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[3] |
| GQ Lupi A | |
| Right ascension | 15h 49m 12.1054s[4] |
| Declination | −35° 39′ 05.058″[4] |
| Apparent magnitude (V) | 11.3–14.3[3] |
| GQ Lupi C | |
| Right ascension | 15h 49m 13.3078s[5] |
| Declination | −35° 39′ 11.761″[5] |
| Apparent magnitude (V) | 19.72[6] |
| Characteristics | |
| GQ Lupi A | |
| Evolutionary stage | Pre-main sequence[7] |
| Spectral type | K7Ve[8] |
| B−V color index | 0.96[9] |
| Variable type | T Tauri variable[3] |
| GQ Lupi C | |
| Evolutionary stage | Pre-main sequence[10] |
| Spectral type | M4[10] |
| Astrometry | |
| GQ Lupi A | |
| Radial velocity (Rv) | −3.6±1.3[11] km/s |
| Proper motion (μ) | RA: −14.133[4] mas/yr Dec.: −23.329[4] mas/yr |
| Parallax (π) | 6.4893±0.0289 mas[4] |
| Distance | 503 ± 2 ly (154.1 ± 0.7 pc) |
| GQ Lupi C | |
| Proper motion (μ) | RA: −14.508[5] mas/yr Dec.: −23.862[5] mas/yr |
| Parallax (π) | 5.7229±0.3559 mas[5] |
| Distance | 570 ± 40 ly (170 ± 10 pc) |
| Position (relative to GQ Lupi A) | |
| Component | GQ Lupi C |
| Projected separation | 2430[10] AU |
| Details | |
| GQ Lupi A | |
| Mass | 1.03±0.05[12] M☉ |
| Radius | 1.75+0.06 −0.07[13] R☉ |
| Luminosity | 1.05+0.27 −0.22[14] L☉ |
| Surface gravity (log g) | 3.7[15] cgs |
| Temperature | 4306±35[13] K |
| Rotation | 8.45±0.20[2] days |
| Rotational velocity (v sin i) | 5.66±0.02[16] km/s |
| Age | 2.8+1.8 −1.1[14] Myr |
| GQ Lupi C | |
| Mass | 0.15±0.05[10] M☉ |
| Radius | 0.87±0.20[10] R☉ |
| Luminosity | 0.07±0.02[10] L☉ |
| Temperature | 3230±101[10] K |
| Rotational velocity (v sin i) | 13±6[10] km/s |
| Other designations | |
| GQ Lup, WDS J15492-3539[17] | |
| GQ Lupi A: CD−35°10525[17] | |
| GQ Lupi C: 2MASS J15491331-3539118[18] | |
| Database references | |
| SIMBAD | GQ Lupi A |
| SIMBAD | GQ Lupi C |
GQ Lupi is a possible binary star system in the constellation Lupus. The system is young, with an age of a few million years (for comparison, the Solar System is roughly 4.6 billion years old), and is within the Lupus I star-forming region,[10] which is part of the Scorpius–Centaurus association.[19]
Stellar system
The primary component is designated GQ Lupi A, and was referred to simply as GQ Lupi before the discovery of the secondary stellar companion. It is a T Tauri star, with a variable apparent magnitude ranging from 11.3 at brightest and 14.3 at faintest.[3] The spectral type is K7Ve, with the 'e' indicating emission lines in the spectrum,[8] which in classical T Tauri stars such as GQ Lupi results from an extensive surrounding disk.[3] The star has 1.03 times the mass of the Sun[12] and 1.75 times the Sun's radius, with an effective temperature of 4306 K.[12] Its age is estimated at 2.8+1.8
−1.1 million years.[14] This star is surrounded by a circumstellar disk with a major axis of 59±12 AU.[12]
In 2020, a low-mass companion of GQ Lupi was discovered at a separation of about 16 arcseconds, or 2400 AU. Designated 2MASS J15491331-3539118 in the 2MASS catalogue, it is a young stellar object that is likely gravitationally bound to the primary star, although the low quality of the companion's proper motion and parallax does not allow for a definitive conclusion. It is estimated to be approximately 15% the Sun's mass and 87% the Sun's radius. It has an effective temperature of about 3230 K, indicating that it is a red dwarf with the spectral type M4.[10]
Substellar companion
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.[20] 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".[21]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ~10 – 40[16] MJ | 97.7+8.9 −7.1[22] |
921+159 −124[a] |
0.35+0.10 −0.09[22] |
48+4 −5[22]° |
3.7±0.7[14] RJ |
Notes
- ^ Calculated using P2 = a3 / Mtot,
where a is the semi-major axis in astronomical units, Mtot is the total mass of the system, in M☉, and P is the period in years. Upper error bar calculated with the −7.14 uncertainty in a and +0.07 in Mtot. Lower error bar calculated with the +8.92 uncertainty in a and −0.06 in Mtot.
References
- ^ "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
- ^ a b 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. ISSN 0004-6361.
- ^ a b c d e "VSX : Detail for GQ Lup". vsx.aavso.org. Retrieved 2026-02-07.
- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ Tokovinin, Andrei (2018). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series. 235 (1): 6. arXiv:1712.04750. Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5.
- ^ Ducourant, C.; Teixeira, R.; Périé, J. P.; Lecampion, J. F.; Guibert, J.; Sartori, M. J. (2005). "Pre-main sequence star Proper Motion Catalogue". Astronomy and Astrophysics. 438 (2): 769. Bibcode:2005A&A...438..769D. doi:10.1051/0004-6361:20052788.
- ^ a b Herbig, G. H. (June 1977). "Radial velocities and spectral types of T Tauri stars". The Astrophysical Journal. 214: 747–758. Bibcode:1977ApJ...214..747H. doi:10.1086/155304. ISSN 0004-637X.
- ^ "V* GQ Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved June 13, 2008.
- ^ a b c d e f g h i j 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.
- ^ Frasca, A.; Biazzo, K.; Alcalá, J. M.; Manara, C. F.; Stelzer, B.; Covino, E.; Antoniucci, S. (2017-06-01). "X-shooter spectroscopy of young stellar objects in Lupus - Atmospheric parameters, membership, and activity diagnostics". Astronomy & Astrophysics. 602: A33. arXiv:1703.01251. Bibcode:2017A&A...602A..33F. doi:10.1051/0004-6361/201630108. ISSN 0004-6361.
- ^ a b c d MacGregor, Meredith A.; Wilner, David J.; Czekala, Ian; Andrews, Sean M.; Dai, Y. Sophia; Herczeg, Gregory J.; Kratter, Kaitlin M.; Kraus, Adam L.; Ricci, Luca; Testi, Leonardo (2017-01-16). "ALMA Measurements of Circumstellar Material in the GQ Lup System". The Astrophysical Journal. 835 (1): 17. arXiv:1611.06229. Bibcode:2017ApJ...835...17M. doi:10.3847/1538-4357/835/1/17. ISSN 0004-637X.
- ^ a b Kammerer, J.; Winterhalder, T. O.; Lacour, S.; Stolker, T.; Marleau, G.-D.; Balmer, W. O.; Moore, A. F.; Piscarreta, L.; Toci, C. (2025-11-02). "The ExoGRAVITY survey: A K-band spectral library of giant exoplanet and brown dwarf companions". The Astrophysical Journal. 704: A318. arXiv:2510.08691. Bibcode:2025A&A...704A.318K. doi:10.1051/0004-6361/202556860.
- ^ a b c d Xuan, Jerry W.; Hsu, Chih-Chun; Finnerty, Luke; Wang, Jason; Ruffio, Jean-Baptiste; Zhang, Yapeng; Knutson, Heather A.; Mawet, Dimitri; Mamajek, Eric E.; Inglis, Julie; Wallack, Nicole L.; Bryan, Marta L.; Blake, Geoffrey A.; Mollière, Paul; Hejazi, Neda (2024-07-01). "Are These Planets or Brown Dwarfs? Broadly Solar Compositions from High-resolution Atmospheric Retrievals of ∼10–30 MJup Companions". The Astrophysical Journal. 970 (1): 71. arXiv:2405.13128. Bibcode:2024ApJ...970...71X. doi:10.3847/1538-4357/ad4796. ISSN 0004-637X.
- ^ Donati, J.-F.; Gregory, S. G.; Alencar, S. H. P.; Hussain, G.; Bouvier, J.; Dougados, C.; Jardine, M. M.; Ménard, F.; Romanova, M. M. (2012-09-05). "Magnetometry of the classical T Tauri star GQ Lup: non-stationary dynamos and spin evolution of young Suns". Monthly Notices of the Royal Astronomical Society. 425 (4): 2948–2963. arXiv:1206.1770. Bibcode:2012MNRAS.425.2948D. doi:10.1111/j.1365-2966.2012.21482.x. ISSN 0035-8711.
- ^ a b González Picos, D.; Snellen, I. A. G.; de Regt, S.; Landman, R.; Zhang, Y.; Gandhi, S.; Sánchez-López, A. (January 2025). "The ESO SupJup Survey: IV. Unveiling the carbon isotope ratio of GQ Lup B and its host star". Astronomy & Astrophysics. 693: A298. arXiv:2501.01789. Bibcode:2025A&A...693A.298G. doi:10.1051/0004-6361/202451936. ISSN 0004-6361.
- ^ a b "GQ Lup". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ "V* GQ Lup C". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ Comerón, F. (2008). "The Lupus Clouds". Handbook of Star Forming Regions, Volume II. 5: 295. Bibcode:2008hsf2.book..295C.
- ^ 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.
- ^ 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.
- ^ a b c Venkatesan, Vidya; Blunt, S.; Wang, J. J.; Lacour, S.; Marleau, G.-D.; Coleman, G. A. L.; Guerrero, L.; Balmer, W. O.; Pueyo, L.; Stolker, T.; Kammerer, J.; Pourré, N.; Nowak, M.; Rickman, E.; Sivaramakrishnan, A. (2025-10-24). "Constraints on the Orbit of the Young Substellar Companion GQ Lup B from High-resolution Spectroscopy and VLTI/GRAVITY Astrometry". The Astrophysical Journal. 993 (1): 69. arXiv:2509.20621. Bibcode:2025ApJ...993...69V. doi:10.3847/1538-4357/ae0c15. ISSN 0004-637X.
External links
- Guenther, E. W.; Neuhäuser, R.; Wuchterl, G.; Mugrauer, M.; Bedalov, A.; Hauschildt, P. H. (2005). "The low-mass companion of GQ Lup". Astronomische Nachrichten. 326 (10): 958–963. arXiv:astro-ph/0510794. Bibcode:2005AN....326..958G. doi:10.1002/asna.200510461.
- Neuhaeuser, Ralph (2005). "Homogeneous comparison of directly detected planet candidates: GQ Lup, 2M1207, AB Pic". arXiv:astro-ph/0509906.
- Young, Kelly (2005-04-04). "First image of exoplanet orbiting Sun-like star". New Scientist. Retrieved 2008-06-09.
- "Telescopes see 'distant planet'". BBC News. 2005-04-04. Retrieved 2008-06-09.
- Britt, Robert Roy (2005-04-30). "Fresh Debate over First Photo of Extrasolar Planet". SPACE.com. Retrieved 2008-06-09.