Table of Contents
What is a spiral galaxy best described as?
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.
Is a spiral galaxy shaped like a pinwheel?
Spiral galaxies have curved “arms” that make them look like a pinwheel. A galaxy is a huge collection of gas, dust, and billions of stars. Galaxies are held together by gravity.
Is a spiral galaxy spinning?
The Milky Way, an average spiral galaxy, spins at a speed of 130 miles per second (210 km/sec) in our Sun’s neighborhood. New research has found that the most massive spiral galaxies spin faster than expected.
What is the main difference between a spiral galaxy and a barred spiral galaxy?
Spiral galaxies They are divided into two parallel classes: normal spirals and barred spirals. The normal spirals have arms that emanate from the nucleus, while barred spirals have a bright linear feature called a bar that straddles the nucleus, with the arms unwinding from the ends of the bar.
How do you describe a galaxy?
A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. A galaxy is held together by gravity. Our galaxy, the Milky Way, also has a supermassive black hole in the middle. Some scientists think there could be as many as one hundred billion galaxies in the universe.
What is the closest galaxy to our galaxy?
Distance Information The closest known galaxy to us is the Canis Major Dwarf Galaxy, at 236,000,000,000,000,000 km (25,000 light years) from the Sun. The Sagittarius Dwarf Elliptical Galaxy is the next closest , at 662,000,000,000,000,000 km (70,000 light years) from the Sun.
How is a galaxy classified?
Galaxies are classified by shape. There are three general types: elliptical, spiral, and irregular. 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 do spiral galaxies spin?
About half of all spiral galaxies appear to be rotating clockwise and the other half counterclockwise. In most cases, spiral galaxies spin with their arms trailing the direction of rotation.
What is the difference between an elliptical and spiral galaxy?
They are considered to be younger than elliptical galaxies, which contain less dust and form fewer stars. Spiral galaxies come in a wide variety of shapes. Roughly 60 percent of spiral galaxies contain multiple arms, while another 10 percent have only two.
What are some examples of spiral galaxies?
The Milky Way – the galaxy that includes Earth and our solar system – is an example of a spiral galaxy. Spiral galaxies make up roughly 72 percent of the galaxies that scientists have observed, according to a 2010 Hubble Space Telescope survey.
What is the center of a spiral galaxy made of?
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. Approximately two-thirds of spiral galaxies also contain a bar structure through their center, as does the Milky Way.
Is the Milky Way a barred or unbarred spiral?
Approximately two-thirds of spiral galaxies contain a barred structure through their center, making unbarred spiral galaxies a minority. The Milky Way is one of these, though its bar is a challenge to see and was not suspected until the 1990s. Its barred structure was confirmed in 2005.