Stars were massive, glowing, spheres of plasma and gas that produced their own light and energy. Stars that were the central body of a planetary system were referred to as suns.
The star Kessa
Stars were large celestial bodies that generated heat, light and radiation and consisted of a mass of burning plasma and gas. Resistance member Karé Kun once referred to them as "giant balls of exploding gas." Prime Minister Dreand Yens once remarked that stars only twinkled in the sky because they were burning to stay alive, which he believed was proof that nature's beauty came from function. During the High Republic Era, stars were assigned to a specific class by their chemical properties, such as R-class stars being unusually nitrogen-heavy.
A human's skin could darken from sun exposure; Sergeant Tonra usually had a pale complexion, but after spending two weeks in the sun, his skin reddened significantly. Human infants needed to be protected from the sun; when Sola Naberrie was preparing to spend the day outdoors with her newborn baby Ryoo, she needed to get Ryoo's sun protection first.
There were seven types of main sequence stars in the galaxy:
- "" stars were blue, and had a lifespan of less than one million years. Example: Garnib.
- "" stars were blue-white, and had a lifespan of ten million years. Example: Kessa.
- "" stars were white, and had a lifespan of four hundred million to two billion years. Example: Colu.
- "" stars were yellow-white, and had a lifespan of four billion years. Example: Ropagi.
- "" stars were yellow, and had a lifespan of ten billion years. Example: Corell.
- "" stars were orange, and had a lifespan of sixty billion years. Example: Yavin.
- "" stars were red and emitted little light or heat. They had a lifespan of over one hundred trillion years. They were also called . Example: Barab.
With O-class stars being the biggest in the sequence, the size decreased gradually to the smallest M-class stars.
The non-main sequence stars include:
Pre-main sequence (smaller than M-class stars):
- Brown dwarf. Example: Doornik-1142.
- Protostar. Example: Black Bantha Nebula.
Post main-sequence (bigger than O-class stars):
- Red giant. Example: Sokor.
- Blue giant. Example: Ku'Baku.
- Red supergiant. Example: Primus Goluud.
Compact stars:
- White dwarf. Example: Ardos.
- Black dwarf. Example: A star in the The Ring.
- Neutron star. Example: Oolex pulsar.
- Black hole. Example: Endor Gate.
Other exotic star types existed that did not fit precisely into this system of classification. These included Asar, considered a blue dwarf, and .
Stars formed in areas of space known as stellar nurseries, through a collision of energies in the form of pressure and heat, a process which shaped the space around it and could be seen from millions of kilometers away. The ignition of a planet's core by an outside force could also result in the formation of a star. Chirrut Îmwe once remarked that the "strongest stars" had kyber at their center. After their birth, stars went through various stages during their life, such as a yellow dwarf expanding to become a red giant. Plants drew sustenance from sunlight.
A field of stars
Most stars were orbited by a set of planets and other bodies. In that case, they were referred to as suns. A sun, together with all the bodies bound to it, formed a planetary system. In some cases, a planetary system could contain several suns, as was the case around the planets of Tatooine and Mon Cala. Life could not exist without stars.
A planet revolving around a star normally received light and warmth from it, although there were exceptions. Umbara was known as the "Shadow World" because the rays of its sun never completely reached the planet's surface, keeping it in perpetual darkness. In the night sky, remote stars looked like mere points of light. By convention, those points of light were grouped into constellations. Without a star, most worlds would become lifeless and frozen. The size and distance of a sun would affect many of the features of a planet orbiting it.
On the planet Coruscant, stars were hard to see, due to all the city lights of the sprawling ecumenopolis. However, according to young Obi-Wan Kenobi, one could see them if they knew how to look. Stars could be used for navigation: When young Kenobi returned to the Jedi Temple after trying to help fellow Jedi Initiate Gehren Rand, who had run away, he used the stars to find his way home.
- Star Wars: Jedi Temple Challenge — "Episode 2"
- Star Wars: Jedi Temple Challenge — "Episode 3"
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