GQ Lupi

GQ Lupi is a T Tauri variable star approximately 495 light-years away[3] in the constellation of Lupus.[5] The star is young and has about 70% of the Sun's mass.[7]

GQ Lupi

A visual band light curve for GQ Lupi. The main plot (from ASAS data[1]), shows the long-term variability, and the inset plot (adapted from Broeg et al.[2]) shows the short-term periodic brightness variation.
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Lupus
Right ascension 15h 49m 12.1056s[3]
Declination −35° 39′ 05.0540″[3]
Apparent magnitude (V) 11.40[4]
Characteristics
Spectral type K7V[4]
B−V color index 0.96[4]
Variable type T Tauri variable[5]
Astrometry
Proper motion (μ) RA: −14.257±0.097[3] mas/yr
Dec.: −23.596±0.066[3] mas/yr
Parallax (π)6.5868 ± 0.0473 mas[3]
Distance495 ± 4 ly
(152 ± 1 pc)
Absolute magnitude (MV)~5[6]
Details
Mass0.7[7] M☉
Age<2 million[7] years
Other designations
CD−35°10525, GQ Lup[4]
Database references
SIMBADdata

Possible planetary system
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.

In 2005, Ralph Neuhäuser and his colleagues reported a substellar object, GQ Lupi b, orbiting the star. 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. Depending on its mass and the definition of a planet, GQ Lupi b may or may not be considered a planet.[8] 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."[9] GQ Lupi b is listed as "confirmed planet" as in 2020.[10]

In 2020, another low-mass companion of GQ Lupi was discovered at a separation distance of about 16 arcseconds, or 2400 AU. Designated 2MASS J15491331-3539118 under the 2MASS catalogue, it is likely a young stellar object that is gravitationally bound to its primary star. It is estimated to be approximately 15% the Sun's mass and 21% the Sun's radius. It has an effective temperature of about 3190 K, indicating that it is a red dwarf with the spectral type M4.[11]

The GQ Lupi system
Companion MassObserved separation
(AU)
b1–36[5][12] MJ103 ± 37[12]

References
  1. "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
  2. Broeg, C.; Schmidt, T. O. B.; Guenther, E.; Gaedke, A.; Bedalov, A.; Neuhäuser, R.; Walter, F. M. (June 2007). "Rotational period of GQ Lupi". Astronomy and Astrophysics. 468 (3): 1039–1044. Bibcode:2007A&A...468.1039B. doi:10.1051/0004-6361:20066793.
  3. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  4. "V* GQ Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved June 13, 2008.
  5. Astrometric and photometric monitoring of GQ Lupi and its sub-stellar companion, Ralph Neuhaeuser, 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
  6. From parallax and apparent magnitude.
  7. First image of exoplanet orbiting Sun-like star, Kelly Young, April 4, 2005, NewScientist.com news service. Accessed on line June 13, 2008.
  8. 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.
  9. 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.
  10. openexoplanetcatalogue.com GQ Lup
  11. Alcalá, J. M.; et al. (2020). "2MASS J15491331-3539118: a new low-mass wide companion of the GQ Lup system". Astronomy & Astrophysics. 635: L1. arXiv:2001.10879. Bibcode:2020A&A...635L...1A. doi:10.1051/0004-6361/201937309. S2CID 210942917.
  12. Planet : GQ Lup b, Extrasolar Planets Encyclopaedia. Accessed on line June 13, 2008
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