Vulcan (also known as Vulcan/Vulcanis A II, Nevasa II or 40 Eridani A II) is a planet, the second planet in the 40 Eridani star system, in orbit of the star 40 Eridani A. A class M desert planet, Vulcan is inhabited by the Vulcan civilization, who refer to their world as T'Khasi, Minshara or Ti-Valka'ain. As the Vulcan homeworld Vulcan is the capital planet of the Confederacy of Vulcan, and a founding world in both the Coalition of Planets and United Federation of Planets. (Last Unicorn RPG modules: The Way of Kolinahr, Planets of the UFP; Decipher RPG module: Aliens; ST references: Star Charts, The Worlds of the Federation; ENT novel: Kobayashi Maru)
This world is known as vulqan to speakers of Klingonese. (ST reference: The Klingon Dictionary)
Vulcan orbits 40 Eridani A, known as Nevasa to the Vulcans, the primary orange K class star in the trinary Vulcan system. The other two stars in the system, 40 Eridani B and C, blue and red dwarfs respectively, co-orbited the A star at some distance and were not immediately visible in the Vulcan sky. (ST references: The Worlds of the Federation, Star Charts; TOS - Vulcan's Soul novel: Exodus; Decipher RPG module: Aliens)
- The ST reference: Star Trek Maps identified the system's first world as the planet Vulcan itself, omitting all references to additional planets beside Vulcan's sister world. While most other licensed sources mention Vulcan as the second planet, some (such as FASA RPG module: The Federation) refer to it as the third world, although this is an understandable notation as Vulcan is locked in orbit with third planet T'Khut). The ST reference: Spaceflight Chronology mentions Vulcan as the third planet, but contradicts canon in stating that Vulcan is located at Epsilon Eridani. Likewise, the Star Trek Online website's defunct Points of Interest section stated that Vulcan is located in the Sirius system, though STO itself uses the 40 Eridani location. All other sources since ST reference: Star Fleet Technical Manual agree that 40 Eri is the system.
Vulcan's orbital period (year) is 203 days long.  According to another source, Vulcan has an orbital radius of 0.56 AU, giving it a period of 177.6 standard days. However, the Vulcan calendar has set the Vulcan year to be about 1.5 times that, or 266.4 standard days. (DTI novel: Watching the Clock)
Vulcan has no moon, but did have a number of nearby planets, most notably T'Khut, with which it shares an orbit around a common center of gravity; the two worlds were a mere 149,895.3579 kilometers apart, and T'Khut would fill the sky of the single hemisphere of Vulcan it was visible from due to the planets being tidally locked. (TOS episode: "The Man Trap"; ST reference: The Worlds of the Federation; TOS novel: Sarek)
T'Khut itself does have a moon, called T'Rukhemai, home of the Vulcanis Lunar Colony. (TOS novel: Sarek; VOY episode: "Unimatrix Zero"; VOY novel: Pathways)
Also passing near enough in its orbit that Vulcan can be clearly seen in the sky was the icy planet Delta Vega. (TOS movie: Star Trek; TOS comic: "Nero, Number Four")
Vulcan was noted on star charts of the galaxy's explored regions in the 23rd and 24th centuries, in an area of the projection also containing Sirius, Altair VI and Aldeberan. (TOS movie: The Undiscovered Country, TNG episodes: "Conspiracy", "The Measure of a Man", "The Emissary", "The Mind's Eye", "The Game", DS9 episodes: "In the Hands of the Prophets", "Cardassians")
Vulcan is a harsh, desert planet with barely a quarter of its surface area containing water. It possesses a thin atmosphere and high gravity (1.4 G). (Decipher RPG module: Aliens)
Furthermore, solar radiation is noted to be much higher when compared to other M-class planets such as Earth. (TOS novel: Captain's Glory)
Vulcan has three primary continents called Na'nam, Han-shir and Xir'tan. The first are enormous land masses that were divided into various provinces whilst the third was an island somewhat larger than the Earth continent of Australia. (Last Unicorn RPG module: The Way of Kolinahr: The Vulcans)
Due to the strong tidal forces brought about by the planet's interaction with T'Khut Vulcan was highly volcanically active. This generates a number of impressive lava spectacles, such as the Fire Plains. (ST - New Worlds, New Civilizations short story: "Tempered by the Forge"; ENT episode: "Home")
Around four to five billion years ago, Vulcan was a highly geologically active environment. (TOS novel: Firestorm)
Furthermore, there are frequent energy discharges in the air that shimmered in the red sky in a region near the Gateway where there was an area that had a distorted magnetic field as a result of Vulcan's ancient atomic wars.
This serves as a form of third magnetic pole that disrupted most electrical as well as transtator currents in the region that are instead absorbed energy leak out into the wind. This is responsible for creating the spectacular lightning displays that are often seen in the clouds of sand. (TOS novel: Captain's Glory)
Vulcan's geology and desert environment produce starkly up-thrust craggy and inhospitable mountains, with jagged and steep formations cut out by wind swept sand. (Decipher RPG modules: Aliens, Worlds)
Vulcan maintains the oxygen in its atmosphere by deriving phytoplankton from its oceans, which existed as microscopic organisms that make up 90% of all planetary oxygenation processes, including those of Earth. Despite being a desert planet and not having a suitable source of oxygen in viable plant-life throughout most of their year, there is a sufficient amount of oxygenation occurring within the environment from the microbic water.
Though a dry desert occupied 96% of the planet's surface by the 23rd century, fossil records indicated that early Vulcan possessed 90% water along with a few islands with nothing but a hot sea present on the planet. Thousands of years later, when the proto-Vulcans developed and began to form tribes, 40 Eridani A erupt a massive solar flare that scorched the planet's surface; resulting in many native creatures dying, those which survived taking shelter in caves or other safe places on the opposite end of the planet. (TOS novel: Spock's World)
Early in the Dominion War, Benjamin Sisko expressed his concerns to Admiral Zach Warner that the Dominion would eventually be able to invade Vulcan if Starfleet kept up its defense posture. The routes between Vulcan and Earth and Alpha Centauri were critical to the Federation. (DS9 novelizations: Call to Arms..., ...Sacrifice of Angels)
The concerns for Vulcan lasted throughout the year, with fighting near the Vulcan border. Later, the fall of Betazed made the possibility of an invasion of Vulcan very likely. (DS9 episodes: "Favor the Bold", "In the Pale Moonlight", "The Reckoning")
During the Borg Invasion of 2381, several Borg cubes moved to attack Vulcan. They managed to begin an orbital bombardment which inflicted severe damage to notable locations on the planet, including the Vulcan's Forge. However, the planet was saved from destruction when former Earth Captain Erika Hernandez managed to influence the collective to attack itself, severely damaging the cubes attacking Vulcan, which were later destroyed by a Starfleet task force including the USS Atlas and USS Prometheus. (ST - Destiny novel: Lost Souls)
In 2468 of a timeline where the Federation chose not to intervene in the fight between the Borg and Cybermen, the Cybermen invaded Vulcan. Using his TARDIS, The Doctor and Jean-Luc Picard from 2368 witnessed these events. (TNG comic: "Assimilation², Issue 5")
In the alternate timeline created by Nero's temporal incursion, Vulcan was destroyed in the year 2258. The planet was obliterated by an artificial singularity created when Nero launched a red matter device into the planet's core. Of a population of 6 billion, approximately ten thousand escaped the devastation, and though their cultural legacy would survive, the Vulcan people became an endangered species. (TOS movie & novelization: Star Trek)
- The Decipher RPG module: Worlds and an early book in the Last Unicorn RPG exhibit some consistency in their depiction of Vulcan geography, while the early The Worlds of the Federation shows a different Vulcan surface, which has much less ocean and more minor lakes.
Continents and provinces
- Kel Province
- Gol • Khomi • Kir • Raal • Shi'al • Tat'Sahr
Bodies of water
- Great T'Kala Sea • Lake Yuron • Strait of Ha-zen • Thanar Sea • Voroth Sea
Mountains and volcanos
- Llangon Mountains • Mount P-Ta • Mount Tarhana • Mountains of Gol (Mount Seleya) • T'Raan • T'Regar • T'Riah
- Caves of Kolinar • Cheleb-khor • Fire Plains • Go'an • Ishaya plain • Nal'shin • Na'Ree • Osana caverns • Raal • Shival Flats • T'Ralor • Vulcan's Forge Gateway • Plain of Blood • Womb of Fire) • Vuldi Gorge
Typically, there are no lost civilizations on the planet as new cities were always integrated into the older ones which meant that ruins remained. In addition, the planet's manufacturing and heavy industry has, for centuries, been conducted in the asteroid belt within the system. The only industry that was allowed on the surface were those that neither despoiled the environment nor disturbed its tranquility such as music crafting. (TOS novel: Dwellers in the Crucible)
The Vulcan population was approximately 4.9 billion in the year 2378. (ST reference: Star Charts)
- AraKahr • Da'kum'ulcha • Da'Leb • Fort Aba'kur • Jaleyi • Khir Ahl • Kir • K'Lan-ne • Kwil'Inor • Naweeth City • Rh'Iahr • SanaiKahr • ShanaiKahr • ShiGral • Shi'Kahr • T'lingShar • T'Paal • Ta'Vistar • Vulcana Regar • Vulcinis
- Ancients of Days • Diplomatic Institute • Hall of Ancient Thought • Hall of Voices • Temple of T'Panit • Temple of Amonak • Temple of Logic • T'Karath Sanctuary • Sarek School of Diplomacy and Ambassadorial Studies • ShiKahr Academy • Vulcan Science Academy • Vulcan Space Central • Vulcan Space Institute
The heat of Vulcan's summer often kills off most vegetation, with plant life only flourishing once the rains come. In times of drought, out in the desert carnivorous plants are able to survive by catching any animal weakened by thirst.
- Adun cactus • Ches'lintak • Cholla • Cir-cen • D'mallu • Favinit • G'teth • Gal-en-du'un • Gesper • Induku tree • Isuke bush • Kal'ta • Karanji • Kylin'the • Pel-tar'uk • S'gagerat • Sir-soss'im • Tir-nuk • Vulcan palm tree • Death Star • Wahmlat
- Aylak • Ch'kariya • Firebird • K'karee • Krovill • Lanka-gar • Le-matya • Mah-tor-pahlah • Myrmidex • Sa-te kru • Sandworm • Sand viper • Sehlat • Shatarr • Shavokh • Sundweller • Tcha'besheh • Valit • Vai-sehlat
In an alternate timeline in which Khan Noonien Singh won the Eugenics Wars and Humanity underwent genetic engineering en masse, the Khanate of Earth conquered Vulcan during the 21st century. The Vulcan government's unconditional surrender was presented to Khan in the rubble of the temple atop of Mount Seleya. The Vulcans remained helots of Humans well into the 24th century. (DS9 - Myriad Universes novel: Seeds of Dissent)