| Exoplanetary Scratchpad|
See also Nearby Transiting Planets.
Systems Within 10 Light Years
8.25 ly - Lalande 21185 System (3 unconfirmed planets around a red dwarf)
Systems Within 20 Light Years
10.5 ly - Epsilon Eridani System - Nearest single non-red dwarf star to the Sun and the second nearest system with a confirmed planet. The planet is a very elliptical Jupiter-like world. It also has two asteroid belts and a kuiper belt, with evidence of planets in between.
14.8 ly - Gliese 674 System - The nearest red dwarf known to have a planet which is also the third nearest confirmed exoplanet to the Sun. The planet is a Hot Neptunian in a tight orbit that has a similar eccentricity to Mercury's.
15.4 ly - Gliese 876 System - Very nearby quadruple planet system and the first Red Dwarf found to have planets. The innermost planet (d) was the first found rocky planet around a normal star (the first true Super-Earth, at epistellar distances). The outer three planets c (Saturnian), b (Jovian), and e (Neptunian) are in 1:2:4 (30d/60d/120d) resonance (the exoplanet resonance and first triple-resonant planets discovered). The outermost planet has a Mercury-like orbit however it is very much colder than Mercury. Gliese 876 e actually receives only slightly more warmth from Gliese 876 than Jupiter does from our Sun. Planet b is second discovered by ELODIE after 51 Peg b and the second to have its mass exactly measured and the first to have done so by astrometry.
16.1 ly - Gliese 832 System - Third nearest red dwarf with planets. Has a slightly eccentric Jovian planet with 64% Jupiter's mass at an asteroid-belt like distance. One of the larger red dwarf planets around one of the larger (M1.5) red dwarves (about half a Solar Mass). Has second highest angular separation from its sun. A good astrometry detection candidate and a target for SIM.
Systems Within 10 Parsecs (33 ly)
20.4 ly - Gliese 581 System - Small nearby Red Dwarf with six planets in tight circular orbits and a distant Kuiper belt where many comets orbit. Gliese 581 e was, at the time of its discovery, the smallest known dopplar-detected exoplanet and a super-Mercury, b is a hot-Neptunian, c is a super-Venus and the first detected in the habitable zone (initially heralded as habitable, but later thought too hot due to the greenhouse effect), g is a super-Earth and the first detected in the middle of the HZ (and is highly controversial, having many doubters and defenders), d is a super-Earth on the outer edge of the HZ which could support liquid water (due to its presumably large atmospheric pressure and carbon dioxide), and f (its existence is also highly controversial) is a cold super-Earth. Much further out, from 25 ± 12 AU to more than 60 AU, there is a cold debris disk reminiscent of the Kuiper belt but with 10 times more comets than the one in our solar system. The star is not very active.
23 ly - Gliese 667 System - A triple star system 23 light years away, consisting of binary of orange dwarf stars about 12 AU apart (ranging from 5 to 20 AU), around which a distant red Dwarf C orbits (ranging from 56 to 215 AU) and the nearest multiple star system known to harbor a planet. A temperate super Earth planet (5.7 ME) discovered around star C was the poster child for an announcement of 32 exoplanets discovered by European astronomers working on the HARPs project and brought the total number of exoplanets to near 400.
25.1 ly - Fomalhaut System - Fomalhaut dust disk is observed in unprecedented detail. It appears reminiscent of the "Eye of Sauron" from the Lord of the Rings films. A planet suspected of causing a sharp gap in the ring was suspected and imaged, becoming the first undisputed exoplanet imaged and the first planet since Neptune to be predicted prior to its discovery. The planet orbits about 115 AU and is between Neptune and 3x Jupiter's mass in an eccentric orbit. Planet b was shown to deviate slightly from its predicted path, stirring up some controversy about the planets' existance. Material surrounding the planet may have been imaged, rather than the planet itself, which some say should bump it off the directly imaged list. Also, the Hubble instrument that detected it is damaged and will not be fixed, making it unobservable for a time.
28 ly - 61 Virginis System - A system containing a 5.1 ME Hot Super-Earth b (which is hot enough to have emissions on its night side) and two other further out Neptunians (c and d and possibly a fourth), and a 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.
28.6 ly - Gliese 849 System - Contains the first long period exoplanet found around a red dwarf star using dopplar spectrometry. Also only the second Jupiter mass planet around a star less massive than half the Sun. Also the first confirmed Jupiter-sized planet at Neptune-like temperatures. There is evidense for a second planet.
29 ly - Gliese 433 System - Contains one of four super-Earths announced by the HARPs team in October 2009.
29.9 ly - Gliese 317 System - The smallest red dwarf within 10 parsecs with planets and the third red dwarf with detected planets. Has one eccentric long period Jovian and possibly a second very eccentric longer period Jovian in a resonant orbit.
30.7 ly - Gliese 176 System - A low-period neptunian around a nearby red dwarf. Planet is the fourth discovered Neptunian around a Red Dwarf star.
33.5 ly - Gliese 436 System - The second known red dwarf planetary system. Contains one of the first Neptunians discovered. Planet b temporarily later found to be the smallest exoplanet (about Uranus' diameter, though over 50% its mass) known to transit its host star and is currently the nearest (33 ly). Its temperature (712K) was measured to be higher than what it would be purely from radiation (520K), perhaps due to a greenhouse effect, somewhat higher than Venus. It was originally thought to have a layer of "hot ice", water solidified due to high pressures. It turned out that it was larger than thought and hot ice was not needed. It could still be a rocky super-Earth. It was later found to have a remarkably low levels of Methane and high levels of Carbon Monoxide for its 800K temperature. Possible explanations include Methane being changed into hydrocarbon polymers due to its star's ultraviolet radiation, CO being drafted upwards with winds, or observational defects. It's significant eccentricity suggests a possible neighboring planet. Planet c was announced to be the smallest known exoplanet (1.5 Earth's diameter), but was later retracted because variations in transit timing of the first planet did not occur and the proposed orbit would be unstable. It is still thought that a second planet of some kind is possible in the system.
Systems Within 50 Light Years
36.2 ly - 54 Piscium System - Nearby star with an eccentric planet. A recently discovered faint distant T type brown dwarf may be the cause of this eccentricity.
39.2 ly - Gliese 86 System - Contains the first exoplanet discovered by CORALIE of the Geneva southern extrasolar planet search programme. A cloudless blue heavy jupiter and a white dwarf around an orange star.
38.4 ly - Errai System - Primary star also known as Gamma Cephei. It is the first close in binary star found to have a planet. May contain the nearest "Sulfurous Cloud Giant" planet.
41.0 ly - HD 69830 System - First planetary system found that does not have a Jupiter-sized planet around a normal star (K0 spectrum). Contains 3 Neptunians and the first discovered asteroid belt that is like the size and age as the Sun's. The debris from this belt that was detected was from the breakup of an asteroid, is 20 times as massive as our own, and would cause zodiacal lights 1000 times brighter than we see from Earth. The smallest and outermost planet may be a 10 ME super Earth, is within the habitable zone, and is an inner shepherd for the asteroid belt. Halo 3 features a fictitious moon around this planet.
42.0 ly - 51 Pegasi System - Contains the first exo-planet around a normal star discovered and the first "Hot Jupiter" found, which is nicknamed "Bellerophon". Found to have supersonic winds that caused the eternal night-side hemisphere to be as hot as the day-side one.
42.1 ly - HD 147513 System - A jovian and white dwarf around a yellow dwarf.
43.7 ly - 55 Cancri System - Wide binary star consisting of a sun-like primary (A) and a red-dwarf secondary (B) separated by 1,100 AU, 41 light years away. Star A contains five exoplanets, the first system found with this many. It has three tightly packed eccentric planets close in to the star, including planet e (hot Super Earth/Neptunian), b (hot Jupiter), and c (hot Saturn). Planet e was the first Neptunian discovered. It was later found to be the shortest-period planet discovered (18 hours) and to transit. The planet has about half of Neptune's mass, but is Earth-like in size and density (2.17 Earth Radius). It is composed 70% of rock and the outer 30% is likely an ocean of super-critical water (between a gas and liquid state) that is 3000km thick. This is the hottest and densest super-Earth and the is the most watery planet found to date. It likely possesses a thick atmosphere of CO and CO2. The brightness of the star (also closest known to transit and only known naked eye star to do so) makes it more easily studied than other hot super Earths. Planet f is a very eccentric Saturnian in the habitable zone. Planet d is a super jovian at Jupiter-like distances, which was the first found at true Jupiter distances and still the exoplanet discovered with dopplar spectrometry with the largest known semi-major axis. The distant outer star causes planet d's axis to flip on its axis every million years. Planet d in turn causes the other planets to flip, including its star. The axis tilt of transiting planet e should be determined at some point. "Bode's law" predicts four undiscovered planets.
44.0 ly - 47 Ursa Majoris System - (aka Ursae Majoris) One of earliest systems discovered one. Planets b (2.5 MJ, 2.1 AU) and c (0.5 MJ, 3.6 AU) are in circular orbits at asteroid-belt like distances, while planet d (1.6 MJ, 11.6 AU) is in a distant more eccentric orbit. Planet b was the first found to have a circular orbit beyond the habitable zone. The discovery of planet c made the system the first multiplanet system whose planets have circular orbits. Planet d has not yet completed a full year yet since its discovery, but is the furthest out planet discovered with the dopplar spectrometry method. Studies have shown a terrestrial planet could only form in the innermost part of the habitable zone. Several transmissions have been sent to the star system.
52.0 ly - Upsilon Andromedae System - A nearby (44 ly) multi-star system which is the first multiplanet system found around a main sequence star. The main star around which the planets orbit is a yellow-white star somewhat younger than the sun and its companion is a red dwarf in a wide orbit. It is one of the most well studied non-transiting star systems. Roaster Planet b (0.05 au, 1.4 MJ, e=0.013) is nicknamed the Fire and Ice Planet because it is hot on one side and cold on the other. The hottest parts of the planet are near the trailing side terminator at the equator, due to high velocity winds transporting heat to the night side. This is 80deg offset from the starward pole and a much greater offset than other observed hot Jupiters. This threw astronomers off and caused them to doubt the wind-theory, though later observations of other planets have shown that winds indeed can travel fast enough to cause this. The middle planets c (0.83 au, 14 MJ, may actually be a brown dwarf star, e=0.224) and d (2.5 au, 10 MJ, e=0.26) have had their inclinations and masses determined with astrometry. They are very eccentric and highly inclined to each other (30 deg). Planet scattering was thought to be a source until the outermost planet was discovered. This is planet e (5.2 au, 1.05 MJ, e = 0.005), which is the most Jupiter-like exoplanet known, and is in 3:1 resonance with planet d. The star appears to have no Kuiper-belt like disc, perhaps due to its companion star sweeping away this material.
Systems Within 100 Light Years
63.4 ly - Beta Pictoris System - First star found to have a circumstellar disk and the source of most interstellar meteorites in the Solar System and the nearest star with a planet that has been visually detected (61 ly). Contains the youngest known exo-planet, which shows that Jupiter-like planets can form much quicker than previously believed. It is the closest-in exoplanet photographed and is at 8 AU and 7-11 Jupiter Masses and orbits in 20 years. This planet was first hinted at by studying dust disks in 2003 and first photographed in 2003, but it was not confirmed and was lost. It was imaged again in 2008, and became the first imaged exoplanet confirmed to move around its star in 2010. It has an effective temperature of 1,100 to 1,700C, showing that it is still warm and has retained much of its heat from its formation. Evidence of a planetary transit in 1981 was found in record. It was originally thought that a second planet must have caused a tilt in one of the disks, but now it known that the first planet is. Some data suggests the planet is unusually wide, perhaps evidence of a ring system around it. The planet is traveling through a relatively dust-free gap in the debris disk, and thought to be clearing it. The planet is losing momentum as it travels through the debris disk.
Systems Within 100 Parsecs
Systems Within 1000 Light Years
Systems Within 1000 Parsecs
Systems Within 10000 Light Years
Systems Within 10000 Parsecs
Systems Beyond 10000 Parsecs
Other Important Systems within 10 parsec
11.8 ly - Epsilon Indi System - Second nearest single sunlike star to the Sun. Orange dwarf with a binary brown dwarf orbiting it. The smaller of the two is the closest thing to an "extrasolar moon" found so far.
11.9 ly - Tau Ceti System - The nearest single G-class yellow dwarf to the sun. It has five super-Earth sized planets in orbit around it, discovered using a new and very powerful but also controversial technique, and an outer debris disk with ten times more material than our solar system's Kuiper belt has.
Two of the planets in the Tau Ceti system are located on opposite edges of a very liberally described habitable zone, analogous to Venus and Mars. No planet has as yet been detected near the middle of the habitable zone, in a situation similar to Earth.
13.2 ly - DENIS 1048-39 System - A free floating brown dwarf or red dwarf.
16.3 ly - LP 944-20 System - A free floating brown dwarf.
18.7 ly - 2MASS 0415-0935 System - A brown dwarf.
18.8 ly - Gliese 229 System - A brown dwarf around a red dwarf.
19.3 ly - Gliese 570 System - A triple star system with a brown dwarf.
26.0 ly - Vega System - Nearby star with one of the first detected circumstellar disks. Recently, it was surmised that this disk was caused by a collision between Pluto sized objects.
32.4 ly - AU Microscopii System - First red dwarf found with a circumstellar disk and the nearest planetforming disk. Also the first system where particle size in disk determined. Constraints on where planets could exist was recently published.