Let me clarify one thing... Basically, ALL galaxies, or almost all of them, have a giant black hole at their center. (If any galaxy does NOT have such a supermasive black hole, then it is likely that it had one in the past, and that it was ejected out of the galaxy.)
quasar
A central dominant galaxy is typically the largest and most massive galaxy at the center of a galaxy cluster. It is surrounded by smaller satellite galaxies and can influence the dynamics and evolution of the entire cluster through its strong gravitational pull. These galaxies often exhibit unique properties compared to other galaxies in the cluster.
To understand the 'how' of the presence of a supermassive black hole believed to be in the center of the Milky Way, one would need to know of the mechanism of its origin, which is tied to the origin of the galaxy itself. If sufficient matter is present in a given location, gravitational forces cause the matter to 'clump' and if sufficiently strong, it will continue to accrete and gain in mass; above a certain mass, given favorable conditions, a black hole will form. This is believed to have happened during the formation of our galaxy. In the case of the black hole at the galactic center, calculations indicate it has managed to acquire over four million solar masses.
The first time an object was viewed as a black hole by most astronomers was in 1971. Prior to that, most astronomers were skeptical such an object even existed, let alone that one had been detected.
Yes. VY Canis Majoris is about 4 billion kilometers across. This is comparable to the diameter of the event horizon of a 1.3 billion solar mass black hole. Black holes much larger than this have been detected in the centers of distant galaxies.
It's not "galaxy stars", but galaxies, that have the black holes at their center.All, or most, galaxies have a giant black hole at their center.
quasar
In the center of every galaxy there is a giant black hole.
Yes, incuding a giant one at the center.
Yes, there is believed to be a super giant black hole at the center of every galaxy.
A giant elliptical galaxy at the center of a dense cluster
No, Betelgeuse is not a quasar. Betelgeuse is a red supergiant star located in the constellation of Orion, while a quasar is a highly energetic and distant active galactic nucleus powered by a supermassive black hole at the center of a galaxy.
B.) A giant elliptical galaxy
At the centre of our Galaxy, the Milky Way
The rotation of the Milky Way is the result of the gravitational pull of a giant (supermassive) black hole at its center. Use the links below for more information.
There are lots of giants in our galaxy. Betelgeuse is very big (about 20 of our Suns). The massive object / system (expected to be a supermassive black hole) at the center of the Milky Way has the mass about 2.6 million of our Suns.
Most galaxies have a gigantic black hole in their center. The black hole in the center of our galaxy is estimated to have 4 million times the mass of our Sun. Some larger galaxies have black holes with billions of times the mass of our Sun. It is not yet understood how such a large black hole could form.