As I write this blog post, I am absolutely starving. I tend to eat my dinners early in the evening and I’m a broke college student on a budget. As a result, around 9 o’clock I am in desperate need of a snack. I’m hungry enough to eat a horse. I’d venture a guess that I’m hungrier than absolutely anything in the galaxy. However, unless I’m hungry enough to eat 12 Earths, I’m not even close.
Meet Sagittarius A*, the voracious black hole that lies at the center of our Milky Way galaxy. Estimates say that this black hole has the equivalent mass of at least 4 million suns. This is an easy statistic to listen to before immediately shrugging it off, but when this is truly considered it is jaw dropping. To put this in perspective, I weigh about 160 pounds (impressive, I know) and my mass is 72.5 kilograms. We will call 72.5 kilograms, “1 Student Mass.” Therefore, using the commonly accepted values for the mass of the Earth and Sun, 8.2 x 10^22 Student Masses = 1 Earth Mass, then 333,000 Earth Masses = 1 Sun Mass and finally, 4 million Sun Masses = 1 Sagittarius A* Mass. Multiply it all together, and you find out that the mass of Sagittarius A* is equal to the mass of 10^35 students my size.
Numbers this massive are nearly impossible to comprehend. I’ll try to show how enormous these numbers are. If these 10^35 students that were all 6 feet tall were lined up end to end, they wouldn’t even come close to fitting within the bounds of the universe as we know it. What’s even more mind boggling is that all of this mass is compressed into an infinitesimally small point, known as the singularity, which has no height, depth or width. Numbers like these are shocking yet commonplace amongst black hole discussion.
I mentioned being “hungry enough to eat 12 Earths” earlier because Sagittarius A* is in the middle of eating one of the bigger meals of its life. Astronomers are currently enjoying the rare spectacle of watching a 12 earth mass gas cloud known as G2 swing around the center of the black hole and get sucked into its clutches. This is so exciting because astronomers usually only see interesting things happen after the fact.
The gas will be continually gobbled up by the black hole over the next few months and astronomers will be observing to see if any “fireworks” happen. Fireworks would involve the area surrounding the black hole getting considerably brighter. No matter what happens, the event will be a time for black hole theorists to see what is actually going on.
It’s a very exciting time to learn about Sagittarius A* and all of the secrets it hides. The biggest secret? How does it eat so much and stay so thin?!