WASP-2
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Delphinus |
| A[1] | |
| Right ascension | 20h 30m 54.1282s[2] |
| Declination | +06° 25′ 46.341″[2] |
| Apparent magnitude (V) | +11.98[3] |
| C[a 1] | |
| Right ascension | ~20h 30m 54s[1] |
| Declination | ~+06° 25′ 46″[1] |
| Characteristics | |
| Spectral type | K1.5V + K2-M3[4] |
| Apparent magnitude (B) | ~13[3] |
| Apparent magnitude (V) | ~11.98[3] |
| Apparent magnitude (J) | 10.166±0.027[3] |
| Apparent magnitude (H) | 9.752±0.026[3] |
| Apparent magnitude (K) | 9.632±0.024[3] |
| Variable type | planetary transit[5] |
| Astrometry | |
| Radial velocity (Rv) | −27.70±0.46[2] km/s |
| Proper motion (μ) | RA: 5.631 mas/yr[2] Dec.: −48.491 mas/yr[2] |
| Parallax (π) | 6.5777±0.0270 mas[2] |
| Distance | 496 ± 2 ly (152.0 ± 0.6 pc) |
| Orbit[6] | |
| Primary | WASP-2A |
| Companion | WASP-2B |
| Semi-major axis (a) | 106″ |
| Details | |
| WASP-2A | |
| Mass | 0.843±0.033[7] M☉ |
| Radius | 0.821±0.013[7] R☉ |
| Luminosity | 0.507+0.023 −0.029[8] L☉ |
| Surface gravity (log g) | 4.536±0.015[7] cgs |
| Temperature | 5170±60[7] K |
| Metallicity [Fe/H] | 0.1±0.2[9] dex |
| Rotational velocity (v sin i) | 0.9±0.5[9] km/s |
| Age | 7.6+2.5 −3.3[7] Gyr |
| WASP-2B | |
| Mass | 0.40±0.02[7] M☉ |
| Temperature | 3523+28 −19[7] K |
| Other designations | |
| V357 Del, TOI-5797, TIC 374530847, WASP-2, GSC 00522-01199, 2MASS J20305413+0625463, 1SWASP J203054.12+062546.4, USNO-B1.0 0964-00543604, UCAC2 34018636[3] | |
| Database references | |
| SIMBAD | A |
| B | |
| Exoplanet Archive | data |
WASP-2 is a binary star system located about 496 light-years away in the Delphinus constellation.[3] The primary is a magnitude 12 orange dwarf star, orbited by a red dwarf star on a wide orbit.[6][10] The star system shows an infrared excess noise of unknown origin.[11]
The primary star hosts one known exoplanet, WASP-2b.[12] Since the planet transits the star, the star is classified as a planetary transit variable and has received the variable star designation V357 Delphini.[5]
Binary star
In 2008 a study was undertaken of fourteen stars with exoplanets that were originally discovered using the transit method through relatively small telescopes. These systems were re-examined with the 2.2 m (87 in) reflector telescope at the Calar Alto Observatory in Spain. This star system, along with two others, was determined to be a previously unknown binary star system. The previously unknown secondary star is a dim magnitude 15 M-type star separated by about 111 AU from the primary, appearing offset from the primary by about one arc second in the images. This discovery resulted in a recalculation of parameters for both the planet and the primary star.[1]
A re-examination of the WASP-2 spectrum in 2015 resulted in the measurement of the stellar companion's temperature as 3513±28 K, and an angular separation of 0.73 arcseconds.[13]
Planetary system
The primary star has one exoplanet, WASP-2b, a hot Jupiter detected by the SuperWASP project in 2006 using the transit method.[12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.892±0.027 MJ | 0.0308±0.0004 | 2.15222163(42) | <0.013 | 84.81+0.35 −0.27° |
1.060±0.024 RJ |
See also
Notes
References
- ^ a b c d e Daemgen; et al. (2009). "Binarity of transit host stars - Implications for planetary parameters" (PDF). Astronomy and Astrophysics. 498 (2): 567–574. arXiv:0902.2179. Bibcode:2009A&A...498..567D. doi:10.1051/0004-6361/200810988. S2CID 9893376.
- ^ 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 g h "WASP-2". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-05-04.
- ^ Wöllert, Maria; Brandner, Wolfgang; Bergfors, Carolina; Henning, Thomas (2015), "A Lucky Imaging search for stellar companions to transiting planet host stars", Astronomy & Astrophysics, 575: A23, arXiv:1507.01938, Bibcode:2015A&A...575A..23W, doi:10.1051/0004-6361/201424091, S2CID 119250579
- ^ a b "V357 Del". General Catalog of Variable Stars - VizieR. Retrieved 3 April 2025.
- ^ a b Quarles, Billy; Li, Gongjie; Kostov, Veselin; Haghighipour, Nader (2020), "Orbital stability of circumstellar planets in binary systems", The Astronomical Journal, 159 (3): 80, arXiv:1912.11019, Bibcode:2020AJ....159...80Q, doi:10.3847/1538-3881/ab64fa, S2CID 209444271
- ^ a b c d e f g h Southworth, J.; Bohn, A. J.; Kenworthy, M. A.; Ginski, C.; Mancini, L. (2020), "A multiplicity study of transiting exoplanet host stars. II.Revised properties of transiting planetary systems with companions", Astronomy & Astrophysics, A74: 635, arXiv:2001.08225, Bibcode:2020A&A...635A..74S, doi:10.1051/0004-6361/201937334, S2CID 210860775
- ^ Addison, Brett; Wright, Duncan J.; et al. (November 2019). "Minerva-Australis. I. Design, Commissioning, and First Photometric Results". Publications of the Astronomical Society of the Pacific. 131 (1005): 115003. arXiv:1901.11231. Bibcode:2019PASP..131k5003A. doi:10.1088/1538-3873/ab03aa.
- ^ a b c Bonomo, A. S.; Desidera, S.; et al. (June 2017). "The GAPS Programme with HARPS-N at TNG. XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets". Astronomy & Astrophysics. 602: A107. arXiv:1704.00373. Bibcode:2017A&A...602A.107B. doi:10.1051/0004-6361/201629882.
- ^ Precise Differential Analysis of Stellar Metallicities: Application to Solar Analogs Including 16 Cyg A and B
- ^ Sada, Pedro V.; Deming, Drake; Jennings, Donald E.; Jackson, Brian k.; Hamilton, Catrina M.; Fraine, Jonathan; Peterson, Steven W.; Haase, Flynn; Bays, Kevin; Lunsford, Allen; o'Gorman, Eamon (2012), "Extrasolar Planet Transits Observed at Kitt Peak National Observatory", Publications of the Astronomical Society of the Pacific, 124 (913): 212–229, arXiv:1202.2799, Bibcode:2012PASP..124..212S, doi:10.1086/665043, S2CID 29665395
- ^ a b Cameron, A. Collier; et al. (2007). "WASP-1b and WASP-2b: two new transiting exoplanets detected with SuperWASP and SOPHIE". Monthly Notices of the Royal Astronomical Society. 375 (3): 951–957. arXiv:astro-ph/0609688. Bibcode:2007MNRAS.375..951C. doi:10.1111/j.1365-2966.2006.11350.x. S2CID 735515.
- ^ Piskorz, Danielle; Knutson, Heather A.; Ngo, Henry; Muirhead, Philip S.; Batygin, Konstantin; Crepp, Justin R.; Hinkley, Sasha; Morton, Timothy D. (2015), "Friends of Hot Jupiters. III. An Infrared Spectroscopic Search for Low-Mass Stellar Companions", The Astrophysical Journal, 814 (2): 148, arXiv:1510.08062, Bibcode:2015ApJ...814..148P, doi:10.1088/0004-637X/814/2/148, S2CID 11525988
External links
- "WASP-2". Exoplanets. Archived from the original on 2012-04-01. Retrieved 2009-05-04.
