Here's what we know about it:

* Massive: It has a mass about 4 million times that of our Sun.

* Invisible: Like all black holes, it cannot be seen directly as it doesn't emit light. However, we can detect its presence through the effects of its gravity.

* Active: Sgr A* is relatively quiet compared to some other supermassive black holes, but it does emit radio waves and X-rays.

* Surrounded by a disk: A disk of gas and dust swirls around Sgr A* before being pulled into the black hole.

Scientists are continuously studying Sgr A* to learn more about its behavior and the evolution of our galaxy.