GQ Lupi b

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GQ Lupi b
Exoplanet Comparison GQ Lupi b.png
Size comparison of GQ Lupi b (at Neuhäuser et al. estimate) with Jupiter. Jupiter 140000km GQ lupi b 460000km
Discovered byNeuhäuser et al.
Discovery siteParanal Observatory,
Discovery dateApril 2005
Orbital characteristics
StarGQ Lupi
Physical characteristics
Mean radius
1.8[1] RJ
Mass1 – 36[2][3] MJ
Temperature2650 ± 100,[3] (2050±350–2400)[4] K

GQ Lupi b is a possible extrasolar planet, brown dwarf or Sub-brown dwarf orbiting the star GQ Lupi. Its discovery was announced in April 2005. Along with 2M1207b, this was one of the first extrasolar planet candidates to be directly imaged. The image was made with the VLT telescope at Paranal Observatory, Chile on June 25, 2004.[5]

VLT NACO image, taken in the Ks-band, of GQ Lupi. The feeble point of light to the right of the star is the newly found cold companion. It is 250 times fainter than the star itself and it located 0.73 arc second west. At the distance of GQ Lupi, this corresponds to a distance of roughly 100 AU. North is up and East is to the left.

GQ Lupi b has a spectral type between M6 and L0, corresponding to a temperature between 2,050 and 2,650 kelvins.[3] Located at a projected distance of about 100 AU from its companion star, giving it an orbital period of perhaps about 1,200 years, it is believed to be several times more massive than Jupiter. Because the theoretical models which are used to predict planetary masses for objects in young star systems like GQ Lupi b are still tentative, the mass cannot be precisely specified — models place GQ Lupi b's mass anywhere between a few Jupiter masses and 36 Jupiter masses.[3] At the highest end of this range, GQ Lupi b could be classified as a small brown dwarf, but at the lowest end of this range, it could rather be classified as an extremely large Jupiter-like exoplanet than a brown dwarf.

If classified as an exoplanet, with a maximum radius of 6.5 times that of Jupiter (RJ) (or 930,000 km in diameter), this would make GQ Lupi b one of largest exoplanets discovered, although the size of the planet is shrinking as it evolves.

As of 2006, the International Astronomical Union Working Group on Extrasolar Planets described GQ Lupi b as a "possible planetary-mass companion to a young star."[6]
GQ Lupi b is listed as "confirmed planet" as in 2020.[7]

See also[edit]


  1. ^ [1]
  2. ^ Planet : GQ Lup b, Extrasolar Planets Encyclopaedia. Accessed on line June 13, 2008
  3. ^ a b c d Astrometric and photometric monitoring of GQ Lupi and its sub-stellar companion, Ralph Neuhäuser, Markus Mugrauer, Andreas Seifahrt, Tobias Schmidt, and Nikolaus Vogt, Astronomy and Astrophysics 484, #1 (2008), pp. 281–291. doi:10.1051/0004-6361:20078493. Bibcode:2008A&A...484..281N
  4. ^ Zhou, Yifan; Herczeg, Gregory J; Kraus, Adam L; Metchev, Stanimir; Cruz, Kelle L (2014). "Accretion onto Planetary Mass Companions of Low-mass Young Stars". The Astrophysical Journal Letters. 783: L17. arXiv:1401.6545. Bibcode:2014ApJ...783L..17Z. doi:10.1088/2041-8205/783/1/L17.
  5. ^ Is this a Brown Dwarf or an Exoplanet? New Young Sub-stellar Companion Imaged with the VLT Archived 2008-05-07 at the Wayback Machine, ESO Press Release 09/05, April 7, 2005. Accessed on line June 13, 2008.
  6. ^ Lists of Extrasolar Planets Archived 2013-10-29 at the Wayback Machine, IAU Working Group on Extrasolar Planets, August 28, 2006. Accessed on line June 13, 2008.
  7. ^ GQ Lup

External links[edit]

Media related to GQ Lupi b at Wikimedia Commons