"with the IAU resolution. Campaigns included car bumper stickers and T-shirts. Mike Brown (the discoverer of Eris) agrees with the reduction of the number of planets to eight. NASA has announced that it will use the new guidelines established by the IAU. Alan Stern, the director of NASA's mission to Pluto, rejects the current IAU definition of planet, both in terms of defining dwarf planets as something other than a type of planet, and in using orbital characteristics (rather than intrinsic characteristics) of objects to define them as dwarf planets. Thus, in 2011, he still referred to Pluto as a"
"considered planets. On September 13, 2006, the IAU placed Eris, its moon Dysnomia, and Pluto into their Minor Planet Catalogue, giving them the official minor planet designations (134340) Pluto, (136199) Eris, and (136199) Eris I Dysnomia. Other possible dwarf planets, such as 2003 EL, 2005 FY, Sedna and Quaoar, were left in temporary limbo until a formal decision could be reached regarding their status. On June 11, 2008, the IAU executive committee announced the establishment of a subclass of dwarf planets comprising the aforementioned ""new category of trans-Neptunian objects"" to which Pluto is a prototype. This new class of objects,"
"unusual properties. The Jupiter-sized planet exhibits an unexpectedly low density, about the same as cork. This planet is dubbed HAT P-1. EV Lacertae is a rapidly spinning magnitude 10 red dwarf with a strong magnetic field. It is a flare star that can emit powerful flares potentially visible to the naked eye, thousands of times more energetic than any from Earth's sun. NGC 7243 is an open cluster 2500 light-years from Earth, visible in small amateur telescopes. It has a few dozen ""scattered"" stars, the brightest of which are of the 8th magnitude. BL Lacertae is the prototype of the"
"Jupiter. All brown dwarfs are either L dwarfs, T dwarfs or Y dwarfs, in order of decreasing temperature. An increasing number after the letter in the spectral type also means decreasing temperature, a Y2 dwarf is cooler than a Y1 dwarf is cooler than a Y0 dwarf. Planets can also be L dwarfs, T dwarfs or Y dwarfs. WISE 0535−7500 WISE J053516.80−750024.9 (designation abbreviated to WISE 0535−7500) is either a sub-brown dwarf or a free planet. It has spectral class ≥Y1 and is located in constellation Mensa. It is estimated to be 47 light-years from Earth. In 2017, more accurate"
"alcohol 2003 Sedna 2003 Psamathe 2003 Mab 2003 Perdita 2003 Cupid 2004 Orcus 2005 Makemake 2005 Eris Eris, formal designation 136199 Eris, is the largest-known dwarf planet in the Solar System and the ninth-largest body known to orbit the Sun directly. It is approximately 2,500 kilometres in diameter and 27% more massive than the dwarf planet Pluto. Eris was discovered in 2005 at W. M. Keck Observatory by American astronomer Michael E. Brown. 2005 Dysnomia Dysnomia, officially (136199) Eris I Dysnomia, is the only known moon of the dwarf planet Eris. In conjunction of finding Eris, American astronomer Michael E."
"termed plutoids, would include Pluto, Eris and any other future trans-Neptunian dwarf planets, but excluded Ceres. The IAU also determined that, for naming purposes, only those TNOs with an absolute magnitude brighter than H = +1 would be allowed into the category. To date, only two other TNOs, 2003 EL and 2005 FY, meet the absolute magnitude requirement, while other potential dwarf planets, such as Sedna, Orcus and Quaoar, do not. On July 11, 2008, the Working Group on Planetary Nomenclature included 2005 FY in the plutoid class, naming it Makemake. On September 17, 2008, 2003 EL joined the category"
"August 2011, scientists using data from NASA's Wide-field Infrared Survey Explorer (WISE) discovered six ""Y dwarfs""—star-like bodies with temperatures as cool as the human body. WISE data has revealed hundreds of new brown dwarfs. Of these, fourteen are classified as cool Ys. One of the Y dwarfs, called WISE 1828+2650, was, as of August 2011, the record holder for the coldest brown dwarf – emitting no visible light at all, this type of object resembles free-floating planets more than stars. WISE 1828+2650 was initially estimated to have an atmospheric temperature cooler than 300 K—for comparison, the upper end of room"
"dropped to the eight significantly larger bodies that had cleared their orbit (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune), and a new class of dwarf planets was created, initially containing three objects (Ceres, Pluto and Eris). There is no official definition of extrasolar planets. In 2003, the International Astronomical Union (IAU) Working Group on Extrasolar Planets issued a position statement, but this position statement was never proposed as an official IAU resolution and was never voted on by IAU members. The positions statement incorporates the following guidelines, mostly focused upon the boundary between planets and brown dwarfs: This"
"term ""planet"" was redefined to exclude the new category of dwarf planets (just as some planets had earlier been recategorised as asteroids). In 2006 Pluto, Eris, Haumea, Makemake, and (in the inner Solar System) the asteroid Ceres were reclassified as dwarf planets. Eleventh planet Eleventh planet (of the Solar System) may refer to Vesta, the eleventh object to be named a planet, later to be reclassified as an asteroid; Uranus, the eleventh planet from the Sun upon Vesta's discovery, though this was quickly superseded by new discoveries; or Haumea, which would be the eleventh planet if the classification advocated by"
"55 Cancri e 55 Cancri e (abbreviated 55 Cnc e, also named Janssen), is an exoplanet in the orbit of its Sun-like host star 55 Cancri A. The mass of the exoplanet is about 8.63 Earth masses and its diameter is about twice that of the Earth, thus classifying it as the first super-Earth discovered around a main sequence star, predating Gliese 876 d by a year. It takes less than 18 hours to complete an orbit and is the innermost known planet in its planetary system. 55 Cancri e was discovered on 30 August 2004. However, until the 2010"
"WD 1145+017 WD 1145+017 (also known as EPIC 201563164) is a white dwarf approximately from Earth in the constellation of Virgo. It is the first white dwarf to be observed with a transiting planetary-mass object orbiting it. The white dwarf has a mass of 0.6 , radius of 0.02 (1.4 ) and a temperature of 15,900 K, typical for white dwarf stars. It has been a white dwarf for 175 million years. The star included strong absorption lines due to magnesium, aluminium, silicon, calcium, iron and nickel. These elements commonly found in rocky planets are polluting the surface of the"
"TRAPPIST-1e TRAPPIST-1e, also designated as 2MASS J23062928-0502285 e, is a solid, almost Earth-sized exoplanet orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1 approximately 40 light-years (12.1 parsecs, or nearly km) away from Earth in the constellation of Aquarius. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. It was one of seven new exoplanets to be discovered orbiting the star using observations from the Spitzer Space Telescope. The exoplanet is within the star's habitable zone. Since its initial"
"Identified dwarf planets include the asteroid Ceres and the trans-Neptunian objects Pluto and Eris. In addition to these two regions, various other small-body populations, including comets, centaurs and interplanetary dust clouds, freely travel between regions. Six of the planets, at least four of the dwarf planets, and many of the smaller bodies are orbited by natural satellites, usually termed ""moons"" after the Moon. Each of the outer planets is encircled by planetary rings of dust and other small objects. The solar wind, a stream of charged particles flowing outwards from the Sun, creates a bubble-like region in the interstellar medium"
"with the unconfirmed sixth planet orbiting much further out with a period of about 41 days. K2-138b, c, d, e, and f are locked in several chains of three-body resonances, a feat shared by only a handful of systems, including TRAPPIST-1 and Kepler-80. Like the former, K2-138 could show the end result of slow, inward disk migration. K2-138 K2-138, also designated EPIC 245950175 and unofficially named EE-1, is a large early K-type main sequence star with a system of up to 6 planets discovered by citizen scientists. Four were found in the first two days of the Exoplanet Explorers project"
"31 Euphrosyne Euphrosyne (minor planet designation: 31 Euphrosyne) is the 12th-largest and the 5th-most-massive asteroid in the asteroid belt, discovered by James Ferguson on September 1, 1854. It was the first asteroid found from North America. It is named after Euphrosyne, one of the Charites in Greek mythology. It is a fairly dark body near the belt's outer edge. Consequently, Euphrosyne is never visible with binoculars, having a maximum magnitude at the best possible opposition of around +10.2, as in November 2011, which is actually fainter than any of the thirty asteroids previously discovered. It is a very little-studied body"
"Pluto Pluto (minor planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune. It was the first Kuiper belt object to be discovered. Pluto was discovered by Clyde Tombaugh in 1930 and was originally considered to be the ninth planet from the Sun. After 1992, its status as a planet was questioned following the discovery of several objects of similar size in the Kuiper belt. In 2005, Eris, a dwarf planet in the scattered disc which is 27% more massive than Pluto, was discovered. This led the International Astronomical Union (IAU) to"
"by coulomb pressure or electron degeneracy pressure. The matter of the lower limit was addressed during the 2006 meeting of the IAU's General Assembly. After much debate and one failed proposal, a large majority of those remaining at the meeting voted to pass a resolution. The 2006 resolution defines planets within the Solar System as follows: Under this definition, the Solar System is considered to have eight planets. Bodies that fulfill the first two conditions but not the third (such as Ceres, Pluto, and Eris) are classified as dwarf planets, provided they are not also natural satellites of other planets."
"Mu Arae e Mu Arae e, also known as HD 160691 e, later named Sancho, is one of the four extrasolar planets orbiting the star Mu Arae of the constellation Ara. In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the IAU announced the winning name was Sancho for this planet. The winning name was submitted by the Planetario de Pamplona, Spain. Sancho was the squire of the lead character of the novel ""El"
"Epsilon Epsilon (uppercase ', lowercase ' or lunate ; ) is the fifth letter of the Greek alphabet, corresponding phonetically to a . In the system of Greek numerals it also has the value five. It was derived from the Phoenician letter He . Letters that arose from epsilon include the Roman E, Ë and Ɛ, and Cyrillic Е, È, Ё, Є and Э. The name of the letter was originally (), but the name was changed to (""e psilon"" ""simple e"") in the Middle Ages to distinguish the letter from the digraph , a former diphthong that had come"
"Dysnomia (moon) Dysnomia (Greek: ""Δυσνομία"")—officially (136199) Eris I Dysnomia—is the only known moon of the dwarf planet Eris (the most massive known dwarf planet in the Solar System). It was discovered in 2005 by Mike Brown and the laser guide star adaptive optics team at the W. M. Keck Observatory, and carried the provisional designation of until officially named ""Dysnomia"" (from the Ancient Greek word meaning anarchy/lawlessness) after the daughter of the Greek goddess Eris. During 2005, the adaptive optics team at the Keck telescopes in Hawaii carried out observations of the four brightest Kuiper belt objects (Pluto, , ,"
"history. On March 6, 2015, the ""Dawn"" spacecraft began to orbit Ceres, becoming the first spacecraft to orbit a dwarf planet. On July 14, 2015, the ""New Horizons"" space probe flew by Pluto and its five moons. Dawn has also explored the former dwarf planet Vesta. Phoebe has been explored by Cassini (most recently) and Voyager 2, which also explored Triton. These three are thought to be former dwarf planets and therefore their exploration helps in the study of the evolution of dwarf planets. In the immediate aftermath of the IAU definition of dwarf planet, some scientists expressed their disagreement"
"name with a small Solar System body. When the definition of ""dwarf planet"" was instated at the IAU General Assembly of 2006, Ceres, Pluto and Eris were identified by name as the initial members of the dwarf planet class. However, precise regulations as to how hydrostatic equilibrium would be measured were left undefined for the time being. Without an official procedure for calculating the lower bound of size to be a ""dwarf planet"", no further bodies could be formally recognized as either dwarf planets or plutoids. It was noted that the naming process would remain stalled without such rules, and"
"sequence dwarf star stars like the Sun). In 2001, an extrasolar planet was announced by the Anglo-Australian Planet Search team, together with the planet orbiting Epsilon Reticuli. The planet, designated Mu Arae b, was thought to be in a highly eccentric orbit of around 743 days. The discovery was made by analysing variations in the star's radial velocity (measured by observing the Doppler shift of the star's spectral lines) as a result of being pulled around by the planet's gravity. Further observations revealed the presence of a second object in the system (now designated as Mu Arae e), which was"
"E E (named ""e"" , plural ""ees"") is the fifth letter and the second vowel in the modern English alphabet and the ISO basic Latin alphabet. It is the most commonly used letter in many languages, including Czech, Danish, Dutch, English, French, German, Hungarian, Latin, Latvian, Norwegian, Spanish, and Swedish. The Latin letter 'E' differs little from its source, the Greek letter epsilon, 'Ε'. This in turn comes from the Semitic letter ""hê"", which has been suggested to have started as a praying or calling human figure (""hillul"" 'jubilation'), and was probably based on a similar Egyptian hieroglyph that indicated"
"rather dim red dwarf stars that have less mass, radius, and luminosity than the Sun. Component B is spectral type M1V, component C is spectral type M3V, and both emit X-rays. On January 15, 2000, astronomers announced that they had found one of the coolest brown dwarfs then known. Catalogued as Gliese 570 D, it was observed at a wide separation of more than 1,500 astronomical unit from the triple star system. It has an estimated mass of 50 times that of Jupiter. The status of Gliese 570 D as a brown dwarf was confirmed by Doppler spectroscopy at the"
"Y0 dwarfs WISE 1405+5534 and WISE 1738+2732, which were tentatively attributed to NH (ammonia) absorption — a compelling evidence for NH absorption. The other five earliest brown dwarf discoveries from data collected by WISE: The other eight objects, checked for binarity by ""Gelino et al. (2011)"" on Keck II: WISE 0458+6434 WISEPC J045853.90+643451.9 (designation is abbreviated to WISE 0458+6434) is a binary system of two (A and B) ultracool brown dwarfs of spectral classes T8.5 and T9.5, respectively, located in constellation Camelopardalis at approximately 47 ly from Earth. WISE 0458+6434 A was discovered in 2010 by A. Mainzer ""et al."""
"""Neptune"", with Arago refraining from participating in this decision. Pluto was also considered a planet from its discovery in 1930 until its re-classification as a ""dwarf planet"" in 2006. The symbol used for Pluto was a ligature of the letters P and L (Unicode U+2647 ). In the 19th century, symbols for the major asteroids were also in use, including Vesta (an altar with fire on it; U+26B6), Juno (a sceptre; U+26B5), Ceres (a reaper's scythe; U+26B3), Pallas ( U+26B4); Encke (1850) has further symbols for Astraea, Hebe, Iris, Flora and Metis. Unicode furthermore has a symbol ( U+26B7) for"
"55 Cancri f 55 Cancri f (abbreviated 55 Cnc f), also designated Rho Cancri f and named Harriot, is an extrasolar planet approximately 41 light-years away from Earth in the constellation of Cancer (the Crab). 55 Cancri f is the fourth known planet (in order of distance) from the star 55 Cancri and the first planet to have been given the designation of ""f"". In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the"
"brown dwarf of magnitude 15.14 and spectral class M6.5V. With a proper motion of 5.1 arcseconds per year, it is the 24th closest star to Earth overall. Aries has its share of variable stars, including R and U Arietis, Mira-type variable stars, and T Arietis, a semi-regular variable star. R Arietis is a Mira variable star that ranges in magnitude from a minimum of 13.7 to a maximum of 7.4 with a period of 186.8 days. It is 4,080 light-years away. U Arietis is another Mira variable star that ranges in magnitude from a minimum of 15.2 to a maximum"
"by an attempt by the IAU division III plenary session to reinstate Pluto as a planet in a second resolution. Indeed, the draft of Resolution 5A had called these median bodies ""planetoids,"" but the plenary session voted unanimously to change the name to ""dwarf planet."" The second resolution, 5B, defined ""dwarf planets"" as a subtype of ""planet"", as Stern had originally intended, distinguished from the other eight that were to be called ""classical planets"". Under this arrangement, the twelve planets of the rejected proposal were to be preserved in a distinction between eight ""classical planets"" and four ""dwarf planets"". Resolution"
"objects discovered by Mike Brown in 2003 and 2005 respectively. However, despite having been described as a ""tenth planet"" in an early NASA press release, Eris (then known only as 2003 UB) is now classified as a dwarf planet. Only slightly more massive than Pluto, Eris has a well-determined orbit that never takes it closer to the Earth than 5.5 billion km. Sedna is slightly smaller than Pluto, and never comes closer to Earth than 11.4 billion km. Mike Brown believes the confusion results from both the real Sedna and the imaginary Nibiru having extremely elliptical orbits. Others have tied"
"to play a role in the star's ability to produce such bright flares. After the flare, the star was blue. EV Lacertae EV Lacertae (EV Lac, Gliese 873, HIP 112460) is a faint red dwarf star 16.5 light years away in the constellation Lacerta. It is the nearest star to the Sun in that region of the sky, although with an apparent magnitude of 10, it is only barely visible with binoculars. EV Lacertae is spectral type M3.5 flare star that emits X-rays. On 25 April 2008, NASA's ""Swift"" satellite picked up a record-setting flare from EV Lacertae. This flare"
"Epsilon Indi Epsilon Indi (ε Indi, ε Ind) is a star system approximately 12 light-years from Earth in the constellation of Indus consisting of a K-type main-sequence star, ε Indi A, and two brown dwarfs, ε Indi Ba and ε Indi Bb, in a wide orbit around it. The brown dwarfs were discovered in 2003. ε Indi Ba is an early T dwarf (T1) and ε Indi Bb a late T dwarf (T6) separated by 0.6 arcseconds, with a projected distance of 1460 AU from their primary star. ε Indi A has one known planet, ε Indi Ab, with a"