Astronomy Magazine

Elliptical Galaxies

Posted on the 02 May 2011 by Gabe12logan
Elliptical galaxies don't have spiral arms that look's like a monotonous elliptical clusters. They have very little inter-stellar gas, which is why there is no possibility for the creation of young stars. Because of that elliptical galaxies inhabit the old stars with very little heavy elements. Majority of stars do not orbit around the center, but moving in all directions. They dramatically varies in size - the largest and the smallest galaxies belong to this group. Giant galaxies are rare (NGC 4874 is 20 times greater than the average galaxy), but there are many dwarfs that contain so few stars that are transparent(about a million of their star is not enough to create an opaque disk).
In elliptical galaxies account for about 13%. They are denoted by the letter E, and numbered with axis ratio of spheroids. They are homogeneous and mostly without interstellar matter. Stars move in the complex 3-dimensional trajectories with different represented speeds.
Elliptical Galaxies
Elliptical galaxies are classified according to how flattened they look. E0 galaxy is very round, and E7 galaxy is very flattened. The number following the letter "E" defines galactic "ellipticity" - the ratio of large and small axis of the galaxy. Galaxies with large ellipticity have higher numbers.
Elliptical galaxies are built mainly of red and yellow stars, giants and dwarfs, but lacks the blue and white supergiants. Gas is almost absent in elliptical galaxies since stars sucked it. The stars are mostly very old. Elliptical galaxy glow slightly decreases from center to periphery. These galaxies, if they rotate at all, do so very slowly.
Elliptical galaxies are unlike spiral a lot monotonous, and, of course, the elliptical shape. They do not contain much interstellar gas, which means it does not create conditions for the birth of young stars. They inhabit an old star that moves freely. What for them is very characteristic is that they greatly vary in size.

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