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What shape is a spiral galaxy?

What shape is a spiral galaxy?

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.

Are spiral galaxies shaped like discs?

To begin, disk galaxies, also known as spiral galaxies, are shaped like a fried egg- with a spherical center surrounded by a disk of gas and stars. This causes their collective mass to increase, and their gravitational force to grow until the gas collapses into a swirling disk.

What two types of shapes does a spiral galaxy have?

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. In barred spirals, the bar of stars runs through the central bulge.

Why is the galaxy spiral shape?

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 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.

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

What is the major difference between an elliptical galaxy and a spiral galaxy?

Spiral galaxies have both young and old stars, whereas elliptical galaxies have only old stars. Among the large galaxies in the universe outside of clusters, most are spiral. Elliptical galaxies are bluer and contain more dust than spiral galaxies.

What causes the spiral to behave?

These galaxies are differentially rotating–that is, the time to complete a full rotation increases with distance from the center. Differential rotation causes any disturbance in the disk to wind up into a spiral form. That force helps maintain the spiral form against the tendency to wind up.

What does a spiral shape look like?

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 causes the shape of the spiral galaxy?

Astronomers believe that galaxies have spiral arms because galaxies rotate – or spin around a central axis – and because of something called “density waves .”

What is the largest spiral galaxy?

Papers by Eufrasio, et al., and citing these, NASA , repeatedly state that NGC 6872 is the largest known spiral galaxy, but various sources report that LSB galaxy Malin 1 is the largest spiral at 650,000 light-years (200,000 pc) across.

How many different shapes of galaxy are there?

Thanks to the work of famous astronomer Edwin Hubble we know that just about any galaxy in the universe will have one of 4 different shapes, spiral, elliptical, lenticular, and irregular. Spiral galaxies are one of the most familiar galaxy shapes.

How many stars does a spiral galaxy have?

There are spiral galaxies out there with more than a trillion stars, and giant elliptical galaxies with 100 trillion stars. And there are tiny dwarf galaxies with a fraction of our number of stars.