That is a star cluster.
globular
globular cluster
All planets and stars are approximately spherical in shape, a shape formed under their own gravity. Most are `oblate` spheroids though, squashed spheres, since their rotation can cause them to `bulge` out at the equator if it is sufficient enough.
Gravitational Force
Actually the terms "Globular" and "Open" are not related to the number but the age of the stars. Globlular clusters are many old stars packed in spherical form (they look like hazy mothballs to the naked eye) and "open clusters" are many young stars formed close to each other. The constellation Pleiades is an example of open cluster.
The bulge is a tightly packed group of stars within a larger formation. In the case of the Milky Way Galaxy our "bulge" is the galactic centre.
globular
globular cluster
globular cluster
Stars are spherical in shape. They are balls of hot gas. If a star is spinning fast enough, it will bulge a bit around the middle, but it will still be pretty close to a sphere.
Nothing to be trifled with. : P In astronomy it is the almost spherical layer of stars surrounding the center hub of our galaxy. A layer in the onion, so to speak. It is a widening near the core (the centre) of a galaxy and consists of mainly very old stars. Very rare for new stars to form because of the lack of dust and gases between the stars. Surrounding this central bulge is what's called the galactic halo, which is made up of individual stars.
Spherical
All stars are approximately spherical.
All planets and stars are approximately spherical in shape, a shape formed under their own gravity. Most are `oblate` spheroids though, squashed spheres, since their rotation can cause them to `bulge` out at the equator if it is sufficient enough.
Spherical
It is called simply a "globular cluster". Another possibility: The closely allied stars at the center of a galaxy tend to be older, redder stars than those in the outlying arms of the galaxy.
Stars form in all parts of our galaxy - not just the "arms". Stars do indeed form in the central bulge. The vast majority of hot, young, blue stars are formed in the arms, but stars also form in the central bulge as well.