Qatar-2
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo[1] |
| Right ascension | 13h 50m 37.4100s[2] |
| Declination | −06° 48′ 14.422″[2] |
| Apparent magnitude (V) | 13.3[3] |
| Characteristics | |
| Spectral type | K5V[4] |
| Astrometry | |
| Radial velocity (Rv) | −23.55[5] km/s |
| Proper motion (μ) | RA: −88.171[2] mas/yr Dec.: −15.187[2] mas/yr |
| Parallax (π) | 5.4023±0.0195 mas[2] |
| Distance | 604 ± 2 ly (185.1 ± 0.7 pc) |
| Details[6][3] | |
| Mass | 0.727±0.024 M☉ |
| Radius | 0.7033±0.0080 R☉ |
| Surface gravity (log g) | 4.601±0.018 cgs |
| Temperature | 4,645±50 K |
| Metallicity [Fe/H] | 0.13±0.1[7] dex |
| Rotation | 18.0±0.2 |
| Rotational velocity (v sin i) | 2.0±0.2 km/s |
| Age | 9 Gyr |
| Other designations | |
| Gaia DR2 3620030644476623616, GSC 04974-00112, 2MASS J13503740-0648145[8] | |
| Database references | |
| SIMBAD | data |
Qatar-2 is a K-type main-sequence star about 595 light-years away in the constellation of Virgo. The star is much older than Sun, and has a concentration of heavy elements similar to solar abundance.[3] The star features a numerous and long-lived starspots,[6] and belongs to a peculiar variety of inflated K-dwarfs with strong magnetic activity inhibiting internal convection.[9]
Planetary system
[edit]In 2011 a transiting superjovian planet Qatar-2b was detected by the Qatar Exoplanet Survey.[3] The planet has a large measured temperature difference between dayside 1,368±32 K and nightside 724±135 K.[10] The planetary orbit is well aligned with the equatorial plane of the star,[7] misalignment angle equal to 4.3°±4.5°.[11] No orbital decay was detected.[12] The color of planetary atmosphere is blue due to Rayleigh scattering of light,[11] and albedo is very low, being below 0.06.[12]
An additional massive companion on wide orbit was suspected in 2011,[3] but search utilizing transit-timing variation method has yielded zero results in 2017.[6]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.466±0.062 MJ | 0.02136±0.00024 | 1.33711677±0.00000010 | 0 | 88.99±0.20° | 1.115±0.013 RJ |
References
[edit]- ^ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object 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.
- ^ a b c d e f Bryan, Marta L.; Alsubai, Khalid A.; Latham, David W.; Parley, Neil R.; Collier Cameron, Andrew; Quinn, Samuel N.; Carter, Joshua A.; Fulton, Benjamin J.; Berlind, Perry; Brown, Warren R.; Buchhave, Lars A.; Calkins, Michael L.; Esquerdo, Gilbert A.; Fűrész, Gábor; Jørgensen, Uffe Gråe; Horne, Keith D.; Stefanik, Robert P.; Street, Rachel A.; Torres, Guillermo; West, Richard G.; Dominik, Martin; Harpsøe, Kennet B. W.; Liebig, Christine; Calchi Novati, Sebastiano; Ricci, Davide; Skottfelt, Jesper F. (2011), "Qatar-2: A K dwarf orbited by a transiting hot Jupiter and a more massive companion in an outer orbit", The Astrophysical Journal, 750: 84, arXiv:1110.5912, doi:10.1088/0004-637X/750/1/84, S2CID 118627543
- ^ Dressing, Courtney D.; Newton, Elisabeth R.; Schlieder, Joshua E.; Charbonneau, David; Knutson, Heather A.; Vanderburg, Andrew; Sinukoff, Evan (2017). "Characterizing K2 Candidate Planetary Systems Orbiting Low-mass Stars. I. Classifying Low-mass Host Stars Observed during Campaigns 1-7". The Astrophysical Journal. 836 (2): 167. arXiv:1701.00586. Bibcode:2017ApJ...836..167D. doi:10.3847/1538-4357/836/2/167.
- ^ 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.
- ^ a b c d Močnik, T.; Southworth, J.; Hellier, C. (2017), "Recurring sets of recurring starspot occultations on exoplanet-host Qatar-2", Monthly Notices of the Royal Astronomical Society, 471 (1): 394–403, arXiv:1608.07524, Bibcode:2017MNRAS.471..394M, doi:10.1093/mnras/stx1557, S2CID 119240651
- ^ a b Esposito, M.; Covino, E.; Desidera, S.; Mancini, L.; Nascimbeni, V.; Zanmar Sanchez, R.; Biazzo, K.; Lanza, A. F.; Leto, G.; Southworth, J.; Bonomo, A. S.; Suárez Mascareño, A.; Boccato, C.; Cosentino, R.; Claudi, R. U.; Gratton, R.; Maggio, A.; Micela, G.; Molinari, E.; Pagano, I.; Piotto, G.; Poretti, E.; Smareglia, R.; Sozzetti, A.; Affer, L.; Anderson, D. R.; Andreuzzi, G.; Benatti, S.; Bignamini, A.; et al. (2017), "The GAPS Programme with HARPS-N at TNG. XIII. The orbital obliquity of three close-in massive planets hosted by dwarf K-type stars: WASP-43, HAT-P-20 and Qatar-2", Astronomy & Astrophysics, 601: A53, arXiv:1702.03136, Bibcode:2017A&A...601A..53E, doi:10.1051/0004-6361/201629720, S2CID 119341241
- ^ "Qatar 2". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2025-05-05.
- ^ Maxted, P. F. L.; Serenelli, A. M.; Southworth, J. (2015), "A comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars", Astronomy & Astrophysics, 577: A90, arXiv:1503.09111, Bibcode:2015A&A...577A..90M, doi:10.1051/0004-6361/201525774, S2CID 53324330
- ^ May, E. M.; Stevenson, K. B.; Bean, Jacob L.; Bell, Taylor J.; Cowan, Nicolas B.; Dang, Lisa; Desert, Jean-Michel; Fortney, Jonathan J.; Keating, Dylan; Kempton, Eliza M.-R.; Komacek, Thaddeus D.; Lewis, Nikole K.; Mansfield, Megan; Morley, Caroline; Parmentier, Vivien; Rauscher, Emily; Swain, Mark R.; Zellem, Robert T.; Showman, Adam (2022), "A New Analysis of Eight Spitzer Phase Curves and Hot Jupiter Population Trends: Qatar-1b, Qatar-2b, WASP-52b, WASP-34b, and WASP-140b", The Astronomical Journal, 163 (6): 256, arXiv:2203.15059, Bibcode:2022AJ....163..256M, doi:10.3847/1538-3881/ac6261, S2CID 247778438
- ^ a b Mancini, L.; Southworth, J.; Ciceri, S.; Tregloan-Reed, J.; Crossfield, I.; Nikolov, N.; Bruni, I.; Zambelli, R.; Henning, Th. (2014), "Physical properties, starspot activity, orbital obliquity, and transmission spectrum of the Qatar-2 planetary system from multi-colour photometry", Monthly Notices of the Royal Astronomical Society, 443 (3): 2391, arXiv:1406.6714, Bibcode:2014MNRAS.443.2391M, doi:10.1093/mnras/stu1286, S2CID 119203713
- ^ a b Dai, Fei; Winn, Joshua N.; Yu, Liang; Albrecht, Simon (2016), "The Stellar Obliquity, Planet Mass, and Very Low Albedo of Qatar-2 from K2 Photometry", The Astronomical Journal, 153: 40, arXiv:1609.01314, doi:10.3847/1538-3881/153/1/40, S2CID 56019135
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