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For lists of Extrasolar planets, see List of stars with confirmed extrasolar planets, List of extrasolar planet extremes, and List of unconfirmed exoplanets. The following are lists of stars with confirmed Extrasolar planets. The following are lists of extremes among the known Extrasolar planets The properties listed here are those for which values are reliably known for the majority of the known sample of extrasolar This is a list of unconfirmed Extrasolar planets When a planet candidate is confirmed please remove it from this list and move it to List of stars with confirmed extrasolar planets

An extrasolar planet, or exoplanet, is a planet beyond the Solar System. A planet, as defined by the International Astronomical Union (IAU is a celestial body Orbiting a Star or stellar remnant that is The Solar System consists of the Sun and those celestial objects bound to it by Gravity. As of June 2008, 294 exoplanets have been detected and confirmed[1]. The vast majority were detected through various indirect methods rather than actual imaging. [1] Most of them are massive giant planets likely to resemble Jupiter, though this is likely to be due to limitations in detection technology. A gas giant (sometimes also known as a Jovian planet after the planet Jupiter, or giant planet) is a large Planet that is not primarily Many more recent unconfirmed detections suggest that much smaller worlds may be considerably more common than previous figures have suggested. [2]

False-color infrared image of the brown dwarf 2M1207 (blue) and its planetary companion 2M1207b (red), as viewed by the Very Large Telescope. As of September 2006 this is the only confirmed extrasolar planet to have been directly imaged.
False-color infrared image of the brown dwarf 2M1207 (blue) and its planetary companion 2M1207b (red), as viewed by the Very Large Telescope. 2M1207, 2M1207A or 2MASSW J1207334−393254 is a Brown dwarf located in the Constellation Centaurus; a companion object 2M1207b 2M1207b is a Planetary mass object orbiting the Brown dwarf 2M1207, in the constellation Centaurus, approximately 170 Light-years The Very Large Telescope ( VLT) is a system of four separate Optical telescopes (the Antu telescope, the Kueyen telescope, the Melipal As of September 2006 this is the only confirmed extrasolar planet to have been directly imaged. September 2006 was marked by a controversy surrounding statements made by Pope Benedict XVI regarding Islam, during the same week as the fifth anniversary

Extrasolar planets became a subject of scientific investigation in the mid-19th century. Astronomers generally supposed that some existed, but it was not known how common they were and how similar they were to the planets of the Solar System. Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study The first confirmed detections were made in the 1990s; since 2000, more than 15 have been discovered every year. The frequency of detection is increasing with 61 planets detected in 2007. It is estimated that at least 10% of sun-like stars have planets, and the true proportion may be much higher. The Sun (Sol is the Star at the center of the Solar System. [3] The discovery of extrasolar planets sharpens the question of whether some might support extraterrestrial life. Extraterrestrial life is Life originating outside of the Earth. [4]

Currently Gliese 581 d, the third planet of the red dwarf star Gliese 581 (approximately 20 light years from Earth), appears to be the best example yet discovered of a possible terrestrial exoplanet which orbits close to the habitable zone of space surrounding its star. Gliese 581 d (ˈgliːzə is an Extrasolar planet approximately 20 Light-years away in the Constellation of Libra. According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool Star, of the Main sequence, either late K Gliese 581 (ˈgliːzə is a Red dwarf Star with spectral type M3V located 20 A light-year or light year (symbol ly) is a unit of Length, equal to just under ten trillion Kilometres As defined by EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 A terrestrial planet, telluric planet or rocky planet is a Planet that is primarily composed of Silicate rocks Within our In Astronomy a habitable zone ( HZ) is a region of space where conditions are favorable for Life as it may be found on Earth. Going by strict terms, it appears to reside outside the "Goldilocks Zone", but the greenhouse effect may raise the planet's surface temperature to that which would support liquid water. In Astronomy a habitable zone ( HZ) is a region of space where conditions are favorable for Life as it may be found on Earth. The Greenhouse effect refers to the change in the Thermal equilibrium temperature of a planet or moon by the presence of an Atmosphere containing gas that absorbs

Contents

History of detection

Retracted discoveries

Unconfirmed until 1988, extrasolar planets have long been assumed as plausible, and speculation on planets circling around the fixed stars dates to at least the early 18th century, with Isaac Newton's General Scholium (1713), which has "And if the fixed Stars are the centers of other like systems, these, being form'd by the like wise counsel, must be all subject to the dominion of One" (trans. Sir Isaac Newton, FRS (ˈnjuːtən 4 January 1643 31 March 1727) Biography Early years See also Isaac Newton's early life and achievements The Philosophiæ Naturalis Principia Mathematica ( Latin: "mathematical principles of natural philosophy" often Principia Motte 1729).

Our solar system compared with the system of 55 Cancri
Our solar system compared with the system of 55 Cancri

Claims about detection of exoplanets have been made from the 19th century. 55 Cancri (ˈkæŋkraɪ or /ˈkæŋkriː/ also catalogued Rho1 Cancri or abbreviated 55 Cnc, is a Binary star approximately 41 Light-years Some of the earliest involve the binary star 70 Ophiuchi. A binary star is a Star system consisting of two Stars orbiting around their Center of mass. 70 Ophiuchi is a binary Star system 166 Light years away from Earth. In 1855, Capt. W. S. Jacob at the East India Company's Madras Observatory reported that orbital anomalies made it "highly probable" that there was a "planetary body" in this system. The Honourable East India Company ( HEIC) referred to most commonly as the East India Company, also historically and colloquially as John Company, or The Madras Observatory was founded by the British East India Company in 1786 in Chennai (then Madras [5] In the 1890s, Thomas J. J. See of the University of Chicago and the United States Naval Observatory stated that the orbital anomalies proved the existence of a dark body in the 70 Ophiuchi system with a 36-year period around one of the stars. Thomas Jefferson Jackson (T J J See, (1866 to July 4 1962 was an American Astronomer (born near Montgomery City, Missouri) who received The University of Chicago is a Private university located principally in the Hyde Park neighborhood of Chicago. The United States Naval Observatory ( USNO) is one of the oldest Scientific agencies in the United States. The orbital period is the time taken for a given object to make one complete Orbit about another object [6] However, Forest Ray Moulton soon published a paper proving that a three-body system with those orbital parameters would be highly unstable. Forest Ray Moulton ( April 29, 1872 &ndash December 7, 1952) was a U [7] During the 1950s and 1960s, Peter van de Kamp of Swarthmore College made another prominent series of detection claims, this time for planets orbiting Barnard's Star. Piet Van de Kamp (December 26 1901 Kampen &ndash May 18 1995 known as Peter van de Kamp in the United States, was a Dutch Astronomer Swarthmore College is a private, independent, liberal arts college in the United States with an enrollment of about 1500 students Barnard's Star ( is a very low-mass Red dwarf Star approximately 6 Light-years away in the Constellation of Ophiuchus (the [8] Astronomers now generally regard all the early reports of detection as erroneous.

In 1991, Andrew Lyne, M. Andrew G Lyne FRS (born 1942 is a British Physicist. Lyne is Langworthy Professor of Physics in the School of Physics and Astronomy University of Bailes and S. L. Shemar claimed to have discovered a pulsar planet in orbit around PSR 1829-10, using pulsar timing variations. Pulsar planets are Planets that are found orbiting Pulsars or rapidly rotating Neutron stars The first such planet to be discovered was Any Planet is an extremely faint light source compared to its parent Star. [9] The claim briefly received intense attention, but Lyne and his team soon retracted it. [10]

Our inner solar system superimposed behind the orbits of the planets HD 179949 b, HD 164427 b, Epsilon Reticuli Ab, and Mu Arae b (all parent stars are in the center)
Our inner solar system superimposed behind the orbits of the planets HD 179949 b, HD 164427 b, Epsilon Reticuli Ab, and Mu Arae b (all parent stars are in the center)

Published discoveries

The first published discovery to have received subsequent confirmation was made in 1988 by the Canadian astronomers Bruce Campbell, G. HD 179949 is a 6th magnitude Star in the Constellation of Sagittarius. 164427 is a Star in Telescopium constellation with a Brown dwarf companion discovered in 2001 taking place in Australia. Epsilon Reticuli (in the literature HD 27442) is a binary system approximately 59 Light-years away in the Constellation of Reticulum Mu Arae (μ Ara / μ Arae often cataloged as HD 160691, is a Yellow subgiant Star approximately 50 Light-years away in the A. H. Walker, and S. Yang. [11] Their radial-velocity observations suggested that a planet orbited the star Gamma Cephei. Gamma Cephei (γ Cep / γ Cephei traditionally named Errai, Er Rai, and or Alrai, is a binary star system approximately 45 Light-years They remained cautious about claiming a true planetary detection, and widespread skepticism persisted in the astronomical community for several years about this and other similar observations. It was mainly because the observations were at the very limits of instrumental capabilities at the time. Another source of confusion was that some of the possible planets might instead have been brown dwarfs, objects that are intermediate in mass between planets and stars. Brown dwarfs are sub- stellar objects with a mass below that necessary to maintain Hydrogen -burning Nuclear fusion reactions in their cores as do stars

The following year, additional observations were published that supported the reality of the planet orbiting Gamma Cephei,[12] though subsequent work in 1992 raised serious doubts. [13] Finally, in 2003, improved techniques allowed the planet's existence to be confirmed. [14]

In early 1992, radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of planets around another pulsar, PSR 1257+12. Aleksander Wolszczan (alɛk'sandɛr 'vɔlʂt͡ʂan) ( Apr 29 1946 in Szczecinek, Poland) is a Polish astronomer. Dale A Frail is a Canadian radio Astronomer working for the National Radio Astronomy Observatory (NRAO in Socorro New Mexico. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves [15] This discovery was quickly confirmed, and is generally considered to be the first definitive detection of exoplanets. These pulsar planets are believed to have formed from the unusual remnants of the supernova that produced the pulsar, in a second round of planet formation, or else to be the remaining rocky cores of gas giants that survived the supernova and then spiraled into their current orbits. A supernova (plural supernovae or supernovas) is a stellar Explosion. A gas giant (sometimes also known as a Jovian planet after the planet Jupiter, or giant planet) is a large Planet that is not primarily

On October 6, 1995, Michel Mayor and Didier Queloz of the University of Geneva announced the first definitive detection of an exoplanet orbiting an ordinary main-sequence star (51 Pegasi). Events 105 BC - Battle of Arausio: The Cimbri inflict the heaviest defeat on the Roman army of Gnaeus Mallius Maximus Year 1995 ( MCMXCV) was a Common year starting on Sunday. Events of 1995 Michel G E Mayor (born 12 January, 1942) is a Swiss professor in the Department of Astronomy at the University of Geneva. Didier Queloz (born February 23 1966) is a Geneva -based Astronomer with a prolific record in finding Extrasolar planets He is understudy The University of Geneva (Université de Genève is a university in Geneva, Switzerland. The main sequence is the name for a continuous and distinctive band of stars that appear on a plot of stellar color versus brightness 51 Pegasi is a Sun -like star (although somewhat older than the Sun located 15 [16] This discovery was made at the Observatoire de Haute-Provence and ushered in the modern era of exoplanetary discovery. The Observatoire de Haute-Provence (OHP Haute-Provence Observatory in English was established in 1937 as a national facility for French Astronomers Technological advances, most notably in high-resolution spectroscopy, led to the detection of many new exoplanets at a rapid rate. Spectroscopy was originally the study of the interaction between Radiation and Matter as a function of Wavelength (λ These advances allowed astronomers to detect exoplanets indirectly by measuring their gravitational influence on the motion of their parent stars. Gravitation is a natural Phenomenon by which objects with Mass attract one another Several extrasolar planets were eventually also detected by observing the variation in a star's apparent luminosity as a planet passed in front of it.

To date, 294 exoplanets have been found,[1] including a few that were confirmations of controversial claims from the late 1980s. The first system to have more than one planet detected was υ And. Upsilon Andromedae (υ Andromedae / υ And is a Binary star located approximately 44 Light-years away in the Constellation Andromeda. Twenty such multiple-planet systems are now known. Among the known exoplanets are four pulsar planets orbiting two separate pulsars. Infrared observations of circumstellar dust disks also suggest the existence of millions of comets in several extrasolar systems. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of A comet is a small Solar System body that orbits the Sun and when close enough to the Sun exhibits a visible coma (atmosphere or a tail —

Detection methods

Main article: Methods of detecting extrasolar planets

Planets are extremely faint light sources compared to their parent stars. Any Planet is an extremely faint light source compared to its parent Star. At visible wavelengths, they usually have less than a millionth of their parent star's brightness. In addition to the intrinsic difficulty of detecting such a faint light source, the parent star causes a glare that washes it out.

For those reasons, current telescopes can only directly image exoplanets under exceptional circumstances. A telescope is an instrument designed for the observation of remote objects and the collection of Electromagnetic radiation. Any Planet is an extremely faint light source compared to its parent Star. Specifically, it may be possible when the planet is especially large (considerably larger than Jupiter), widely separated from its parent star, and hot so that it emits intense infrared radiation.

The vast majority of known extrasolar planets have been discovered through indirect methods:

Diagram showing how an exoplanet orbiting a larger star could produce changes in position and velocity of the star as they orbit their common center of mass.
Diagram showing how an exoplanet orbiting a larger star could produce changes in position and velocity of the star as they orbit their common center of mass.

Not counting a few exceptions, all known extrasolar planet candidates have been found using ground-based telescopes. However, many of the methods can yield better results if the observing telescope is located above the restless atmosphere. COROT (launched in December, 2006) is the only active space mission dedicated to extrasolar planet search. COROT ( CO nvection RO tation and planetary T ransits is a space mission led by the French Space Agency (CNES in conjunction with the European Hubble Space Telescope has also found or confirmed a few planets. The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into There are many planned or proposed space missions such as Kepler, New Worlds Mission, Darwin, Space Interferometry Mission, Terrestrial Planet Finder, and PEGASE. The Kepler Mission is a Space Photometer being developed by NASA. The New Worlds Mission is a project funded by NASA Institute for Advanced Concepts (NIAC headed by Dr The Darwin Mission is a proposed European Space Agency (ESA program designed to directly detect Earth -like planets orbiting nearby stars, and search for The Space Interferometry Mission, also known as SIM PlanetQuest, is a planned space telescope being developed by the U The Terrestrial Planet Finder ( TPF) was a plan by the National Aeronautics and Space Administration of the United States for a Telescope PEGASE is a proposed space mission to build a double-aperture Interferometer composed of three free-flying Satellites The goal of the mission is the study of

Nomenclature

A lower-case letter is placed after the star name, starting with "b" for the first planet found in the system (for example, 51 Pegasi b). 51 Pegasi b, also unofficially named Bellerophon and or abbreviated as 51 Peg b, is an Extrasolar planet approximately 50 Light-years The next planet is labeled, for example, as "51 Pegasi c", the one following that "51 Pegasi d", and so on. The suffix "a" was intended to refer specifically to the primary, as opposed to the system as a whole, but this did not catch on.

Note that the letters assigned are based on the order in which the planets are discovered, and not on their position. For example, in the Gliese 876 system, the most recently discovered planet is referred to as Gliese 876 d, despite the fact that it is closer to the star than Gliese 876 b and Gliese 876 c. Gliese 876, also catalogued as IL Aquarii, is a Red dwarf Star approximately 15 Light-years away in the Constellation of Gliese 876 d, also cataloged as IL Aquarii d, is an Extrasolar planet approximately 15 Light-years away in the Constellation of Aquarius Gliese 876b is an Extrasolar planet Orbiting the Red dwarf Star Gliese 876 every 60 Gliese 876c is an Extrasolar planet Orbiting the Red dwarf Star Gliese 876, taking 30 Nomenclatures often used in science fiction used Roman numerals in the order of planets' positions from the star, but for the above reason, this is not practical. Roman numerals are a Numeral system originating in ancient Rome, adapted from Etruscan numerals.

Before the discovery of 51 Pegasi b in 1995, extrasolar planets were named differently. The first extrasolar planets found around pulsar PSR 1257+12 were named with capital letters: PSR 1257+12 B and PSR 1257+12 C. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves When a new, closer-in exoplanet was found around the pulsar, it was named PSR 1257+12 A, not D. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves

Some of the extrasolar planets have unofficial nicknames, as well. For example, HD 209458 b is sometimes called "Osiris," and 51 Pegasi b is called "Bellerophon. HD 209458 b, also unofficially named Osiris, is an Extrasolar planet that orbits the Solar twin Star HD 209458 in the constellation 51 Pegasi b, also unofficially named Bellerophon and or abbreviated as 51 Peg b, is an Extrasolar planet approximately 50 Light-years " Gliese 581 c, the smallest and most Earth-like planet around main-sequence stars, has been called "Ymir. Gliese 581 c (ˈgliːzə is a " Super-earth " "[18] The IAU currently has no plans to officially name extrasolar planets, considering it impractical. [19]

Definition

Main article: Definition of planet

According to the International Astronomical Union's working definition of "planet," a planet must orbit a star. From its beginnings denoting the "wandering stars" of the classical world the definition of " Planet " has been fraught with ambiguity A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth [20] However, the current IAU definition for planet only accounts for our own solar system and all extrasolar planets were excluded from this definition for now. [21] There have also been reports of free-floating planetary-mass objects (ones not orbiting any star), sometimes called "rogue planets" or "interstellar planets". A planemo is a celestial object with mass greater than that of an irregularly shaped asteroid yet smaller than a nuclear reactive Brown dwarf or Star. A rogue planet is an object which has equivalent mass to a Planet and is not gravitationally bound to any Star, and that therefore moves through space as Such objects are not discussed in this article since they are outside the working definition of "planet". For more information, see rogue planet. A rogue planet is an object which has equivalent mass to a Planet and is not gravitationally bound to any Star, and that therefore moves through space as

General properties

Stellar characteristics

Most known exoplanets orbit stars roughly similar to our own Sun, that is, main-sequence stars of spectral categories F, G, or K. The Sun (Sol is the Star at the center of the Solar System. The main sequence is the name for a continuous and distinctive band of stars that appear on a plot of stellar color versus brightness In Astronomy, stellar classification is a classification of Stars based initially on photospheric temperature and its associated Spectral characteristics One reason is simply that planet search programs have tended to concentrate on such stars. But even after taking this into account, statistical analysis suggests that lower-mass stars (red dwarfs, of spectral category M) are either less likely to have planets or have planets that are themselves of lower mass and hence harder to detect. According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool Star, of the Main sequence, either late K In Astronomy, stellar classification is a classification of Stars based initially on photospheric temperature and its associated Spectral characteristics [22] Recent observations by the Spitzer Space Telescope indicate that stars of spectral category O, which are much hotter than our Sun, produce a photo-evaporation effect that inhibits planetary formation. The Spitzer Space Telescope (formerly the Space Infrared Telescope Facility, SIRTF) is an Infrared Space observatory. In Astronomy, stellar classification is a classification of Stars based initially on photospheric temperature and its associated Spectral characteristics Photoevaporation denotes the process when a Planet is stripped of its Atmosphere (or parts of the atmosphere due to high energy Photons and other [23]

Stars are composed mainly of the light elements hydrogen and helium. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical They also contain a small fraction of heavier elements such as iron, and this fraction is referred to as a star's metallicity. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 In Astronomy and Physical cosmology, the metallicity of an object is the proportion of its matter made up of Chemical elements other than Hydrogen Stars of higher metallicity are much more likely to have planets, and the planets they have tend to be more massive than those of lower-metallicity stars. [3]

In careful spectroscopic observations it is found that rotational velocity drops off abruptly after spectral class F2 stars. It should be noted that the Sun is a G2 Class star (which is, after F2. ) Ninety eight percent of the angular momentum of the solar system derives from the orbital motions of the planets. In an isolated system, angular momentum must be conserved, so, of course, the remaining 2 percent lies with the sun. Therefore it seems that the angular momentum of the Sun has been transferred to the planets, that would otherwise cause the Sun to rotate 50 times faster than it currently does (approximately 2 km/sec. ) If this hypothesis is correct, slowly rotating stars are so because a large portion of their angular momentum has been transferred elsewhere, perhaps to orbiting planets. Since ninety three percent of all main sequence stars are later than F2, it would seem that the bulk of stars in the galaxy may have planets, unless alternative methods of angular momentum transfer are proven likely.

Measured properties

Most known extrasolar planet candidates have been discovered using indirect methods and therefore only certain physical and orbital parameters can be determined. The radial velocity method provides all orbital elements except for inclination, including orbital period, semi-major axis, eccentricity, angular distance, longitude of periastron, time of periastron, and semi-amplitude. The elements of an orbit are the parameters needed to specify that Orbit uniquely given a model of two point-masses obeying the Newtonian laws of motion and the Inclination in general is the Angle between a Reference plane and another plane or axis of direction The orbital period is the time taken for a given object to make one complete Orbit about another object In Geometry, the semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolae In Mathematics (in particular Geometry and Trigonometry) and all Natural sciences (including astronomy geophysics etc the angular distance In Astrodynamics, the longitude of the periapsis (symbolized \varpi of an orbiting body is the Longitude (measured from the point of the vernal equinox The unknown inclination results in unknown mass and therefore usually only the minimum mass is given. The term minimum mass refers to the detected objects with a lower-bound calculated Mass. In some cases it may be a much more massive object such as brown dwarf or red dwarf star instead. However, if the planet's orbit is nearly perpendicular to sky (inclination close to 90°), the planet can be seen transiting its star and therefore its true mass and radius can be measured. Inclination in general is the Angle between a Reference plane and another plane or axis of direction The term true mass is synonymous with the term Mass, but is used in Astronomy to differentiate the measured mass of a planet from the lower limit of mass usually obtained Furthermore, astrometric observations and dynamical studies in multiple planet systems can be used to constrain the mass of a planet.

Spectroscopic measurements during the transit can be used to study a transiting planet's atmospheric composition. [24] Secondary transit (occurs when the planet is behind the star) can be used for direct detection of infrared radiation from the planet. In addition, infrared observations can be used to study heat patterns on the surface of a closely-orbiting planet.

Selection effect

All extrasolar planets discovered by radial velocity (blue dots), transit (red) and microlensing (yellow) to 31 August 2004. Also shows detection limits of forthcoming space- and ground-based instruments.
All extrasolar planets discovered by radial velocity (blue dots), transit (red) and microlensing (yellow) to 31 August 2004. Events 1056 - Byzantine Empress Theodora becomes ill dying suddenly a few days later without children to succeed the Throne "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " Also shows detection limits of forthcoming space- and ground-based instruments.

The vast majority of exoplanets found so far have high masses. All but six of them have more than ten times the mass of Earth. Many are considerably more massive than Jupiter, the most massive planet in the Solar System. The Solar System consists of the Sun and those celestial objects bound to it by Gravity. However, these high masses are in large part due to an observational selection effect: all detection methods are much more likely to discover massive planets. Selection bias is a distortion of evidence or data that arises from the way that the data are collected This bias makes statistical analysis difficult, but it appears that lower-mass planets are actually more common than higher-mass ones, at least within a broad mass range that includes all giant planets. In addition, the fact that astronomers have found several planets only a few times more massive than Earth, despite the great difficulty of detecting them, indicates that such planets are fairly common. [3]

Many exoplanets orbit much closer around their parent star than any planet in our own Solar System orbits around the Sun. Again, that is mainly an observational selection effect. The radial-velocity method is most sensitive to planets with such small orbits. Astronomers were initially very surprised by these "hot Jupiters," but it is now clear that most exoplanets (or at least, most high-mass exoplanets) have much larger orbits, some located in habitable zones where suitable for liquid water and life. Hot Jupiters (also called roasters, epistellar jovians, pegasids or pegasean planets) are a class of Extrasolar planets whose It appears plausible that in most exoplanetary systems, there are one or two giant planets with orbits comparable in size to those of Jupiter and Saturn in our own Solar System.

The eccentricity of an orbit is a measure of how elliptical (elongated) it is. In Astrodynamics, under standard assumptions, any Orbit must be of Conic section shape Most known exoplanets have quite eccentric orbits. This is not an observational selection effect, since a planet can be detected about a star equally well regardless of the eccentricity of its orbit. The prevalence of elliptical orbits is a major puzzle, since current theories of planetary formation strongly suggest planets should form with circular (that is, non-eccentric) orbits. One possible theory is that small companions such as T dwarfs (methane-bearing brown dwarfs) can hide in such solar systems and can cause the orbits of planets to be extreme. Brown dwarfs are sub- stellar objects with a mass below that necessary to maintain Hydrogen -burning Nuclear fusion reactions in their cores as do stars [25] This is also an indication that our own Solar System may be unusual, since all of its planets except for Mercury do follow basically circular orbits. [3]

Unanswered questions

This planetary habitability chart shows where life might exist on extrasolar planets based on our own Solar System and life on Earth.
This planetary habitability chart shows where life might exist on extrasolar planets based on our own Solar System and life on Earth. Planetary habitability is the measure of a Planet 's or a Natural satellite 's potential to develop and sustain Life. The Solar System consists of the Sun and those celestial objects bound to it by Gravity. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001

Many unanswered questions remain about the properties of exoplanets, such as the details of their composition and the likelihood of possessing moons. An extrasolar moon, or exomoon, is a term that refers to a smaller natural (non-man-made Satellite The recent discovery that several surveyed exoplanets lacked water showed that there is still much more to be learned about the properties of exoplanets. Another question is whether they might support life. Several planets do have orbits in their parent star's habitable zone, where it should be possible for Earth-like conditions to prevail. Most of those planets are giant planets more similar to Jupiter than to Earth; if these planets have large moons, the moons might be a more plausible abode of life. Detection of life (other than an advanced civilization) at interstellar distances, however, is a tremendously challenging technical task that will not be feasible for many years, even if such life is commonplace.

Notable extrasolar planets

First discoveries

The first milestone in the discovery of extrasolar planets was in 1992, when Wolszczan and Frail published results in the journal Nature indicating that pulsar planets existed around PSR B1257+12. Nature is a prominent Scientific journal, first published on 4 November 1869 Pulsar planets are Planets that are found orbiting Pulsars or rapidly rotating Neutron stars The first such planet to be discovered was PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. [15] Wolszczan had discovered the millisecond pulsar in question in 1990 at the Arecibo radio observatory. Aleksander Wolszczan (alɛk'sandɛr 'vɔlʂt͡ʂan) ( Apr 29 1946 in Szczecinek, Poland) is a Polish astronomer. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves The Arecibo Observatory is a very sensitive Radio telescope located approximately south-southwest from the town of Arecibo in Puerto Rico. These were the first exoplanets ever verified, and they are still considered highly unusual in that they orbit a pulsar. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves

The first verified discovery of an exoplanet (51 Pegasi b) orbiting a main sequence star (51 Pegasi) was announced by Michel Mayor and Didier Queloz in Nature on October 6, 1995. 51 Pegasi b, also unofficially named Bellerophon and or abbreviated as 51 Peg b, is an Extrasolar planet approximately 50 Light-years The main sequence is the name for a continuous and distinctive band of stars that appear on a plot of stellar color versus brightness 51 Pegasi is a Sun -like star (although somewhat older than the Sun located 15 Michel G E Mayor (born 12 January, 1942) is a Swiss professor in the Department of Astronomy at the University of Geneva. Didier Queloz (born February 23 1966) is a Geneva -based Astronomer with a prolific record in finding Extrasolar planets He is understudy [16] Astronomers were initially surprised by this "hot Jupiter" but soon set out to find other similar planets with great success.

Other notable discoveries

Since that time, other notable discoveries have included:

1996, 47 Ursae Majoris b
This Jupiter-like planet was the first long-period planet discovered, orbiting at 2. 47 Ursae Majoris b is an Extrasolar planet approximately 46 Light-years away in the Constellation of Ursa Major. 11 AU from the star with the eccentricity of 0. 049. There is second companion, initially claimed to orbit some further out, at 3. 79 AU. [26] However, the original parameters for the second planet was disproven in 2006, it is now claimed to orbit even further from the star, at 7. 73 AU, with the eccentricity of 0. 005. Now it is confirmed that this planet orbits at 3. 39 AU with the eccentricity of 0. 220 ± 0. 028 and a period of 2190 ± 460 days.
1998, Gliese 876 b
The first planet found that orbits around a red dwarf star (Gliese 876). Gliese 876b is an Extrasolar planet Orbiting the Red dwarf Star Gliese 876 every 60 According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool Star, of the Main sequence, either late K Gliese 876, also catalogued as IL Aquarii, is a Red dwarf Star approximately 15 Light-years away in the Constellation of It orbits closer to the star than Mercury is to the Sun. The Sun (Sol is the Star at the center of the Solar System. More planets have subsequently been discovered closer to the star. [27]
1999, Upsilon Andromedae
The first multiple-planetary system to be discovered around a main sequence star. Upsilon Andromedae (υ Andromedae / υ And is a Binary star located approximately 44 Light-years away in the Constellation Andromeda. The main sequence is the name for a continuous and distinctive band of stars that appear on a plot of stellar color versus brightness It contains three planets, all are Jupiter-like. Planets b, c, d are announced in 1996, 1999, and 1999 respectively. Upsilon Andromedae b, occasionally referred to as Upsilon Andromedae Ab (to distinguish it from the Red dwarf Star Upsilon Andromedae B Upsilon Andromedae c is an Extrasolar planet Orbiting the Sun -like Star Upsilon Andromedae A every 241 Upsilon Andromedae d is an Extrasolar planet orbiting the Sun -like Star Upsilon Andromedae A. Their masses are 0. 687, 1. 97, and 3. 93 MJ; they orbit at 0. 0595, 0. 830, and 2. 54 AU respectively. [28]
1999, HD 209458 b
This exoplanet, originally discovered with the radial-velocity method, became the first exoplanet to be seen transiting its parent star. HD 209458 b, also unofficially named Osiris, is an Extrasolar planet that orbits the Solar twin Star HD 209458 in the constellation The transit detection conclusively confirmed the existence of the planets suspected to be responsible for the radial velocity measurements. [29]
2001, HD 209458 b
Astronomers using the Hubble Space Telescope announced that they had detected the atmosphere of HD 209458 b. HD 209458 b, also unofficially named Osiris, is an Extrasolar planet that orbits the Solar twin Star HD 209458 in the constellation The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into They found the spectroscopic signature of sodium in the atmosphere, but at a smaller intensity than expected, suggesting that high clouds obscure the lower atmospheric layers. Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 [30]
2001, Iota Draconis b
The first planet discovered around the giant star. Iota Draconis b was discovered in 2001 during a Radial velocity study of K-class giant stars and was the first planet discovered orbiting a Giant star A giant star is a Star with substantially larger Radius and Luminosity than a Main sequence star of the same surface temperature. It is an orange giant. A giant star is a Star with substantially larger Radius and Luminosity than a Main sequence star of the same surface temperature. This provides evidence for a survival and behavior of planetary systems around giant stars. Giant stars have pulsations that can mimic the presence of planets. Do not confuse with Angular velocity In Physics (specifically Mechanics and Electrical engineering) angular frequency The planet is very massive and has a very eccentric orbit. It orbits the average distance of 27. 5% further from its star than Earth to the Sun. [31]
Artist's impression of the pulsar planet PSR B1620-26c (discovered in 2003); it is over 12.5 billion years old, making it the oldest known extrasolar planet.
Artist's impression of the pulsar planet PSR B1620-26c (discovered in 2003); it is over 12. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves 5 billion years old, making it the oldest known extrasolar planet.
2003, PSR B1620-26c
On July 10, using information obtained from the Hubble Space Telescope, a team of scientists led by Steinn Sigurdsson confirmed the oldest extrasolar planet yet. Events 48 BC - Battle of Dyrrhachium, Julius Caesar barely avoids a catastrophic defeat to Pompey in Macedonia. The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into The planet is located in the globular star cluster M4, about 5,600 light years from Earth in the constellation Scorpius. Star clusters are groups of Stars which are gravitationally bound Messier 4 (also known as M4 or NGC 6121) is a Globular cluster in the Constellation Scorpius. In common usage a constellation is a group of celestial bodies that are connected together in some arrangement typically stars to form a visible figure or picture Scorpius ( Latin for Scorpion, symbol, Unicode ♏ is one of the Constellations of the Zodiac. This is the only planet known to orbit around a stellar binary; one of the stars in the binary is a pulsar and the other is a white dwarf. A binary star is a Star system consisting of two Stars orbiting around their Center of mass. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves A white dwarf, also called a degenerate dwarf, is a small Star composed mostly of Electron-degenerate matter. The planet has a mass twice that of Jupiter, and is estimated to be 13 billion years old. [32]
2004, Mu Arae d
In August, a planet orbiting Mu Arae with a mass of approximately 14 times that of the Earth was discovered with the European Southern Observatory's HARPS spectrograph. Mu Arae d is an Extrasolar planet orbiting the star Mu Arae. The planet has a mass about half that of Jupiter and orbits at a Distance Mu Arae (μ Ara / μ Arae often cataloged as HD 160691, is a Yellow subgiant Star approximately 50 Light-years away in the Spectrograph is in a state of flux do not create Echelle spectrograph until we know where to redirect to probably Spectrography#Echelle spectrograph -->The A spectrometer is an Optical instrument used to measure properties of Light over a specific portion of the Electromagnetic spectrum, typically used Depending on its composition, it is the first published "hot Neptune" or "super-Earth". [33]
Infrared image of 2M1207 (bluish) and 2M1207b (reddish). The two objects are separated by less than one arc second in Earth's sky. Image taken using the ESO's 8.2 m Yepun VLT.
Infrared image of 2M1207 (bluish) and 2M1207b (reddish). The two objects are separated by less than one arc second in Earth's sky. A minute of arc, arcminute, or MOA is a unit of angular measurement, equal to one sixtieth (1/60 of one degree. Image taken using the ESO's 8. 2 m Yepun VLT. The Very Large Telescope ( VLT) is a system of four separate Optical telescopes (the Antu telescope, the Kueyen telescope, the Melipal
2004, 2M1207 b
The first planet around a brown dwarf. 2M1207b is a Planetary mass object orbiting the Brown dwarf 2M1207, in the constellation Centaurus, approximately 170 Light-years Brown dwarfs are sub- stellar objects with a mass below that necessary to maintain Hydrogen -burning Nuclear fusion reactions in their cores as do stars The planet is also the first to be directly imaged (in infrared). Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of It has 5 Jupiter mass while other estimates give a slightly lower mass. It orbits at 55 AU from the brown dwarf. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the The brown dwarf mass is only 25 Jupiters. The temperature of gas giant planet is very hot (1250 K), mostly due to gravitational contraction. A gas giant (sometimes also known as a Jovian planet after the planet Jupiter, or giant planet) is a large Planet that is not primarily [34] In late 2005, the parameters changed to 41 AU and has mass of 3. 3 Jupiters as a result that the star is closer to Earth than it was originally expected. In 2006, the dust disk was found around 2M1207, providing evidence for a planet formation about the same as typical stars. A protoplanetary disk (or proplyd) is a rotating Circumstellar disk of dense gas surrounding a young newly formed star a T Tauri star or Herbig star [35]
2005, Gliese 876 d
In June, a third planet orbiting the red dwarf star Gliese 876 was announced. Gliese 876 d, also cataloged as IL Aquarii d, is an Extrasolar planet approximately 15 Light-years away in the Constellation of Aquarius According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool Star, of the Main sequence, either late K Gliese 876, also catalogued as IL Aquarii, is a Red dwarf Star approximately 15 Light-years away in the Constellation of With a mass estimated at 7. 5 times that of Earth, it is currently the second-lightest known exoplanet that orbits an ordinary main-sequence star. It may be rocky in composition. The planet orbits at 0. 021 AU with a period of 1. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the 94 days. [36]
2005, HD 149026 b
In July, a planet with the largest core known was announced. HD 149026 b is an Extrasolar planet approximately 257 Light-years away in the Constellation of Hercules. The planet, HD 149026 b, orbits the star HD 149026, and has a core that is estimated to be 70 Earth masses, accounting for two-thirds of the planet's mass. HD 149026 b is an Extrasolar planet approximately 257 Light-years away in the Constellation of Hercules. HD 149026 is a Yellow subgiant Star approximately 257 Light-years away in the Constellation of Hercules. [37]
Artist's impression of the planet OGLE-2005-BLG-390Lb (with surface temperature of approximately −220 °C), orbiting its star 20,000 light years (117.5 quadrillion miles) from Earth; this planet was discovered with gravitational microlensing.
Artist's impression of the planet OGLE-2005-BLG-390Lb (with surface temperature of approximately −220 °C), orbiting its star 20,000 light years (117. A light-year or light year (symbol ly) is a unit of Length, equal to just under ten trillion Kilometres As defined by 5 quadrillion miles) from Earth; this planet was discovered with gravitational microlensing. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001
2006, OGLE-2005-BLG-390Lb
On January 25, the discovery of OGLE-2005-BLG-390Lb was announced. Events 41 - After a night of negotiation Claudius is accepted as Roman Emperor by the Senate This is the most distant and probably the coldest exoplanet found to date. It is believed that it orbits a red dwarf star around 21,500 light years from Earth, towards the center of the Milky Way galaxy. The Milky Way (a translation of the Latin Via Lactea, in turn derived from the Greek Γαλαξίας (Galaxias sometimes referred to simply It was discovered using gravitational microlensing, and is estimated to have a mass of 5. 5 times that of Earth, making it the least massive known exoplanet to orbit an ordinary main-sequence star. Prior to this discovery, the few known exoplanets with comparably low masses had only been discovered on orbits very close to their parent stars, but this planet is estimated to have a relatively wide separation of 2. 6 AU from its parent star. [38][39]
2006, HD 69830
A planetary system with three Neptune-mass planets. HD 69830 is an Orange dwarf Star approximately 41 Light-years away in the Constellation of Puppis (the Poop Deck Neptune ( English|AmE] ] is the eighth and farthest Planet from the Sun in the Solar System. It is the first triple planetary system around a Sun-like star without any Jupiter-like planets. All three planets were announced on May 18 by Lovis. Events 1152 - Henry II of England marries Eleanor of Aquitaine. All three orbit within 1 AU. The planets b, c, d have masses of 10, 12, and 18 Earths respectively. HD 69830 b is a Neptune-mass or Super-Earth mass Extrasolar planet orbiting the star HD 69830. HD 69830 c is the 2nd Planet orbiting HD 69830. This is likely to be a Rocky planet, not a Gas giant. HD 69830 d is an Extrasolar planet Orbiting the Orange dwarf Star HD 69830 every 197 Days It is the outermost known The outermost planet d appears to be in the habitable zone, sheparding the asteroid belt. The asteroid belt is the region of the Solar System located roughly between the orbits of the Planets Mars and Jupiter. [40]
2007, HD 209458 b and HD 189733 b
On February 21, 2007, NASA and Nature released news that HD 209458 b and HD 189733 b were the first two extrasolar planets to have their spectra directly observed. HD 209458 b, also unofficially named Osiris, is an Extrasolar planet that orbits the Solar twin Star HD 209458 in the constellation HD 189733 b is an Extrasolar planet approximately 63 Light-years away in the Constellation of Vulpecula (the Fox) Events 362 - Athanasius returns to Alexandria. 1245 - Thomas, the first known Bishop of Finland Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program Nature is a prominent Scientific journal, first published on 4 November 1869 [41][42] This was long seen as the first mechanism by which extrasolar but non-intelligent life forms could be searched for, by way of influence on a planet's atmosphere. A group of investigators led by Dr. Jeremy Richardson of NASA's Goddard Space Flight Center were first to publication, in the February 22 issue of Nature. The Goddard Space Flight Center ( GSFC) is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight Richardson et al. spectrally measured HD 209458 b's atmosphere in the range of 7. 5 to 13. 2 micrometres. The results defied theoretical expectations in several ways. The spectrum had been predicted to have a peak at 10 micrometres which would have indicated water vapor in the atmosphere, but such a peak was absent, indicating no detectable water vapor. Another, unpredicted peak was observed at 9. 65 micrometres, which the investigators attributed to clouds of silicate dust, a phenomenon not previously observed. Another unpredicted peak occurred at 7. 78 micrometres, which the investigators did not have an explanation for. A separate team led by Mark Swain of the Jet Propulsion Laboratory also separately analyzed the Richardson team's data and indicated that their findings were similar. They had submitted their results to Astrophysical Journal Letters. The Astrophysical Journal (abbreviated to ApJ or Astrophys J) is a Scientific journal covering Astronomy and Astrophysics. A team led by Carl Grillmair of NASA's Spitzer Science Center made the observations of HD 189733 b, and their results were pending publication in Astrophysical Journal Letters at the time of the news release. The California Institute of Technology (commonly referred to as Caltech) is a private, Coeducational research university located in Pasadena On July 11, 2007, the findings by the Spitzer Science Center were published in the Nature: Spectral imprints of water vapor were found by the Spitzer Space Telescope, thus representing the first solid evidence of water on an extrasolar planet. Events 911 - Signing of the Treaty of Saint-Clair-sur-Epte between Charles the Simple and Rollo of Normandy. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. The Spitzer Space Telescope (formerly the Space Infrared Telescope Facility, SIRTF) is an Infrared Space observatory. [43]
Artist's Impression of Gliese 581 c
Artist's Impression of Gliese 581 c
2007, Gliese 581 c
Announced on Space.com on April 24, 2007, at 4:23pm ET, it has been determined that this exoplanet could support liquid water and possibly life. Gliese 581 c (ˈgliːzə is a " Super-earth " Gliese 581 c (ˈgliːzə is a " Super-earth " Spacecom is a Space and Astronomy news website Its stories are often syndicated to other media outlets including CNN, MSNBC Events 1479 BC - Thutmose III ascends to the throne of Egypt, although power effectively shifts to Hatshepsut (according to Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. [44] While evidence of liquid water has not been detected, the position of this planet—being in a position that might be within the host star's habitable zone—would allow for water to exist in its liquid state. In Astronomy a habitable zone ( HZ) is a region of space where conditions are favorable for Life as it may be found on Earth. Seth Shostak, a senior astronomer with the SETI institute, stated that on two previous occasions, Gliese 581 was looked at as a potential candidate for extraterrestrial intelligence, but both examinations revealed no proof. Seth Shostak is an American Astronomer. He earned his Physics degree from Princeton University and a Ph Extraterrestrial life is Life originating outside of the Earth. The confirmation of the exoplanet's position was determined using the HARPS instrument on the European Southern Observatory's 3. Spectrograph is in a state of flux do not create Echelle spectrograph until we know where to redirect to probably Spectrography#Echelle spectrograph -->The 6 meter telescope, by applying the radial velocity detection method. Any Planet is an extremely faint light source compared to its parent Star. Gliese 581 c is estimated to be fifty percent larger than Earth and close to five times Earth's mass. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 Some researchers argue that Gliese 581 c will have a runaway greenhouse effect, and thus would not be habitable. [45] They argue, however, that Gliese 581 d is near the outer edge of the Habitable zone. Gliese 581 d (ˈgliːzə is an Extrasolar planet approximately 20 Light-years away in the Constellation of Libra.
2007, Gliese 436 b 
This planet was one of the first Neptune-mass planet discovered in August 2004. Gliese 436 b (ˈgliːzə ( GJ 436 b) is a Neptune -sized Extrasolar planet orbiting the red dwarf star Gliese 436. Neptune ( English|AmE] ] is the eighth and farthest Planet from the Sun in the Solar System. In May 2007, a transit was found, which make it the least massive transiting planet as of yet. Spectral studies found that this planet contains exotic form of solid water called "hot ice," which exists, despite the planet's high temperatures, because the planet's gravity causes water to be extremely dense. Data indicates that it is a rocky and watery planet with a mass 22 times that of Earth. [46]
2007, XO-3b 
A 13. 24 Jupiter-mass planet is the most massive transiting planet ever found, and most massive extrasolar planet found to date, just above the brown dwarf limit at 13. Brown dwarfs are sub- stellar objects with a mass below that necessary to maintain Hydrogen -burning Nuclear fusion reactions in their cores as do stars 00 MJ. The planet would have radius of 1. 92 times Jupiter, the largest of any known extrasolar planets. The planet takes only 3. 19 days to orbit the star. The orbit has an unusually high eccentricity (0. 22) for such a short period planet. [47]
2007, TrES-4 
The largest-diameter and lowest-density exoplanet to date, TrES-4 is 1. TrES-4 is an Exoplanet discovered in 2006 TrES-4 orbits its primary Star every 3 7 times Jupiter's diameter but only 0. 84 times its mass, giving it a density of just 0. 2 grams per cubic centimeter — about the same as balsa wood. It orbits its primary closely and is therefore quite hot, but stellar heating alone does not appear to explain its large size. [48]
2008, OGLE-2006-BLG-109Lb and OGLE-2006-BLG-109Lc
On February 14 the discovery of the, until now, most similar Jupiter-Saturn planetary system constellation was announced, with the ratios of mass, distance to their star and orbiting time similar to that of Jupiter-Saturn. Events 842 - Charles the Bald and Louis the German swear the Oaths of Strasbourg in the French and German This can be important for possible life in a solar system as Jupiter and Saturn have a stabilizing effect to the habitable zone by sweeping away large asteroids from the habitable zone. Life is a state that distinguishes Organisms from non-living objects such as non-life and dead organisms being manifested by growth through Metabolism The Solar System consists of the Sun and those celestial objects bound to it by Gravity. In Astronomy a habitable zone ( HZ) is a region of space where conditions are favorable for Life as it may be found on Earth. Asteroids, sometimes called Minor planets or planetoids', are bodies—primarily of the inner Solar System —that are smaller than planets but [49]
2008, HD 189733 b
On March 20 follow up studies to the first spectral analyses of an extrasolar planet were published in the scientific journal Nature, announcing evidence of an organic molecule found on an extrasolar planet for the first time. HD 189733 b is an Extrasolar planet approximately 63 Light-years away in the Constellation of Vulpecula (the Fox) Events 1600 - The Linköping Bloodbath takes place on Maundy Thursday in Linköping, Sweden. Nature is a prominent Scientific journal, first published on 4 November 1869 In 2007 water vapor was already detected in the spectrum of HD 189733 b, but new analyses showed not only water vapor, but also methane existing in the atmosphere of the giant gas planet. HD 189733 b is an Extrasolar planet approximately 63 Light-years away in the Constellation of Vulpecula (the Fox) Although conditions on HD 189733 b are too harsh to harbor life, it still is the first time a key molecule for organic life was found on an extrasolar planet. [50]
2008, announcement of 45 new planet candidates
On May 20, Christophe Lovis of the HARPS team at an international meeting in Boston, Massachusetts announced 45 new planets orbiting around nearby stars, all with masses less than one-tenth Jupiter mass. Events 325 - The First Council of Nicaea &ndash the first Ecumenical Council of the Christian Church is held The Commonwealth of Massachusetts ( is a state located in the New England region of the northeastern United States. Jupiter mass is the unit of Mass equal to one Jupiter (18986 × 1027 kg, 317 These were detected by the gravitational tug method using the HARPS located in La Silla, Chile. Doppler spectroscopy, also known as Radial velocity measurement is a spectroscopic method for finding Extrasolar planets It involves the observation Spectrograph is in a state of flux do not create Echelle spectrograph until we know where to redirect to probably Spectrography#Echelle spectrograph -->The La Silla Observatory is an astronomical observatory in Chile with eighteen telescopes Chile, officially the Republic of Chile ( Spanish:) is a country in South America occupying a long and narrow Coastal strip wedged between the The discoveries represented a significant increase in the numbers of known super-earths. A Super-Earth is an extrasolar Terrestrial planet more massive than the Earth Astronomers suggest that such low-mass planets may outnumber the Jupiter-like planets by 3 to 1. [51] While the announcement is not yet official (more data are needed to confirm the candidates), some news media picked up the story.


Discovery firsts

Title Planet Star Year Notes
First planet discovered PSR B1257+12 B, C PSR B1257+12 1992 first extrasolar planets discovered
Note 1: The planet around Gamma Cephei was already suspected in 1988. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. Gamma Cephei (γ Cep / γ Cephei traditionally named Errai, Er Rai, and or Alrai, is a binary star system approximately 45 Light-years
Note 2: HD 114762 b was discovered in 1989, but was not confirmed as a planet before 1996. HD 114762 is a yellow-white Main sequence Star approximately 132 Light years away in the Constellation Coma Berenices.
First discovery by a method
First planet discovered using the pulsar timing method PSR B1257+12 B, C PSR B1257+12 1992
First planet discovered by radial velocity method 51 Pegasi b 51 Pegasi 1995
First planet discovered by transit method OGLE-TR-56 b OGLE-TR-56 2002
NOTE: The first discovered transiting planet was HD 209458 b, which had already been discovered. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. Radial velocity is the Velocity of an object in the direction of the line of sight (i 51 Pegasi b, also unofficially named Bellerophon and or abbreviated as 51 Peg b, is an Extrasolar planet approximately 50 Light-years 51 Pegasi is a Sun -like star (although somewhat older than the Sun located 15 The term transit or astronomical transit has three meanings in astronomy A transit is the astronomical event that occurs when one OGLE-TR-56 is a Sun -like Star | period = 1211909 ± 0000001| eccentricity = 0}} See also List of stars with confirmed extrasolar OGLE-TR-56 is a Sun -like Star | period = 1211909 ± 0000001| eccentricity = 0}} See also List of stars with confirmed extrasolar HD 209458 b, also unofficially named Osiris, is an Extrasolar planet that orbits the Solar twin Star HD 209458 in the constellation
First planet found by gravitational lensing method OGLE-2003-BLG-235Lb OGLE-2003-BLG-235L/MOA-2003-BLG-53L 2004
First discovery by system type
First planet around a solitary star PSR B1257+12 B, C PSR B1257+12 1992 first extrasolar planets discovered
Note 1: HD 114762 b was discovered in 1989, but was not confirmed as a planet before 1996. A gravitational lens is formed when the light from a very distant bright source (such as a Quasar) is "bent" around a massive object (such as a cluster of OGLE-2003-BLG-235/MOA 2003-BLG-53 was a Gravitational microlensing event which occurred in the Constellation of Sagittarius during July 2003 OGLE-2003-BLG-235/MOA 2003-BLG-53 was a Gravitational microlensing event which occurred in the Constellation of Sagittarius during July 2003 PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. HD 114762 is a yellow-white Main sequence Star approximately 132 Light years away in the Constellation Coma Berenices.
First free-floating planet discovered S Ori 70 n/a 2004 has mass of 3 MJupiter, needs confirmation
Note: Free-floating objects are not usually considered planets.
First planet in a multiple star system discovered 55 Cancri b 55 Cancri 1996 55 Cnc has distant red dwarf companion
Note 1: The planet around Gamma Cephei was already suspected in 1988. 55 Cancri (ˈkæŋkraɪ or /ˈkæŋkriː/ also catalogued Rho1 Cancri or abbreviated 55 Cnc, is a Binary star approximately 41 Light-years 55 Cancri (ˈkæŋkraɪ or /ˈkæŋkriː/ also catalogued Rho1 Cancri or abbreviated 55 Cnc, is a Binary star approximately 41 Light-years Gamma Cephei (γ Cep / γ Cephei traditionally named Errai, Er Rai, and or Alrai, is a binary star system approximately 45 Light-years
Note 2: Gamma Cephei is the first relatively close binary with a planet. Gamma Cephei (γ Cep / γ Cephei traditionally named Errai, Er Rai, and or Alrai, is a binary star system approximately 45 Light-years
First planet orbiting multiple stars discovered PSR B1620-26c PSR B1620-26 1993 orbits pulsar - white dwarf pair
First multiple planet system discovered PSR 1257+12 A, B, C PSR 1257+12 1992 a pulsar planetary system
First planet in star cluster PSR B1620-26c PSR B1620-26 1993 located in Globular Cluster M4
First discovery by star type
First pulsar planet discovered PSR B1257+12 B, C PSR B1257+12 1992
First known planet orbiting a Sun-like star 51 Pegasi b 51 Pegasi 1995
First known planet orbiting a red dwarf Gliese 876 b Gliese 876 1998
First known planet orbiting a giant star Iota Draconis b Iota Draconis 2002
First known planet orbiting a white dwarf (confirmed 2003) PSR B1620-26c PSR B1620-26 1993 in December 2007, GD 66 b was discovered orbiting a solitary white dwarf star GD 66
First known planet orbiting a brown dwarf 2M1207b 2M1207 2004 first directly imaged planet
First free-floating planet discovered S Ori 70 n/a 2004 has mass of 3 MJupiter, needs confirmation
Note: Free-floating objects are not usually considered planets. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves Pulsar planets are Planets that are found orbiting Pulsars or rapidly rotating Neutron stars The first such planet to be discovered was Messier 4 (also known as M4 or NGC 6121) is a Globular cluster in the Constellation Scorpius. Pulsar planets are Planets that are found orbiting Pulsars or rapidly rotating Neutron stars The first such planet to be discovered was PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. The main sequence is the name for a continuous and distinctive band of stars that appear on a plot of stellar color versus brightness 51 Pegasi b, also unofficially named Bellerophon and or abbreviated as 51 Peg b, is an Extrasolar planet approximately 50 Light-years 51 Pegasi is a Sun -like star (although somewhat older than the Sun located 15 According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool Star, of the Main sequence, either late K Gliese 876, also catalogued as IL Aquarii, is a Red dwarf Star approximately 15 Light-years away in the Constellation of Gliese 876, also catalogued as IL Aquarii, is a Red dwarf Star approximately 15 Light-years away in the Constellation of A giant star is a Star with substantially larger Radius and Luminosity than a Main sequence star of the same surface temperature. Iota Draconis b was discovered in 2001 during a Radial velocity study of K-class giant stars and was the first planet discovered orbiting a Giant star Iota Draconis (ι Dra / ι Draconis is an orange giant Star located away in the Constellation Draco. A white dwarf, also called a degenerate dwarf, is a small Star composed mostly of Electron-degenerate matter. PSR B1620-26 is a Binary star system approximately 12400 Light-years away in the Constellation of Scorpius. GD 66 or V361 Aurigae is a 064 solar mass White dwarf star located 166 Light years from Earth in Auriga constellation GD 66 or V361 Aurigae is a 064 solar mass White dwarf star located 166 Light years from Earth in Auriga constellation Brown dwarfs are sub- stellar objects with a mass below that necessary to maintain Hydrogen -burning Nuclear fusion reactions in their cores as do stars 2M1207b is a Planetary mass object orbiting the Brown dwarf 2M1207, in the constellation Centaurus, approximately 170 Light-years 2M1207, 2M1207A or 2MASSW J1207334−393254 is a Brown dwarf located in the Constellation Centaurus; a companion object 2M1207b
Firsts by planet type
first cool, possibly rocky/icy planet around main-sequence star OGLE-2005-BLG-390Lb OGLE-2005-BLG-390L 2006
Other firsts
First transiting planet HD 209458 b HD 209458 1999
Note: OGLE-TR-56 b is the first planet found by transit method. OGLE-2005-BLG-390L is a star thought to be a Spectral type M - Red dwarf star (95% probability 4% probability it is a White dwarf, The term transit or astronomical transit has three meanings in astronomy A transit is the astronomical event that occurs when one HD 209458 b, also unofficially named Osiris, is an Extrasolar planet that orbits the Solar twin Star HD 209458 in the constellation HD 209458 is an 8th magnitude Star in the Constellation Pegasus.
First directly imaged planet 2M1207b 2M1207 2004 first planet found around brown dwarf

See also

Classification

System

Observatories

Missions

Astronomers

Books

Lists

Habitability

References

  1. ^ a b c Schneider, Jean (2007-04-25). Aleksander Wolszczan (alɛk'sandɛr 'vɔlʂt͡ʂan) ( Apr 29 1946 in Szczecinek, Poland) is a Polish astronomer. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. Dale A Frail is a Canadian radio Astronomer working for the National Radio Astronomy Observatory (NRAO in Socorro New Mexico. PSR B1257+12, sometimes abbreviated as PSR 1257+12, is a Pulsar located 980 Light-years from the Sun. Michel G E Mayor (born 12 January, 1942) is a Swiss professor in the Department of Astronomy at the University of Geneva. 51 Pegasi b, also unofficially named Bellerophon and or abbreviated as 51 Peg b, is an Extrasolar planet approximately 50 Light-years Didier Queloz (born February 23 1966) is a Geneva -based Astronomer with a prolific record in finding Extrasolar planets He is understudy 51 Pegasi b, also unofficially named Bellerophon and or abbreviated as 51 Peg b, is an Extrasolar planet approximately 50 Light-years Stéphane Udry (born 1961 in Sion Switzerland) is an astronomer at the University of Geneva in Switzerland, whose current work is primarily Gliese 581 c (ˈgliːzə is a " Super-earth " Distant Wanderers The Search for Planets Beyond the Solar System is a book written by science journalist Bruce Dorminey, which reports on astronomical research and The following are lists of stars with confirmed Extrasolar planets. The following are lists of extremes among the known Extrasolar planets The properties listed here are those for which values are reliably known for the majority of the known sample of extrasolar This is a list of unconfirmed Extrasolar planets When a planet candidate is confirmed please remove it from this list and move it to List of stars with confirmed extrasolar planets Planetary habitability is the measure of a Planet 's or a Natural satellite 's potential to develop and sustain Life. Extraterrestrial life is Life originating outside of the Earth. Extraterrestrial liquid water, the presence of Water in its Liquid state is a subject of wide interest because it is a commonly suggested prerequisite for the emergence Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1607 - Eighty Years' War: The Dutch fleet destroys the anchored Spanish fleet at Gibraltar. Interactive Extra-solar Planets Catalog. The Extrasolar Planets Encyclopedia. Retrieved on 2008-05-31. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1279 BC - Rameses II (The Great (19th dynasty becomes pharaoh of Ancient Egypt.
  2. ^ "Rock planets outnumber gas giants", msn, 2008-05-28. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 585 BC - A Solar eclipse occurs as predicted by Greek philosopher and scientist Thales, while Alyattes is battling Retrieved on 2008-05-28. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 585 BC - A Solar eclipse occurs as predicted by Greek philosopher and scientist Thales, while Alyattes is battling  
  3. ^ a b c d Marcy, G. ; Butler, R. ; Fischer, D. ; et. al. (2005). "Observed Properties of Exoplanets: Masses, Orbits and Metallicities". Progress of Theoretical Physics Supplement 158: 24 – 42.  
  4. ^ Terrestrial Planet Finder science goals: Detecting signs of life. JPL Terrestrial Planet Finder website. Retrieved on 2006-07-21. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 356 BC - Herostratus sets fire to the Temple of Artemis in Ephesus, one of the Seven Wonders of the World
  5. ^ Jacob, W. S. (1855). "On Certain Anomalies presented by the Binary Star 70 Ophiuchi". Monthly Notices of the Royal Astronomical Society 15: 228.  
  6. ^ See, Thomas Jefferson Jackson (1896). Thomas Jefferson Jackson (T J J See, (1866 to July 4 1962 was an American Astronomer (born near Montgomery City, Missouri) who received "Researches on the Orbit of F. 70 Ophiuchi, and on a Periodic Perturbation in the Motion of the System Arising from the Action of an Unseen Body". The Astronomical Journal 16: 17.  
  7. ^ Sherrill, Thomas J. (1999). "A Career of controversy: the anomaly OF T. J. J. See". Journal for the history of astronomy 30.  
  8. ^ van de Kamp, Peter (August 1969). Piet Van de Kamp (December 26 1901 Kampen &ndash May 18 1995 known as Peter van de Kamp in the United States, was a Dutch Astronomer "Alternate dynamical analysis of Barnard's star". The Astronomical Journal 74: 757-759.  
  9. ^ Bailes, M. ; Lyne, A. G. ; Shemar, S. L. (1991). "A planet orbiting the neutron star PSR1829-10". A neutron star is a type of remnant that can result from the Gravitational collapse of a massive Star during a Type II, Type Ib or Type Nature 352: 311 – 313.  
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  11. ^ Campbell, B. ; Walker, G. A. H. ; Yang, S. (1988). "A search for substellar companions to solar-type stars". Astrophysical Journal, Part 1 331: 902 – 921.  
  12. ^ Lawton, A. T. ; Wright, P. (1989). "A planetary system for Gamma Cephei?". British Interplanetary Society, Journal 42: 335 – 336.  
  13. ^ Walker, G. A. H. ; Bohlender, D. A. ; Walker, A. R. ; Irwin, A. W. ; Yang, S. L. S. ; Larson, A. (1992). "Gamma Cephei - Rotation or planetary companion?". Astrophysical Journal, Part 2 - Letters 396 (2): L91 – L94.  
  14. ^ Hatzes et al. (2003). "A Planetary Companion to Gamma Cephei A". The Astrophysical Journal 599 (2): 1383 – 1394. The Astrophysical Journal (abbreviated to ApJ or Astrophys J) is a Scientific journal covering Astronomy and Astrophysics.  
  15. ^ a b Wolszczan, A. ; Frail, D. A. (1992). "A planetary system around the millisecond pulsar PSR1257+12". Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves Nature 355: 145 – 147.  
  16. ^ a b Mayor, Michel; Queloz, Didier (1995). "A Jupiter-mass companion to a solar-type star". Nature 378: 355 – 359.  
  17. ^ An especially simple and inexpensive method for measuring radial velocity is “externally dispersed interferometry. ” See the following Web site: http://www.spectralfringe.org/EDI/ . See also: Erskine, Edelstein, Harbeck and Lloyd, “Externally dispersed interferometry for planetary studies,” in Techniques and Instrumentation for Detection of Exoplanets II, Daniel R. Coulter, ed. , Proceedings of the SPIE *, vol. 5905, pages 249-260 (2005). Available on-line at: https://e-reports-ext.llnl.gov/pdf/322047.PDF . (* SPIE = Society of Photo-optical Instrumentation Engineers; renamed: International Society for Optical Engineering)
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  19. ^ http://www.iau.org/PLANETS_AROUND_OTHER_STARS.247.0.html Planets Around Other Stars. Retrieved on 12/8/06.
  20. ^ Working Group on Extrasolar Planets: Definition of a "Planet". IAU position statement (February 28, 2003). Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule Year 2003 ( MMIII) was a Common year starting on Wednesday of the Gregorian calendar. Retrieved on 2006-09-09. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1000 - Battle of Svolder, Viking Age. 1379 - Treaty of Neuberg, splitting the Austrian
  21. ^ Why Planets Will Never Be Defined (2006). Retrieved on 2008-02-13. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1258 - Baghdad falls to the Mongols, and the Abbasid Caliphate is destroyed
  22. ^ Bonfils, X. ; Forveille, T. ; Delfosse, X. ; et. al. (2005). "The HARPS search for southern extra-solar planets VI: A Neptune-mass planet around the nearby M dwarf Gl 581". Astronomy & Astrophysics 443: L15 – L18. doi:10.1051/0004-6361:200500193. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  23. ^ Linda Vu (October 3, 2006). Planets Prefer Safe Neighborhoods. Retrieved on 2007-09-01. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 462 - Possible start of first Byzantine indiction cycle.
  24. ^ Charbonneau, D. ; T. Brown; A. Burrows; G. Laughlin (2006). "When Extrasolar Planets Transit Their Parent Stars". Protostars and Planets V, University of Arizona Press.  
  25. ^ Scientists Snap Images of First Brown Dwarf in Planetary System (News Release). Eberley CoS website (September 18, 2006). Retrieved on 2006-09-28. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 48 BC - Pompey the Great is assassinated on orders of King Ptolemy of Egypt after landing in Egypt.
  26. ^ "UC Berkeley astronomers find Jupiter-sized planet around nearby star in Big Dipper". Retrieved on 2007-08-26. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1071 - Battle of Manzikert: The Seljuk Turks defeat the Byzantine Army at Manzikert.  
  27. ^ John Nobile Wilford (2001). "New Planet Detected Around a Star 15 Light Years Away". The New York Times.  
  28. ^ Blake Edgar, Megan Watzke, Carol Rasmussen (1999). "Multiple planets discovered around Upsilon Andromedae". Extrasolar planets 415, 617, 303: 338 – 6747, 495 – 7463, 497 – 8611.  
  29. ^ Henry et al. (2000). "A Transiting "51 Peg-like" Planet". The Astrophysical Journal Letters 529 (1): L41 – L44.  
  30. ^ Charbonneau et al. (2002). "Detection of an Extrasolar Planet Atmosphere". The Astrophysical Journal 568 (1): 377 – 384. The Astrophysical Journal (abbreviated to ApJ or Astrophys J) is a Scientific journal covering Astronomy and Astrophysics.  
  31. ^ Frink et al. (2002). "Discovery of a Substellar Companion to the K2 III Giant Iota Draconis". The Astrophysical Journal 576 (1): 478 – 484. The Astrophysical Journal (abbreviated to ApJ or Astrophys J) is a Scientific journal covering Astronomy and Astrophysics.  
  32. ^ Sigurdsson, S. ; Richer, H. B. ; Hansen, B. M. ; Stairs I. H. ; Thorsett, S. E. (2003). "A Young White Dwarf Companion to Pulsar B1620-26: Evidence for Early Planet Formation". Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves Science 301 (5630): 193 – 196.  
  33. ^ Fourteen Times the Earth - ESO HARPS Instrument Discovers Smallest Ever Extra-Solar Planet. ESO website. Retrieved on 2006-05-07. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 558 - In Constantinople, the dome of the Hagia Sophia collapses
  34. ^ Konacki, M. (2005). "Astronomers Confirm the First Image of a Planet Outside of Our Solar System". ESO.  
  35. ^ R. Jayawardhana, N. Huelamo, E. Mamajek (2006). "The Planetary Mass Companion 2MASS1207-3932 B: Temperature, Mass and Evidence for an Edge-On Disk". American Astronomical Society.  }
  36. ^ Rivera et al. (2005). "A 7.5 Me Planet Orbiting the Nearby Star GJ 876". The Astrophysical Journal 634 (1): 625 – 640. The Astrophysical Journal (abbreviated to ApJ or Astrophys J) is a Scientific journal covering Astronomy and Astrophysics.  
  37. ^ Sato, B. ; Fischer, D. ; Henry, G. ; Laughlin, G. ; Butler, R. ; Marcy, G. ; Vogt, S. ; Bodenheimer, P. ; Ida, S. ; Toyota, E. ; Wolf, A. ; Valenti, J. ; Boyd, L. ; Johnson, J. ; Wright, J. ; Ammons, M. ; Robinson, S. ; Strader, J. ; McCarthy, C. ; Tah, K. ; Minniti, D. (2005). "The N2K Consortium II: A Transiting Hot Saturn around HD 149026 with a Large Dense Core". The Astrophysical Journal 633: 465 – 473.  
  38. ^ J. -P. Beaulieu; D. P. Bennett; P. Fouque; A. Williams; M. Dominik; U. G. Jorgensen; D. Kubas; A. Cassan; C. Coutures; J. Greenhill; K. Hill; J. Menzies; P. D. Sackett; M. Albrow; S. Brillant; J. A. R. Caldwell; J. J. Calitz; K. H. Cook; E. Corrales; M. Desort; S. Dieters; D. Dominis; J. Donatowicz; M. Hoffman; S. Kane; J. -B. Marquette; R. Martin; P. Meintjes; K. Pollard; K. Sahu; C. Vinter; J. Wambsganss; K. Woller; K. Horne; I. Steele; D. Bramich; M. Burgdorf; C. Snodgrass; M. Bode; A. Udalski; M. Szymanski; M. Kubiak; T. Wieckowski; G. Pietrzynski; I. Soszynski; O. Szewczyk; L. Wyrzykowski; B. Paczynski (2006). "Discovery of a Cool Planet of 5.5 Earth Masses Through Gravitational Microlensing". Nature 439: 437 – 440.  
  39. ^ Kiwis help discover new planet. One News (Jan 26, 2006). Retrieved on 2006-05-07. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 558 - In Constantinople, the dome of the Hagia Sophia collapses
  40. ^ Trio of Neptunes and their belt (May 18, 2006). Retrieved on 2007-06-09. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 53 - Roman Emperor Nero marries Claudia Octavia 62 - Claudia Octavia commits
  41. ^ http://www.spitzer.caltech.edu/Media/releases/ssc2007-04/release.shtml Spitzer. caltech. edu Retrieved on 04-25-07
  42. ^ http://www.nature.com/nature/journal/v445/n7130/abs/nature05636.html Nature. com Retrieved on 04-25-07
  43. ^ 'Clear Signs of Water' on Distant Planet at Space.com
  44. ^ Ker Than (Apr 24, 2007 4:23pm ET). Spacecom is a Space and Astronomy news website Its stories are often syndicated to other media outlets including CNN, MSNBC Major Discovery: New Planet Could Harbor Water and Life. Retrieved on 2007-04-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1479 BC - Thutmose III ascends to the throne of Egypt, although power effectively shifts to Hatshepsut (according to
  45. ^ The Habitability of Super-Earths in Gliese 581. Retrieved on 2007-05-29. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 363 - Roman Emperor Julian defeats the Sassanid army in the Battle of Ctesiphon, under the walls of the
  46. ^ Fox, Maggie. "Hot "ice" may cover recently discovered planet", 16 May 2007. Retrieved on 2007-12-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1065 - Westminster Abbey is Consecrated. 1308 - The reign of Emperor Hanazono, Emperor of  
  47. ^ Krull et al. (2007-05-30). "XO-3b: A Massive Planet in an Eccentric Orbit Transiting an F5V Star".  
  48. ^ "Largest Known Exoplanet Discovered", SPACE. com, Aug 6, 2007. Retrieved on 2007-08-26. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1071 - Battle of Manzikert: The Seljuk Turks defeat the Byzantine Army at Manzikert.  
  49. ^ "Solar System Like Ours Found", SPACE. com, February 14, 2008. Retrieved on 2008-02-19. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 197 - Roman Emperor Septimius Severus defeats usurper Clodius Albinus in the Battle of Lugdunum  
  50. ^ "Key Organic Molecule Detected at Extrasolar Planet", SPACE. com, March 20, 2008. Retrieved on 2008-03-20. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1600 - The Linköping Bloodbath takes place on Maundy Thursday in Linköping, Sweden.  
  51. ^ "Rock planets outnumber gas giants", msn, 2008-05-28. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 585 BC - A Solar eclipse occurs as predicted by Greek philosopher and scientist Thales, while Alyattes is battling Retrieved on 2008-05-28. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 585 BC - A Solar eclipse occurs as predicted by Greek philosopher and scientist Thales, while Alyattes is battling  

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extrasolar planet

-noun

  1. Alternative form of exoplanet..
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