Search results
Results from the WOW.Com Content Network
The corotation circle is the circle around the galactic center of a spiral galaxy, where the stars move at the same speed as the spiral arms. The radius of this circle is called the corotation radius. Inside the circle the stars move faster and outside they move slower than the spiral arms. The Sun is located near the corotation circle of the ...
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae [1] and, as such, form part of the Hubble sequence. Most spiral galaxies consist of a flat, rotating disk containing stars , gas and dust , and a central concentration of stars known as the bulge .
On the right of the Hubble sequence diagram are two parallel branches encompassing the spiral galaxies. A spiral galaxy consists of a flattened disk, with stars forming a (usually two-armed) spiral structure, and a central concentration of stars known as the bulge. Roughly half of all spirals are also observed to have a bar-like structure, with ...
For disk galaxies, virtually all star formation occurs in the disk. In that case, the elongated rings are likewise confined to the disk, and collectively they evolve to appear as (possibly disconnected) segments of spiral arms: See (e.g) NGC 4414, as well as figures in. [2] In 1995, the spiral galaxy NGC 4414 was imaged by the Hubble Space ...
A galaxy typically comprises two or more spiral arms. [5] The collective configuration of these arms within a galaxy is referred to as a spiral pattern or spiral structure. [6] Around two thirds of all massive galaxies are spiral galaxies. [7]
When a galaxy forms, it has a disk shape and is called a spiral galaxy due to spiral-like "arm" structures located on the disk. There are different theories on how these disk-like distributions of stars develop from a cloud of matter: however, at present, none of them exactly predicts the results of observation.
The detection of a "treasure trove" of stars was only possible because the light from the 44 new stars was magnified by a large cluster of galaxies, called Abell 370, in front of it, according to ...
Spiral galaxies like the Milky Way contain stars, stellar remnants, and a diffuse interstellar medium (ISM) of gas and dust. The interstellar medium consists of 10 4 to 10 6 particles per cm 3, and is typically composed of roughly 70% hydrogen, 28% helium, and 1.5% heavier elements by mass.