Admin Table of Contents
What are the differences between galaxies?
Galaxies are classified by their shape. Each type has different characteristics and a different history of evolution. Some, like the Milky Way, have arms spiraling outward around their center. Elliptical galaxies have less dust than their spiral counterparts, and so the star-making process has all but ended.
How do elliptical galaxies compared to spiral galaxies?
Spiral galaxies have a central bulge of stars surrounded by a disk that contains arms, which form a spiral structure. Elliptical galaxies don’t show any structure, but have a smooth ellipsoidal shape, appearing as a large spherical or elliptical ball of stars.
What are three main differences between spiral galaxies and elliptical galaxies?
Spiral galaxies have a flat disk like shape and a bulging center with spiral arms consisting the disk. Elliptical galaxies are ellipsoids with no clearly visible internal structure. Spiral galaxies have a very dense nucleus and a region of stars bulging outwards from the disks and, therefore, called the central bulge.
What are the four basic types of galaxies?
The four types of galaxies are spiral, barred spiral, elliptical and irregular. Each group spans large variations in size, number of stars, star density and general configuration.
What scientist discovered the three main types of galaxies?
Almost all current systems of galaxy classification are outgrowths of the initial scheme proposed by the American astronomer Edwin Hubble in 1926. In Hubble’s scheme, which is based on the optical appearance of galaxy images on photographic plates, galaxies are divided into three general classes: ellipticals, spirals, and irregulars.
What are the four names of the galaxies?
There are four types of galaxies: elliptical, spiral, barred spiral, and irregular. Most galaxies are between 1 to 100 parsecs away and 3 to 300 light-years in diameter. Once estimated at 200 billion, the number of known galaxies is now believed to be 2 trillion.
What are the three shapes of galaxies?
Astronomers group galaxies by shape, and although there are many different types of galaxies, most fall into one of three categories: spiral, elliptical or irregular.