What types of stars are found in spiral galaxies?
What types of stars are found in spiral galaxies?
The bulge of a spiral galaxy is composed primarily of old, red stars.
Do spiral galaxies have O and B stars?
Spiral arms can be located with 21-cm line radiation, HII regions, O and B stars. In the Milky Way, visible light tracers like HII regions or O and B stars can only locate nearby spiral arms but dust prevents using these tracers on a wide scale in the Galaxy.
How many stars do spiral galaxies have?
Estimate of stars varies from 200 billion to 400 billion. Milky way is a barred spiral.
How are stars arranged in spiral galaxies?
The bulk of the stars in a spiral galaxy are located either close to a single plane (the galactic plane) in more or less conventional circular orbits around the center of the galaxy (the Galactic Center), or in a spheroidal galactic bulge around the galactic core.
What types of stars are in irregular galaxies?
Typically, irregular galaxies have lower masses and luminosities than spiral galaxies. Irregular galaxies often appear disorganized, and many are undergoing relatively intense star formation activity. They contain both young population I stars and old population II stars.
What are spiral galaxies characterized by?
Spiral galaxies Spirals are characterized by circular symmetry, a bright nucleus surrounded by a thin outer disk, and a superimposed spiral structure. They are divided into two parallel classes: normal spirals and barred spirals.
Why are O and B stars found in spiral arms?
The stars and gas and dust clouds in the disk congregate in a spiral pattern. The O and B-type stars live for only a few million years, not long enough to move outside of a spiral arm. That is why they are found exclusively in the spiral arms.
How do you classify spiral galaxies?
Spiral galaxies are classified as Sa/SBa, Sb/SBb or Sc/SBc (classic/barred) according to the tightness of their spiral, the clumpiness of their spiral arms, and the size of their central bulge. These differences can be traced back to the relative amounts of gas and dust contained within the galaxies.
How many stars are in a galaxy?
An incredible number. Red, white and blue stars give off different amounts of light. By measuring that starlight – specifically, its color and brightness – astronomers can estimate how many stars our galaxy holds. With that method, they discovered the Milky Way has about 100 billion stars – 100,000,000,000.
What are the 4 different types of galaxies?
Galaxies 101 Scientists have been able to segment galaxies into 4 main types: spiral, elliptical, peculiar, and irregular.
What are the classification groups for galaxies?
Edwin Hubble invented a classification of galaxies and grouped them into four classes: spirals, barred spirals, ellipticals and irregulars.
