, lost their spirals to a gravity induced blob. So wait a minute; if this mass contains within it, over 1,100 galaxies it would have to be pretty far away right? Yea, you’re damn right it’s far away, how about 300 million light years away. When Hubble looks at this region it’s seeing the cluster as it looked 300 million years ago. If you were to travel around the Earth seven times per second, it would take you 300 million years to get there. As you can see, the speed of light is great for solar system travel, but it’s a crawl if we even wanted to traverse our own Milky Way.
Not only is this cluster massively large and incredibly far away, its moving fast; 15 million mph (24 million kph) in fact and that’s why I lovingly call it “Red Shift City.” That’s fast enough to where the gravity from the clusters themselves shouldn’t be able to hold the structure together. This was discovered by Fritz Zwicky back in 1933 and, although he didn’t know it at the time, he was stumbling into Dark Matter. As it turns out, dark matter accounts for nearly 90 percent of all the mass in this cluster, dwarfing the 1,100 galaxies and providing the mass needed to hold the cluster intact. Also, some galaxies are being called “dark galaxies” because they’re the size of the Milky Way and contain only one percent of the stars that the Milky Way does. That means that these particular galaxies mass is roughly 98 percent Dark Matter.
Now let’s go back to the image. At the center of this cluster lies two supermassive elliptical galaxies cataloged as NGC 4889 and NGC 4874. The biggest and brightest blob near the center of this image is NGC 4889, a 230,000 light year diameter elliptical galaxy and Hubble has detected a sleeping giant within it. At its core there’s a supermassive black hole with a mind jarring mass of 21 billion solar masses. That’s 21 billion times more massive than our Sun. According to the ESA Hubble press release (see below) its event horizon spans 130 billion km or 81 billion miles. In comparison, Sagittarius A (the Milky Way’s supermassive black hole) 26,000 light years away has an estimated mass of 4 million Suns.
NAME: New General Catalog 4889, NGC 4889.
WHAT IS IT?: Elliptical galaxy with supermassive black hole.
HOW BIG IS IT?: The black hole event horizon is 21 billion solar masses with a diameter of 130 billion km or about 81 billion miles.
HOW FAR AWAY IS IT?: 300 million years.
APPARENT MAGNITUDE: A very dim 13.
WHERE IS IT? (General): Member of the Coma Cluster of galaxies (Abell 1656).
WHERE IS IT? (Exact RA/DEC J2000): RA 12h 59m 49s / DEC +27° 58′ 50″.
ESA Hubble press release: https://www.spacetelescope.org/news/heic1602/