Spiral galaxies are twisted collections of stars and gas that often have beautiful shapes and are made up of hot young stars . ... Most spiral galaxies contain a central bulge surrounded by a flat, rotating disk of stars.
What is a spiral galaxy simple definition?
Spiral galaxies are twisted collections of stars and gas that often have beautiful shapes and are made up of hot young stars . ... Most spiral galaxies contain a central bulge surrounded by a flat, rotating disk of stars.
What makes a galaxy a spiral galaxy?
More than two-thirds of all observed galaxies are spiral galaxies. A spiral galaxy has a flat, spinning disk with a central bulge surrounded by spiral arms . That spinning motion, at speeds of hundreds of kilometers a second, may cause matter in the disk to take on a distinctive spiral shape, like a cosmic pinwheel.
What is special about a spiral galaxy?
Spiral galaxies have a lot of gas, dust and newly forming stars . Since they have a lot of hot, young stars, they are often among the brightest galaxies in the universe. About 20% of all galaxies are spirals. We live in a spiral galaxy called the Milky Way.
What is a spiral galaxy kid definition?
Lesson Summary. A spiral galaxy is a galaxy that is shaped like a spiral, with a bulge in the center . Our Milky Way galaxy is a barred spiral galaxy, which means it has a bright line going through its center. Most spiral galaxies are barred galaxies, and most spiral galaxies have more than two arms.
How do we know we are in a spiral galaxy?
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. We can also detect the bulge at the center. Since we see spiral galaxies which are disks with central bulges, this is a bit of a tipoff.
What’s another word for spiral galaxy?
- barred spiral galaxy.
- spiral.
- spiral nebula.
What kind of stars are in a spiral galaxy?
Spiral Galaxies
It is dominated by young, blue Population I stars . The central bulge is devoid of gas and dust. As you might expect, the bulge is composed primarily of Population II stars. Type c spiral galaxies have the most gas and dust.
How many stars are in a spiral galaxy?
Estimate of stars varies from 200 billion to 400 billion . Milky way is a barred spiral.
What is the average separation between spiral arms?
We show for a typical arm cross-cut, a separation of 400 pc between the mid-arm and the dust lane (at the inner edge of the arm, toward the Galactic center).
How does a spiral look like?
| Galaxy Type Description | Sa spiral galaxy, type a | Sb spiral galaxy, type b | Sc spiral galaxy, type c | SBa barred spiral galaxy, type a |
|---|
What is the basic shape of a spiral galaxy?
Galaxy classification
Perhaps the most familiar kind of galaxy are spiral galaxies. They have a distinctive shape with spiral arms in a relatively flat disk and a central “bulge” . The bulge has a large concentration of stars. The arms and bulge are surrounded by a faint halo of stars.
What is the spiral shape?
spiral Add to list Share. A spiral is a coil or curl, like the shape of a piece of hair wound around your finger, a Slinky toy, or a corkscrew . A curve forming a series of circles that become gradually larger or smaller is one kind of spiral.
What are two types of spiral galaxies?
Spiral galaxies appear as flat, blue-white disks of stars, gas and dust with yellowish bulges in their centers. These galaxies are divided into two groups: normal spirals and barred spirals .
How big is a spiral galaxy?
Spiral galaxies come in a wide range of sizes, from 5 to 100 kiloparsecs across , have masses between 10 9 and 10 12 solar masses, and luminosities ranging from 10 8 to 10 11 time that of the Sun. The majority of spiral galaxies rotate in the sense that the arms trail the direction of the spin.
How do spiral galaxies keep their shape?
How can spiral galaxies keep their shape? (Advanced) The Milky Way and many galaxies are spirals. To keep the spiral, the outer stars must move faster than the inner stars . From Issac Newton on, we have known that the father a star is from the center, the slower it must travel.
