Nearest Stars per Spectrum

Exoplanetary Scratchpad [SysBP Img]

Yellow-Orange Dwarves

Single Stars

• Solar System (G2, 0 ly) - Our home star system. Contains 4 terrestrial planets, 4 gas giant planets, several dwarf planets, an asteroid belt, and a kuiper belt, around a G-Class yellow dwarf star. Contains the only known habitable planet, Earth.
• Tau Ceti System (G8 Vp, 11.9 ly) - Tau Ceti is also known as HD 10700, HR 509, and Gl 71. The nearest single G-class yellow dwarf to the sun, somewhat smaller than the Sun. A popular science fiction subject and one of two targets of SETI-forerunner Project Ozma in the 1960s. Despite being somewhat older than the sun, it has an extensive asteroid and/or comet field 10-50 AU, with the bulk between 35 and 50 AU. It has about ten times as much material as the Sun. This would make life difficult. It is a metal deficient star, so it is thought less likely to host rocky planets. Traditional dopplar spectrometry has ruled out any large Jupiter sized planets at Jupiter like distances or closer in, which was thought to be good for any potentially habitable planets. Five candidate rocky super Earth planets were detected though using a new method of planetary detection. This method made predictions of the stellar "noise" activity that might obscure detection of a planet based on the long history of dopplar measurements done on this system. Deviations from this prediction pointed towards the existence of planets. Confirmation using more established methods is needed. These planets are labeled b through f as you go outward, span 0.1 AU to 1.35 AU, and get larger the further you go out (at least 2 ME to 6.6 ME). The outermost two are near the habitable zone and were originally hailed as possibly being the nearest and smallest known habitable planets. More recent modeling indicates they are not actually habitable though. Planet e is probably too close to the star and only in the HZ if generous assumptions are made. Planet f has probably only been in the habitable zone for about a billion years as a result of its star becoming hotter, which might make biosigns difficult to detect from Earth, considering it took 2 BY for biosigns to become detectable around the Earth. Since the star has a higher magnesium to silicon ratio than the Sun, these planets compositions could be quite different that the Solar System's. The lower mantles could be dominated with ferropericlase, which is not very viscious, which may make the rocks of the mantle flow easier than on Earth, affecting volcanism and tectonics. One of 5 PICTURE-C targets selected for sub-orbital coronograph observation.
• Alsafi System (G9, 18.8 ly) - Alsafi is also known as Sigma Draconis, HR 7462, Gl 764, and HD 185144. It's name is from derived from Arabic for a "cooking tripod" that nomads used. It has been reclassified in 2003 as a G9 Yellow Dwarf star (it was thought to be an orange dwarf). It has about 90% of the Sun's mass and 80% of its diameter. There appears to be a sunspot cycle, though its length is undetermined, and it was found to be the least variable of any of the stars observed by Hipparcos. It is thought to be 7 to 8 Billion Years old. It was a tier 1 target for Nasa's Terrestrial Planet Finder and a top target for ESA's Darwin project before both projects were put on indefinite hold. It was described as being the fourth easiest star to find terrestrial planets. No indication of any planets or dust disks have so far been detected. One of 5 PICTURE-C targets selected for sub-orbital coronograph observation.
• 82 G. Eridani System (G3, 19.8 ly) - 82 G. Eridani is also known as 82 Eri, HR 1008, Gl 139, and HD 20794. One of the nearest star systems with planets. It is one of the dimmer yellow dwarf stars. Has three radial velocity detected super Earth planets orbiting closer than the habitable zone. The outermost one d is the largest (5 times Earth's mass, twice its radius, rocky-water composition) is about the same distance as Mercury is from the Sun. The middle one c is 0.1 au closer and is the smallest (2.5 Earth's mass, 1.5 its radius) and is likely a rocky-iron in composition. The innermost one is at 0.1 AU and just slightly larger than c, but more massive and of a more rocky-water composition. A dust disk was also found about 20AU from the star. The 2007 book "Habitable Planets for Man", released prior to the discovery of the planetary system, placed this as the most habitable star system within reach of mankind.
• Delta Pavonis System (G5-8 V-VI, 19.9 ly) - Delta Pavonis is also known as Gl 780, HD 190248, and HR 7665. One of the nearest bright stars to the sun. Although somewhat smaller than the Sun, it is easily visible with the naked eye. It is about 6.8 Billion Years old. It has a New Suspected Variable designation NSV 12790 and appears unusually bright for a main sequence star, so may be starting to become a sub-giant. It was identified as the best SETI target of the nearest 100 G-type stars. It is the nearest solar-analog in a single system and is type G5-8 V-IV.
• Beta Hydri System (G2 IV, 24.4 ly) - Beta Hyi is also known as HR 98, Gl 19, and HD 2151. The nearest confirmed subgiant star to the Sun. It is a yellowish subgiant (G2 IV) evolved from a low F class main sequence star.
• Chara System (GO V, 27.3 ly) - Chara is also known as Beta Canum Venaticorum, Asterion, HR 4785, Gl 475, and HD 109358. Together with Cor Caroli, it forms the "Southern Dog" portion of the Hunting Dogs constellation. Its name Chara (Greek for "joy") used to apply to both stars, but is now only applied to this one. Nearby yellow dwarf star and Solar analog. It is slightly older than the Sun and rotates at a similar speed as the Sun. X-Rays have been detected, as would be expected. It was named in 2003 to be the most likely sun-like star old enough to produce a radio-wave producing civilization. An unconfirmed spectroscopic companion star with a 2,430 day period has been claimed.
• 61 Virginis System (G5-6 V, 27.8 ly) - A system containing a 5.1 ME Hot Super-Earth b (which is hot enough to have emissions on its night side) and one and possibly two other further out Neptunians (c and d [unconfirmed] and possibly a fourth), and a massive Kuiper Belt around a very Sun-like star only 28 light years away. All planets would fit inside Venus' orbit and have high eccentricities, especially the outermost one. This is the closest planetary system around a G-type star, which is one of the only very sun-like stars visible to the naked eye. It is the first non-borderline G-class main sequence star found to have a super-Earth. A lack of a Jovian planet and an unseen further out Neptunian may explain the large amount of cometary debris detected. Systems like this may avoid a heavy bombardment period, but instead undergo a steady rain of occasional cometary impacts for billions of year. Of the six sunlike stars within 10 parsecs, this star would be the one most likely to have an older version of Earth orbiting it. This postulated planet would have only microbes left as its star became hotter.

Multiple Stars

• Alpha Centauri System (G2 V, 4.4 ly) - Alpha Centauri is also known as Rigil Kentaurus. A is also known as HD 128620 and HR 5459, B is HD 128621 and HR 5460, and C is Proxima Centauri. It is the nearest star system to the Sun. Contains a yellow dwarf star a little bigger than the Sun and an orange star a little smaller orbiting each other orbiting each other about the distance Uranus is from the Sun (varies from Saturn like to Neptune like), as well as a distant Red Dwarf companion Proxima that may or may not be orbiting the other two.

    Stellar fingerprinting suggests a high probability that a planet orbits star A, due to dearth of Iron around star. Russian astronomers announced the detection of a second planet orbiting the binary pair at 80 AU with a 100 year period, which appears to be false. The stars in the system will become markedly closer together in 2016, making observations much more difficult and one follow up failed to find it. The system is the first target for the European Cheops exoplanet space telescope.

    A planet was thought to have been discovered around star B and detected by HARPS. It would have been an Earth-massed rocky-iron planet with no atmosphere at epistellar distances around the orange dwarf star B. This would have been the least massive planet found around a sunlike star. The planet was informally and controversially named by Uwingu during a fund raising naming contest Albertus Alauda, after a participant's grandfather. Earthlike planets are not detectable in the habitable zone with present radial velocity methods. Technique for detection of planet is a source of doubt for some and it has yet to be independently verified. A team thought they might have detected a transit of this planet, but further observations showed the timing wasn't consistent. It is possible that a second further out (20.4 day period) Earth-sized planet is altering the transit times of the first. A cheap crowdfunded satellite devoted to studying this star could confirm the planets. The star was observed to be a good candidate to host a "super Habitable" planet, which would have 25% more gravity than the Earth, shallow seas, flatter landscape, higher atmospheric pressure, and the 6 BYO star would be stable for life longer.

    Proxima, a small flare star, was discovered in 1915 by Robert Ines, who named it. Long suspected planet around Proxima found not to exist. The Pale Red Dot project is dedicated to finding a planet around Proxima using dopplar spectrometry. As Proxima passes in front of two stars (once in 2014, again in 2016), any planets within 5 AU should be detectable via microlensing using the HST. It is known that no planets of Neptune sized mass exist within 1 AU and no Jovians with periods up to 1000 days, or transiting planets exist. An Earth-like planet in the habitable zone was discovered around Proxima Centauri. In 2017, a large stellar flare erupted and bombarded the planet, making it likely that the atmosphere has been completely stripped away by events such as this and not a good candidate for life. It was thought that a lot of dust existed in the system, making it feasable that the star had a rich complement of planets, but this seems to not be the case.

• Archird System (G3, 19.4 ly) - Archird is also known as Eta Cassiopeiae and Gliese 34. Nearby yellow dwarf star (A) orbited by an orange dwarf star (B). It is the brightest star near the lines formed by the "W" of the constellation. Star A is also known as HR 219, LHS 123, and HD 4614, while Star B is also known as LHS 122. Star A is about the same size, mass, and age as the Sun, but only about 65% as metal rich. It represents what the Sun might look like from Archird. Its habitable zone is centered on 1.35 AU. At one time, Star A was thought to have a spectroscopic binary companion with a nine day orbit period. Star B may have first been discovered by William Hershel in 1779 two years prior to discovering Uranus, while he was seeking nearby double stars for parallax studies. Star B ranges from 36 to 107 AU. It has 56% of the Sun's mass and 66% it diameter, but only 3% its luminosity. Radial velocity variations have been detected, though no planet has been announced at this time. The system is a top tier target for TPF. In Star Trek, this is home to Terra Nova.
• Xi Bootis System (G8 Ve, 21.8 ly) - Nearby binary star system, including a yellow and an orange dwarf star.
• Mu Cassiopeiae System (G5 VIp, 24.6 ly) - Nearby binary star with a Yellow Sub-Dwarf and a Red Dwarf star.
• Alula Australis System (GO-5 Ve, 27.3 ly) - Alula Australis is also known as Xi Ursae Majoris, HR 4375, and Gl 423. Its name means "southern first spring". Nearby possible quadruple star system, consisting of two yellow dwarf stars with low mass spectroscopic companions. This was the first binary star found to be orbiting each other, found by William Herschel in 1780. Star A straddles the line between a white-yellow and a yellow dwarf star, is slightly more massive, and slightly smaller than the Sun. It is thought to be about 2 Billion years old and classified as a RS Canum Venaticorum variable type star. Star A is a spectroscopic binary, with star Ab orbiting from 0.8 to 2.6 AU, making any habitable planetary orbit unstable. Star B is another yellow dwarf star, about 90% as massive and as large as the Sun. It may be orbited by a brown dwarf or low mass red dwarf (Bb) in a torch orbit. The pair is separated from Stars A by 12.5 to 39.9 AU. A fifth orange dwarf Bc component has been suspected at 450 AU, but appears not to move with the system. A second brown dwarf (T class) in the system was found in 2012 sharing the system's motion at 4000 AU.
• Mu Herculis System (G5 IV, 27.4 ly) - Mu Herculis is also known as Gl 695 and HR 6623. A Yellow Sub-Giant with up to three companion red dwarf stars. It serves as the "elbow" star in the constellation Hercules, known as "Marfak Al Jathih Al Aisr" (left elbow of kneeling man). It is also part of a Chinese asterism. Star A is also known as HD 161797. It has just a little bit more mass than the Sun and over 75% more its radius. Star B was discovered in 1781 by William Herschel and is also known as LHS 3325. Star C also exists in close coupling with star B at 11.4 AU away. Astrometric observations suggest a possible fourth red dwarf (D = Ab) exists near star A (=Aa) at 17.2 AU away. A brown dwarf or large jovian was also reported in 1994 due to astrometric effects, though this has not yet been confirmed through spectral analysis. The pair AD is 286 AU from the pair BC. The system is a member of the Wolf 630 group

Unsorted

• Chi 1 Orionis System (GO V, 28.3 ly) - Chi 1 Orionis is also called Gl 222, HR 2047, and HD 39587. Nearby binary star system. A yellow dwarf star somewhat brighter than the Sun and a red dwarf. Because the red dwarf orbits 3.3 to 8.9 AU, the chances of a habitable planet are low. A member of the Ursa Major Moving Group. There is a theory that this star may have once been in a star system that includes HD 147513 A and B (which have a planet), which is part of the same moving group. When HD 147513 B went on to become a White Dwarf, material was sluffed off onto Chi 1 Orionis A, enriching it and causing it to become a "Barium Dwarf". Gravitational instabilities caused Chi 1 Orionis and HD 147513 systems to separate.
• 41 Arae System (G8-K0 V, 28.7 ly) - 41 Arae System
• Groombridge 1830 System (G8 VIp, 29.9 ly) - Groombridge 1830 is also known as HR 4550, HD 103095, and Gl 451. Nearby dim yellow subdwarf star. It was first mentioned in Groombridge's catalog of circumpolar stars. It was found to have the highest proper motion of any star by Argelander in 1842 (replacing 61 Cygni), and is now known to have the third highest. It is likely a halo star, and has not evolved onto the main sequence despite its old age 5 or 10 billion years old. Being a halo star that does not follow the rotation of the galaxy explains its high proper motion. It is part of the Groombridge 1830 Moving Group, which consists of several other subdwarf stars. Van de Kamp recorded a flare which he assumed was a dim companion star. It has since been found to undergo superflares.
• Kappa Ceti System (G5 Ve, 29.9 ly) - Kappa Ceti is also known as Kappa 1 Ceti, HD 20630, HR 996, and Gl 137. Nearby yellow dwarf star system. Kappa 2 Ceti is nearby it in the sky, but is a giant yellow star ten times as far away. Kappa Ceti has similar mass and size as the Sun, but is cooler and less bright. It is much younger than the Sun, at 800 Million Years old. It may emit superflares, which may make life impossible on any otherwise inhabitable worlds. Past spectroscopic studies suggested a partner star, but this has not been confirmed with radial velocity studies.
• HR 4523 System (G3-5 Ve, 30.1 ly) - HR 4523 System
• 61 Ursae Majoris System (G8 Ve, 31.1 ly) - 61 UMa is also known as HR 4496, Gl 434, HD 101501, and NSV 5291. Nearby late yellow dwarf star. It is just barely visible to the naked eye. Its spectrum has been used as a stable anchor point since 1943. Its chromospheric activity suggests it younger than 500 Million Years old, but its lack of an easily observable disk suggests it is over 1 Billion years old. Lack of detection of large planets in tight orbits bodes well for finding a future habitable planet. Its variability was studied in 1953 in hopes of finding it was an eclipsing binary. It lies in the same line of sight as the sub-giant star HD 101212, though it is unclear if these are gravitationally bound or even in proximity of each other. In Star Trek, this is the system the planet Archer IV belongs to.

Orange Dwarves

• 70 Ophiuchi System (K0, 38.6 ly) - 70 Ophiuchi is also known as GJ 702 and HD 165341. It is a nearby pair of orange dwarves, easily visible with the naked eye when away from city lights. Star A is a DY Draconis variable star and is also known as HR 6752. It was first cataloged by William Herschel in the late 18th century during his study of binary stars, who claimed Father Meyor noticed its duplicity earlier (whose other claims could not be verified by contemporaries). He proved the two stars went around each other, an important verification of Newton's laws. He suspected another object was affecting the orbits of the two stars. Other astronomers claimed this could be a planet, such as Captain Jacob in 1855, which is one of the first claims for a planet using astrometric data. See also made a claim in 1899, but Moulton soon published a paper showing that this system would be unstable. In 1943, Reuyl again caused a sensation by claiming planets, only to be refuted again. The two stars follow an eccentric orbit ranging from 11.7 to 34.8 AU away. Star A has about 92% of the Sun's mass. The stars are thought to be 1.5 Billion Years old.
• Alpha Centauri System (K1, 4.2 ly) - Alpha Centauri is also known as Rigil Kentaurus. A is also known as HD 128620 and HR 5459, B is HD 128621 and HR 5460, and C is Proxima Centauri. It is the nearest star system to the Sun. Contains a yellow dwarf star a little bigger than the Sun and an orange star a little smaller orbiting each other orbiting each other about the distance Uranus is from the Sun (varies from Saturn like to Neptune like), as well as a distant Red Dwarf companion Proxima that may or may not be orbiting the other two.

    Stellar fingerprinting suggests a high probability that a planet orbits star A, due to dearth of Iron around star. Russian astronomers announced the detection of a second planet orbiting the binary pair at 80 AU with a 100 year period, which appears to be false. The stars in the system will become markedly closer together in 2016, making observations much more difficult and one follow up failed to find it. The system is the first target for the European Cheops exoplanet space telescope.

    A planet was thought to have been discovered around star B and detected by HARPS. It would have been an Earth-massed rocky-iron planet with no atmosphere at epistellar distances around the orange dwarf star B. This would have been the least massive planet found around a sunlike star. The planet was informally and controversially named by Uwingu during a fund raising naming contest Albertus Alauda, after a participant's grandfather. Earthlike planets are not detectable in the habitable zone with present radial velocity methods. Technique for detection of planet is a source of doubt for some and it has yet to be independently verified. A team thought they might have detected a transit of this planet, but further observations showed the timing wasn't consistent. It is possible that a second further out (20.4 day period) Earth-sized planet is altering the transit times of the first. A cheap crowdfunded satellite devoted to studying this star could confirm the planets. The star was observed to be a good candidate to host a "super Habitable" planet, which would have 25% more gravity than the Earth, shallow seas, flatter landscape, higher atmospheric pressure, and the 6 BYO star would be stable for life longer.

    Proxima, a small flare star, was discovered in 1915 by Robert Ines, who named it. Long suspected planet around Proxima found not to exist. The Pale Red Dot project is dedicated to finding a planet around Proxima using dopplar spectrometry. As Proxima passes in front of two stars (once in 2014, again in 2016), any planets within 5 AU should be detectable via microlensing using the HST. It is known that no planets of Neptune sized mass exist within 1 AU and no Jovians with periods up to 1000 days, or transiting planets exist. An Earth-like planet in the habitable zone was discovered around Proxima Centauri. In 2017, a large stellar flare erupted and bombarded the planet, making it likely that the atmosphere has been completely stripped away by events such as this and not a good candidate for life. It was thought that a lot of dust existed in the system, making it feasable that the star had a rich complement of planets, but this seems to not be the case.

• Epsilon Eridani System (K2, 10.4 ly) - Ran (Epsilon Eridani) is the nearest single non-red dwarf star to the Sun, also known as HD 195019, Gl 144, and HR 1084. It is a member of the Ursa Major star association and close encounters to other stars is relatively common. One of the first stars found to have a dust disk, with several potential planets suspected in the gaps early on, and later on of the earliest nearest system with confirmed planets. Has an inner asteroid belt at 3 AU, Jovian planet AEger at 3.4 AU, outer asteroid belt at 20 AU, and Kuiper Belt at 35-100 AU. A planet is proposed to be just outside the outer asteroid belt, and another just before the Kuiper belt.Because the star is very chromospherically active, doubts were cast on planet's b's existence. Hubble then confirmed its existence with astrometrics and found to be orbiting in the plane of the dust disks, which supported the theory that planets are born from dust disks and yielded a precise mass of 1.5 MJ. The planet b was originally thought to be extremely eccentric (2-10 AU), but later discovery of the inner asteroid belt suggests it is more moderately eccentric so as not to cross the belt. It could still have high eccentricity if the outer belt was being fed with material from the outer belt though. Dinosaur-killing sized impacts would be frequent on any Earth-like planets, about once every 2 million years. One of 5 PICTURE-C targets selected for sub-orbital coronograph observation. One of the first 20 exoplanet systems allowed to be given common names by the IAU. Star is named after a Norse goddess of the seas, while the planet after her husband, god of the ocean. A common sci fi system, including the original home of Star Trek Vulcans (though this moved to 40 Eridani) and Babylon 5.
• Gliese 892 System (K3, 21.2 ly) - BD+56°2966 is also known as Gl 892, HR 8832, and HD 219134. Nearby orange dwarf star and flare star. Its habitable zone is centered at 0.46 AU. It was a top tier target for the Terrestrial Planet Finder and Darwin missions. It might have a red dwarf companion.
• Gliese 570 System (K4, 19.2 ly) - Nearby star system.
• Struve 2398 System (K5, 11.4 ly) - Struve 2398 is also called Sigma 2398, BD+59°1915, DM+59°1915, and Gl 725, and informally Proxima Draconis. It is a nearby binary red dwarf system. The distance of the two component stars was first measured by Friedrich von Struve in 1832. Star A is also known as HD 173739. It is inaccurarely referred to as a K type star in some catalogs. Star B is also known as HD 173740. Their distance ranges from 19 to 65 AU. An observer from Star A would see Star B as a point about as bright as the full moon.
• Gliese 325 System (K6, 36.8 ly) - Gliese 325 System
• 61 Cygni System (K7, 11.4 ly) - 61 Cygni is also called Gl 820, very rarely called Bessel's Star, and informally Proxima Cygni. Nearby star system containing two orange dwarves. This was the star with the highest proper motion known in the 1830s and dubbed as "The Flying Star" by Giuseppe Piazzi in 1792. It is the star with the highest proper motion of any stars visible with the naked eye. In 1911, it was found by Boss to be a part of a moving group, dubbed the 61 Cygni Moving Group. Friedrich Struve first made measurements of it as a binary system in 1830. It was also the first system to have its distance measured by parallax, which was done by Bessel in 1838. The stars are barely visible with the naked eye. The stars are separated on average by 86 AU. The stars atmospheres likely do not touch. The stars are old, 6 to 10 Billion Years old. There were several claims of a planetary system in the 20th Century, but none have panned out. This includes Strand's claim in 1942 (under the direction of Van de Kamp), and Soviet claims in 1977. Heintz proved in 1978 that these claims were false. Due to its proximity to Earth, the star was a tier 1 priority for the Space Interferometry Mission, which hoped to discover planets.
• Groombridge 1618 System (K8, 16.0 ly) - Groombridge 1618 is also known as Gl 380 and HD 88230. Nearby orange dwarf system in Ursa Major. It is an unusually bright flare star, but flares less frequently than other such stars. Its level of activity suggests it is relatively young, perhaps a little older than a Billion years. First identified in A Catalog of Circumpolar Stars by Stephen Groombridge, published posthumously in 1838. An unconfirmed planet was published in 1989 with 4 Jupiter masses at about half Earth's distance, in the inner part of the star's habitability zone. It's signal could be due to stellar activity. Its closest neighbor is a red dwarf UX UMa, which would flicker in and out of visibility due to the effects of its flares.
• Gliese 750 System (K9, 51.5 ly) - Gliese 750 System

Red Dwarves

• Gliese 338 Star System (M0, 20.2 ly) - A red dwarf (A) and an orange dwarf (B). Star A is similar to Epsilon Eridani, but much dimmer and is a flare star. It was once thought to have an unseen substellar companion. It is the nearest M0 main sequence star to the Sun at 20.2 ly away.
• Groombridge 34 System (M1, 11.7 ly) - Groombridge 34 is also known as Gliese 15 and HD 1326. It is a double red dwarf star. Both are flare stars, with A being dubbed GX Andromedae and B GQ Andromedae. The stars are 147 AU apart in nearly circular orbits. Ross 248 is only 1.8 light years away. Currently the closest known multi-exoplanetary system.
• Lalande 21185 System (M2, 8.2 ly) - Lalande 21185 is also called GJ 411 and informally Proxima Ursa Majoris. It is the fourth closest star system to the Sun at 8.3 ly. It is the third brightest red dwarf in the night sky. It has been the spectral standard star for class M2 V for a long time. It is sometimes classified as a BY Draconis type variable star and has been known to emit x-rays. Van de Kamp thought he found planets in 1951. The system has two unconfirmed planets detected via radial velocity in 1996. It is also one of the earliest planets detected that still has a good chance to exist. The planets orbit far away from their dim Red Dwarf star, which makes one planet colder than Saturn and the other colder than Neptune despite being at a Saturn-like distance. One confirmed planet is a hot super earth with a rocky surface. The star is the nearest Galactic 'Thick Disk' star (which includes about 4% of nearby stars), and moves perpendicular to the galactic plane. It will get nearest to the Sun in 19,000 years when it is 4.65 ly.
• Ross 154 System (M3, 9.8 ly) - Ross 154 is also called Gliese 729 and informally Proxima Sagittarii. Nearby flare star that experiences major flares about once every 2 days. An exceptionally large red dwarf and probably young, which explains the flares. First cataloged by Frank Ross in 1925.
• Barnard's Star System (M4, 5.9 ly) - Barnard's Star is also known as Gliese 699 and informally as Proxima Ophiuchi. Named for the astronomer E. E. Barnard, who discovered it in 1916 and was the first to measure its proper motion. Second closest star system to the Sun and the one with the highest proper motion in the sky - due to its rapid approach to the Sun. Will get as close as 3.8 ly away in 12,000 years. A red dwarf thought early on to have a planet around it found due to radial velocity method, which has been disproved. A super earth has been detected at Mercury-like distances, but beyond the frost line. Life could be possible if an additional source of heat was provided. A potential target for the 1970's Project Daedelus. The star is very ancient 11-12 Billion Years Old, and is the nearest inactive Red Dwarf Star. It may take another 40 Billion Years before it cools to become a Black Dwarf. Astronomers were surprised to discover that it was a flare star in 2003, and dubbed it V2500 Ophiuchi.
• Alpha Centauri System (M5, 4.2 ly) - Alpha Centauri is also known as Rigil Kentaurus. A is also known as HD 128620 and HR 5459, B is HD 128621 and HR 5460, and C is Proxima Centauri. It is the nearest star system to the Sun. Contains a yellow dwarf star a little bigger than the Sun and an orange star a little smaller orbiting each other orbiting each other about the distance Uranus is from the Sun (varies from Saturn like to Neptune like), as well as a distant Red Dwarf companion Proxima that may or may not be orbiting the other two.

    Stellar fingerprinting suggests a high probability that a planet orbits star A, due to dearth of Iron around star. Russian astronomers announced the detection of a second planet orbiting the binary pair at 80 AU with a 100 year period, which appears to be false. The stars in the system will become markedly closer together in 2016, making observations much more difficult and one follow up failed to find it. The system is the first target for the European Cheops exoplanet space telescope.

    A planet was thought to have been discovered around star B and detected by HARPS. It would have been an Earth-massed rocky-iron planet with no atmosphere at epistellar distances around the orange dwarf star B. This would have been the least massive planet found around a sunlike star. The planet was informally and controversially named by Uwingu during a fund raising naming contest Albertus Alauda, after a participant's grandfather. Earthlike planets are not detectable in the habitable zone with present radial velocity methods. Technique for detection of planet is a source of doubt for some and it has yet to be independently verified. A team thought they might have detected a transit of this planet, but further observations showed the timing wasn't consistent. It is possible that a second further out (20.4 day period) Earth-sized planet is altering the transit times of the first. A cheap crowdfunded satellite devoted to studying this star could confirm the planets. The star was observed to be a good candidate to host a "super Habitable" planet, which would have 25% more gravity than the Earth, shallow seas, flatter landscape, higher atmospheric pressure, and the 6 BYO star would be stable for life longer.

    Proxima, a small flare star, was discovered in 1915 by Robert Ines, who named it. Long suspected planet around Proxima found not to exist. The Pale Red Dot project is dedicated to finding a planet around Proxima using dopplar spectrometry. As Proxima passes in front of two stars (once in 2014, again in 2016), any planets within 5 AU should be detectable via microlensing using the HST. It is known that no planets of Neptune sized mass exist within 1 AU and no Jovians with periods up to 1000 days, or transiting planets exist. An Earth-like planet in the habitable zone was discovered around Proxima Centauri. In 2017, a large stellar flare erupted and bombarded the planet, making it likely that the atmosphere has been completely stripped away by events such as this and not a good candidate for life. It was thought that a lot of dust existed in the system, making it feasable that the star had a rich complement of planets, but this seems to not be the case.

• Wolf 359 System (M6, 7.8 ly) - Wolf 359 is also called Gl 406, and CN Leonis and informally called Proxima Leonis. Third nearest star system to the Sun and the nearest star with no known planets. It is one of the smallest Red Dwarf stars known and is a flare star and the M6 V spectral standard star. Its proper motion was first measured by German astronomer Max Wolf in 1917. It was the lowest mass and faintest star known until the discovery of VB 10 in 1944. Its temperature is so low that chemical compounds can exist in it, which is rare for a star. It is a relatively young star, less than a billion years old.
• Wolf 424 System (M7, 14.0 ly)- Wolf 424 is also known as Gliese 473. Nearby binary Red Dwarf separated by about 2.36 to 4.19 AU with a period of 16.2 years. The secondary star is a flare star known as FL Virginis. At one point, it was thought that these could be high massed Brown Dwarves, but this has been disproven.
• TZ Arietis System (M8, 14.7 ly) - TZ Arietis is also known as L 1159-16 and Gliese 83.1. Nearby Red Dwarf flare star.
• Gliese 3849 System (M9, 34.2 ly) - Gliese 3849 System

Subdwarves

• Kapteyn's Star System (M0, 12.7 ly) - Kapteyn's Star is also known as VZ Pic, Gl 191, HD 33793, and Cordoba Zone 5 hours 243. Kapteyn noticed that a star was missing from a catalog until its new position was found. Has the second highest proper motion of any stars. Also informally called Proxima Pictoris. Nearby large and old Red Dwarf star system and nearest Halo object thought to be a remnant of the nearest and largest global cluster, Omega Centauri, which is 16,000 ly away and shredded by the Milky way 11.5 BYA, and born while that was still a separate galaxy. 2.5 times as old as the Sun and born when the Universe was only 2 BYO. Was within 3 light years of Epsilon Eridani 31,500 years ago. Will be on the other side of the galaxy in 100 MY. Is a sub-dwarf or main sequence star. Has two planets. The first is at least a 4.5 ME Super Earth (0.16 AU) and is the oldest Potentially Habitable Planet. The second is over 7 ME and beyond the HZ (0.3 AU).

See Also

• Subdwarf Stars
• Spectral Standard Stars