Table of Contents
- 1 Do spiral arms contain star clusters?
- 2 Where is the bar in a barred spiral galaxy?
- 3 What are two main types of star cluster?
- 4 How do we know we live in a spiral galaxy?
- 5 How do you identify a barred spiral galaxy?
- 6 Why does the Milky Way have spiral arms?
- 7 Which is an example of a barred spiral galaxy?
- 8 How are irregular galaxies different from spiral galaxies?
Do spiral arms contain star clusters?
The spiral arms of galaxies are the the main production centres of young stars. The more gas and dust available, the greater the fraction of the galaxy that can be involved in star formation. Their arms contain more clusters of very luminous stars and more luminous nebulae (HII regions).
What do the spiral arms in spiral galaxies contain?
Most spiral galaxies contain a central bulge surrounded by a flat, rotating disk of stars. The bulge in the center is made up of older, dimmer stars, and is thought to contain a supermassive black hole. These spiral arms contain a wealth of gas and dust and younger stars that shine brightly before their quick demise.
Where is the bar in a barred spiral galaxy?
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure made of stars. Bars are found in around half of all spiral galaxies, and appear to influence the motions of stars, dust and gas. It is believed that bars act a bit like a funnel, by pulling matter into the bulge from the disk.
Do barred spiral galaxies have arms?
Few sights in the universe rival that of a dramatic barred spiral galaxy. These grand galaxies feature two massive spiral arms that sweep away from the ends of a huge bar, which forms the galaxy’s heart. As a result, such a galaxy looks like a sweeping letter S.
What are two main types of star cluster?
Star cluster, either of two general types of stellar assemblages held together by the mutual gravitational attraction of its members, which are physically related through common origin. The two types are open (formerly called galactic) clusters and globular clusters.
What stars are in spiral arms?
The arms of a spiral galaxy have lots of gas and dust, and they are often areas where new stars are constantly forming. The bulge of a spiral galaxy is composed primarily of old, red stars. Very little star formation goes on in the bulge.
How do we know we live in a spiral galaxy?
The clues we have to the shape of the Milky Way are: 1) When you look toward the Galactic Center with your eye, you see a long, thin strip. This suggests a disk seen edge-on, rather than a ellipsoid or another shape. 3) The gas fraction, color, and dust content of our Galaxy are like other spiral galaxies.
How does a spiral look like?
The most common type of galaxy is called a “spiral galaxy.” Not surprisingly, spiral galaxies look like spirals, with long arms winding toward a bright bulge at the center….Spiral Galaxies.
| Galaxy Type | Description |
|---|---|
| Sa | spiral galaxy, type a |
| Sb | spiral galaxy, type b |
| Sc | spiral galaxy, type c |
| SBa | barred spiral galaxy, type a |
How do you identify a barred spiral galaxy?
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about half of all spiral galaxies. Bars generally affect both the motions of stars and interstellar gas within spiral galaxies and can affect spiral arms as well.
What is an example of a barred spiral galaxy?
About half of spiral galaxies are barred; examples include M58 (SBc), M61 (SABbc), the Large Magellanic Cloud (LMC, Sm), … and our own Milky Way galaxy! The bars are mostly stars (usually), unlike spiral arms (which have lots of gas and dust besides stars).
Why does the Milky Way have spiral arms?
Astronomers believe that galaxies have spiral arms because galaxies rotate – or spin around a central axis – and because of something called “density waves.” A spiral galaxy’s rotation, or spin, bends the waves into spirals. Stars pass through the wave as they orbit the galaxy center.
What are star clusters good for?
Star clusters are particularly important because they allow astronomers to check models of stellar evolution and the ages of stars. They therefore share the same initial metallicity so any effect of this on stellar evolution is effectively the same for the members of the cluster.
Which is an example of a barred spiral galaxy?
Some spiral galaxies are what we call “barred spirals” because the central bulge looks elongated – like a bar. In barred spirals, the spiral arms of the galaxy appear to spring out of the ends of the bar. Examples of spiral galaxies imaged by the Hubble Space Telescope: spiral galaxy M74 (left) and barred spiral galaxy NGC 1672 ( right).
Is the Milky Way galaxy a spiral or spiral galaxy?
The bulge has a large concentration of stars. The arms and bulge are surrounded by a faint halo of stars. The bulge and halo consist mainly of older stars, where spiral arms have more gas, dust and younger stars. Our Milky Way Galaxy is a spiral galaxy.
How are irregular galaxies different from spiral galaxies?
Galaxy classification. They have a bulge and halo, like spiral galaxies, but don’t have the flat disk of stars. The stars in ellipticals tend to be older. 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.
What kind of stars are in an elliptical galaxy?
As their name suggests, elliptical galaxies are round or oval, with stars distributed fairly uniformly throughout. They have a bulge and halo, like spiral galaxies, but don’t have the flat disk of stars. The stars in ellipticals tend to be older.