2M1207, 2M1207A or 2MASSW J1207334-393254 is a brown dwarf star located in the constellation Hydra; a companion object, 2M1207b, is believed to be one of the first extrasolar planets to be directly imaged, and is the first exoplanet to be discovered in orbit of a brown dwarf. From the Glossary of Astronomical Terms by the Harvard-Smithsonian Center for Astrophysics: Either of the two points (vernal, autumnal) on the celestial sphere where the ecliptic (which is the apparent path of the sun on the sky) intersects the celestial equator. ... It has been suggested that this article or section be merged into Julian epoch. ... This article or section does not cite its references or sources. ... Hydra (IPA: ) is the largest of the 88 modern constellations, and was also one of the 48 constellations listed by Ptolemy. ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... // Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ... This article is in need of attention from an expert on the subject. ... A light-year or lightyear, symbol ly, is a unit of length. ... Stellar parallax motion The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... In astronomy, many stars are referred to simply by catalogue numbers. ... This brown dwarf (smaller object) orbits the star Gliese 229, which is located in the constellation Lepus about 19 light years from Earth. ... This article is about the astronomical object. ... This article or section does not cite its references or sources. ... Hydra (IPA: ) is the largest of the 88 modern constellations, and was also one of the 48 constellations listed by Ptolemy. ... 2M1207b is an extrasolar planet orbiting the brown dwarf 2M1207, a star in the constellation Hydra approximately 200 light years from Earth. ... Infrared Image of a possible extrasolar planet (lower left) in the Constellation Taurus, taken by the Hubble Space Telescope. ...

Located at right ascension 12hr 7min 33.4sec, and declination -39° 32′ 54″ (J2000.0 celestial coordinates), 2M1207 was discovered during the course of the 2MASS infrared sky survey: hence the "2M" in its name, followed by its celestial coordinates. It is roughly 53 parsecs away; with a fairly early (for a brown dwarf) spectral type of M8, it is very young, and a likely member of the TW Hydrae association. Its estimated mass is around 21 Jupiter masses. Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... It has been suggested that this article or section be merged into Julian epoch. ... In astronomy, a celestial coordinate system is a coordinate system for mapping positions in the sky. ... Observations for the Two Micron All-Sky Survey (2MASS) began in 1997 and were completed in 2001 at two telescopes located one each in the northern and southern hemispheres (Mt. ... ... Stellar parallax motion The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... TW Hydrae is the nearest classical T Tauri star to the Sun, situated some 56 parsecs away in the constellation in Hydra. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ...

In December 2005, American astronomer Eric Mamajek reported a more accurate distance to 2M1207 using the moving cluster method. The new distance (revised downwards from 70 parsecs) results in a fainter luminosity for 2M1207A, and its mass was revised downwards from an original value of 25 Jupiter masses.
Luminosity has different meanings in several different fields of science. ...

2M1207b

Main article: 2M1207b

European Southern Observatory infrared image of 2M1207 (blueish) and companion planet 2M1207b (reddish), taken in 2004.

2M1207b is a planetary mass companion to 2M1207 detected in 2004 by imaging. It is approximately 5.1125694 × 10^9 miles away from its star, 2M1207.
2M1207b is an extrasolar planet orbiting the brown dwarf 2M1207, a star in the constellation Hydra approximately 200 light years from Earth. ... An extrasolar planet, or exoplanet, is a planet beyond the Solar System. ... The following are lists of stars with confirmed extrasolar planets. ... The astronomical unit (AU or au or a. ... Unsolved problems in physics: What causes anything to have mass? Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... Adjectives: Jovian Atmosphere Surface pressure: 70 kPa Composition: ~86% Hydrogen ~14% Helium 0. ... Remote Authentication Dial In User Service (RADIUS) is an AAA (authentication, authorization and accounting) protocol for applications such as network access or IP mobility. ... Adjectives: Jovian Atmosphere Surface pressure: 70 kPa Composition: ~86% Hydrogen ~14% Helium 0. ... Density, or volumic mass (ISO 31), is a measure of mass per volume. ... The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. It was assigned to the United States in 1889 and is periodically recertified and traceable to the primary international standard, The Kilogram, held at the Bureau International des Poids et... The cubic meter (symbol m³) is the SI derived unit of volume. ... Fig. ... The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ... 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... Any planet is an extremely faint light source compared to its parent star. ... Image File history File links Phot-14a-05-preview. ... Image File history File links Phot-14a-05-preview. ... The European Southern Observatory (ESO) is an international astronomical organisation, composed and supported by ten countries from the European Union plus Switzerland. ... 2M1207b is an extrasolar planet orbiting the brown dwarf 2M1207, a star in the constellation Hydra approximately 200 light years from Earth. ...

References

• Space.com - Astronomers Confident: Planet Beyond Solar System Has Been Photographed
• Space.com article on the discovery
• Extrasolar Planets Encyclopedia page on 2M1207 b
• "A Giant Planet Candidate Near a Young Brown Dwarf" (PDF) from the European Southern Observatory.
• "A Moving Cluster Distance to the Exoplanet 2M1207b in the TW Hydrae Association"