The term 'bulge' is used to describe the dense spheroidal swarm of stars often found in the centres of spiral and S0 galaxies. … Recent observations have revealed the presence of young, massive stars in the bulge, a sure indicator of recent star formation.
What is bulging in the center of galaxies?
What is the central bulge in a galaxy?
In Milky Way Galaxy: The central bulge. Surrounding the nucleus is an extended bulge of stars that is nearly spherical in shape and that consists primarily of Population II stars, though they are comparatively rich in heavy elements.
Why is there a bulge in the center of the Milky Way?
In the past, astronomers thought that the bulge was made up of old stars, researchers said in a statement, but a growing body of evidence has revealed young stars, as well. Combined with other observations, this suggests that the Milky Way may have suffered a collision with another galaxy in its past.
Does the galaxy bulge in the middle?
Our Milky Way galaxy is shaped like two fried eggs glued back-to-back. A central bulge of stars sits in the middle of a sprawling disk of stars. Though this is a common feature among myriad spiral galaxies, astronomers have spent decades puzzling out how and when the Milky Way's central bulge might have formed.
What is in the middle of a galaxy?
Almost every galaxy, including our Milky Way, has a supermassive black hole at its heart, with masses of millions to billions of times the mass of the Sun. Astronomers are still studying why the heart of galaxies often hosts a supermassive black hole.
What is a central bulge made of?
A galaxy's bulge is a central, football-shaped structure composed of stars, gas, and dust. The dark material surrounding the center of the galaxy is gas and dust that is being funneled into the central region by the bar.
How big is the central bulge?
One of the most important and massive parts of the galaxy is the galactic bulge. This huge central cloud of about 10 000 million stars spans thousands of light-years, but its structure and origin were not well understood.
Do all galaxies have a bulge?
One study has suggested that about 80% of galaxies in the field lack a classical bulge, indicating that they have never experienced a major merger. The bulgeless galaxy fraction of the Universe has remained roughly constant for at least the last 8 billion years.
Do irregular galaxies have a bulge?
Irregular galaxies have no identifiable shape or structure to them. They are often chaotic in appearance, without a bulge or any trace of spiral arms. The different shapes and orientation of galaxies are a result of their history, which may have included interactions with other galaxies.