Generally the boundary between "cluster" and "galaxy" is considered to be somewhere in the vicinity of a million stars.
stars solar system galaxies universe
No stars are actually a galaxy. All stars are stars and all galaxies are galaxies. Stars are found in galaxies. Some galaxies look like tiny dots in our night sky, so might look like a star, but they are not stars; they are galaxies.
All stars and galaxies are in the universe.
The number of the galaxies has never, nor likely to be, accurately counted. Certainly there are many billions. As there are many 100s of millions of stars in an average galaxy then the number of stars is uncertain, but very large.
That is related to their past history. Many galaxies have undergone collisions with other galaxies; this takes out most of the interstellar gas, and the galaxies can no longer form new stars. If I remember correctly, such galaxies will change into elliptical galaxies.That is related to their past history. Many galaxies have undergone collisions with other galaxies; this takes out most of the interstellar gas, and the galaxies can no longer form new stars. If I remember correctly, such galaxies will change into elliptical galaxies.That is related to their past history. Many galaxies have undergone collisions with other galaxies; this takes out most of the interstellar gas, and the galaxies can no longer form new stars. If I remember correctly, such galaxies will change into elliptical galaxies.That is related to their past history. Many galaxies have undergone collisions with other galaxies; this takes out most of the interstellar gas, and the galaxies can no longer form new stars. If I remember correctly, such galaxies will change into elliptical galaxies.
no, the milky way is a typical barred spiral with about 200 billion stars some dwarf galaxies my only have a few million stars in fact, there are 2 dwarf galaxies orbiting the milky way that are much smaller
Galaxies are vast collections of stars. So I guess you could say that a big group of stars forms a galaxy. Our galaxy has many big clusters of stars within it, so not all star clusters are galaxies. If you have a cluster of several million or billion (or trillion) stars surrounded by a lot of empty space, that is probably a galaxy.
Billions at least, in the large galaxies. Obviously it depends on the size of the galaxy. It is estimated that in our Galaxy there are at least 100 billion and perhaps as many as 400 billion stars. Many galaxies are same sort of size as ours and some are much bigger. However, there are a lot of small "dwarf galaxies" The smaller dwarf galaxies have millions rather than billions of stars.
Anywhere between 100 and 1,000 billion stars
The largest galxies have stars numbering in the tens of trillions.
Yes, there are stars between galaxies. When there are collisions or interactions between galaxies, stars can be ripped out of the galaxies. These stars will then wander into space between galaxies. Such stars have been observed with the Hubble Space Telescope. Taken from http://curious.astro.cornell.edu/question.php?number=384
Smaller galaxies do. Larger galaxies contain billions or even trillions of stars.