Английская Википедия:2M1207
Шаблон:Short description Шаблон:Starbox begin Шаблон:Starbox image Шаблон:Starbox observe Шаблон:Starbox character Шаблон:Starbox astrometry Шаблон:Starbox detail Шаблон:Starbox catalog Шаблон:Starbox reference Шаблон:Starbox end 2M1207, 2M1207A or 2MASS J12073346–3932539 is a brown dwarf located in the constellation Centaurus; a companion object, 2M1207b, may be the first extrasolar planetary-mass companion to be directly imaged, and is the first discovered orbiting a brown dwarf.[1][2]
2M1207 was discovered during the course of the 2MASS infrared sky survey: hence the "2M" in its name, followed by its celestial coordinates. With a fairly early (for a brown dwarf) spectral type of M8,[3] it is very young, and probably a member of the TW Hydrae association. Its estimated mass is around 25 Jupiter masses.[4] The companion, 2M1207b, is estimated to have a mass of 5–6 Jupiter masses.[5] Still glowing red hot, it will shrink to a size slightly smaller than Jupiter as it cools over the next few billion years.
An initial photometric estimate for the distance to 2M1207 was 70 parsecs.[4] In December 2005, American astronomer Шаблон:Interlanguage link multi reported a more accurate distance (53 ± 6 parsecs) to 2M1207 using the moving cluster method.[6] The new distance gives a fainter luminosity for 2M1207. Recent trigonometric parallax results have confirmed this moving cluster distance, leading to a distance estimate of 53 ± 1 parsec or 172 ± 3 light years.[4]
Planetary system
Like classical T Tauri stars, many brown dwarfs are surrounded by disks of gas and dust which accrete onto the brown dwarf.[7][8] 2M1207 was first suspected to have such a disk because of its broad Hα line. This was later confirmed by ultraviolet spectroscopy.[8] The existence of a dust disk has also been confirmed by infrared observations[9] and with ALMA.[10] In general, accretion from disks are known to produce fast-moving jets, perpendicular to the disk, of ejected material.[11] This has also been observed for 2M1207; an April 2007 paper in the Astrophysical Journal reports that this brown dwarf is spouting jets of material from its poles.[12] The jets, which extend around 109 kilometers into space, were discovered using the Very Large Telescope (VLT) at the European Southern Observatory. Material in the jets streams into space at a few kilometers per second.[13]
Шаблон:OrbitboxPlanet begin Шаблон:OrbitboxPlanet disk Шаблон:OrbitboxPlanet Шаблон:Orbitbox end
See also
References
External links
- Space.com - Astronomers Confident: Planet Beyond Solar System Has Been Photographed
- Space.com article on the discovery
- Шаблон:Cite web
- "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"
- ↑ Ошибка цитирования Неверный тег
<ref>; для сносокmohantyне указан текст - ↑ Шаблон:Cite journal
- ↑ Ошибка цитирования Неверный тег
<ref>; для сносокsbне указан текст - ↑ 4,0 4,1 4,2 "The Distance to the 2M1207 System" Шаблон:Webarchive, Eric Mamajek, November 8, 2007. Accessed on line June 15, 2008.
- ↑ Шаблон:Cite journal
- ↑ Шаблон:Cite journal
- ↑ More Sun-like stars may have planetary systems than currently thought Шаблон:Webarchive, library, Origins program, NASA. Accessed on line June 16, 2008.
- ↑ 8,0 8,1 First Ultraviolet Spectrum of a Brown Dwarf: Evidence for H2 Fluorescence and Accretion, John E. Gizis, Harry L. Shipman, and James A. Harvin, Astrophysical Journal 630, #1 (September 2005), pp. L89–L91. Шаблон:Bibcode Шаблон:Doi.
- ↑ Spitzer Observations of Two TW Hydrae Association Brown Dwarfs, Basmah Riaz, John E. Gizis, and Abraham Hmiel, Astrophysical Journal 639, #2 (March 2006), pp. L79–L82. Шаблон:Bibcode Шаблон:Doi.
- ↑ Шаблон:Cite journal
- ↑ Accretion-ejection models of astrophysical jets, R. E. Pudritz, in Accretion Disks, Jets and High-energy Phenomena in Astrophysics, Vassily Beskin, Gilles Henri, Francois Menard, Guy Pelletier, and Jean Dalibard, eds., NATO Advanced Study Institute, Les Houches, session LXXVIII, EDP Sciences/Springer, 2003. Шаблон:ISBN.
- ↑ Шаблон:Cite journal
- ↑ Small Stars Create Big Fuss, Ker Than, May 28, 2007, space.com. Accessed on line June 15, 2008.
- Английская Википедия
- 2M1207
- M-type brown dwarfs
- Centaurus
- TW Hydrae association
- Planetary systems with one confirmed planet
- 2MASS objects
- Free-floating substellar objects
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