Stars dot the... Void? Map? Expanse? At any rate, there's a lot of them in Orion's Spur, our little neck of the woods:
List[edit | edit source]
Red Giant[edit | edit source]
A red giant is a luminous giant star in the later stages of its lifespan. The outer layer inflates creating a large radius with surface temperatures around 5,000 K. It appears as spectral types K and M. The most common red giants are stars on the red-giant branch which are fusing hydrogen into helium in a shell surrounding a dead helium core.
Blue star[edit | edit source]
O-type stars are a brilliant blue-white. Stars of this type are defined by their Helium II absorption lines and strong lines of ionised elements.
Blue Stars are very rare; only 0.00003% of the main sequence are O-type stars.
Brown dwarf[edit | edit source]
These substellar objects are something between a heavy gas giant and the smallest of stars. Their mass is roughly between 80 times that of our own Jupiter. Anything smaller is classified as a sub-brown dwarf and anything larger is a small red dwarf.
Despite their rather dull name, brown dwarfs are typically magenta in color to the naked human eye, or sometimes a shade redder. They do not give off much visible light.
Red dwarf[edit | edit source]
A red dwarf is a small main sequence star of the M spectral type. They are fairly cool, with a temperature of less than 4,000 K. Sometimes main sequence K-type stars are also included in this category.
Red dwarfs are in fact the most common type of star in the Orion Spur. However, because of their relatively low luminosity they are difficult to see in the night sky. Proxima Centauri, the nearest star to our own, is in fact a red dwarf star.
White dwarf[edit | edit source]
These stellar core remnants are mostly just electron-degenerate matter. White dwarves are incredibly dense with a mass near that of our own Sun contained in a volume closer to that of Earth.
A white dwarf's luminosity is generated from the emission of stored thermal energy. There is no fusion, as white dwarves are effectively dead stars. The nearest white dwarf to us is Sirius B.
Yellow star[edit | edit source]
Often referred to as a G-type main-sequence star, a yellow star, in particular a yellow dwarf is in fact what our own sun is. Like other main-sequence stars these convert hydrogen into helium at their core. Besides our own sun, other well known yellow stars include Alpha Centauri A, Tau Ceti, and 51 Pegasi.