| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Delphinus |
| A | |
| Right ascension | 20 30 54.1279 |
| Declination | +06° 25′ 46.338″ |
| Apparent magnitude (V) | +11.98 |
| C | |
| Right ascension | ~20 30 54 |
| Declination | ~+06° 25′ 46″ |
| Apparent magnitude (V) | 15.38 |
| Orbit | |
| Primary | WASP-2A |
| Companion | WASP-2B |
| Semi-major axis (a) | 106″ |
| Characteristics | |
| Spectral type | K1.5V + K2-M3 |
| Apparent magnitude (B) | ~13 |
| Apparent magnitude (V) | ~11.98 |
| Apparent magnitude (J) | 10.166±0.027 |
| Apparent magnitude (H) | 9.752±0.026 |
| Apparent magnitude (K) | 9.632±0.024 |
| Astrometry | |
| Proper motion (μ) | RA: 5.936±0.101 mas/yr Dec.: −48.279±0.082 mas/yr |
| Parallax (π) | 6.4980 ± 0.0686 mas |
| Distance | 502 ± 5 ly (154 ± 2 pc) |
| Details | |
| WASP-2A | |
| Mass | 0.843±0.033 M☉ |
| Radius | 0.821±0.013 R☉ |
| Temperature | 5170±60 K |
| Age | 7.6 −3.3 Gyr |
| WASP-2B | |
| Mass | 0.48 M☉ |
| Temperature | 3523 −19 K |
| Other designations | |
| GSC 00522-01199, 1SWASP J203054.12+062546.4, USNO-B1.0 0964-00543604, 2MASS J20305413+0625463, UCAC2 34018636, Gaia DR2 1748596020745038208, V357 Del | |
| Database references | |
| SIMBAD | data |
WASP-2 is a binary star system in the Delphinus constellation located about 500 light-years away. The primary is magnitude 12 orange dwarf star, orbited by red dwarf star on wide orbit. The star system shows an infrared excess noise of unknown origin.
Planetary system
This star has one extrasolar planet WASP-2b, detected by the SuperWASP project in 2006.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.882±0.027 MJ | 0.0308±0.0004 | 2.15222144 (± 4e-07) | 0 | — | 1.06±0.024 RJ |
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.
The re-examination of the WASP-2 spectrum in 2015, have resulted in the measurement of stellar companion temperature equal to 3513±28 K, and angular separation of 0.73 arc second.
See also
Notes
- The secondary star is identified with a "C" suffix so as to not confuse it with the planetary designation suffix "b".
References
- ^ 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.
- ^ 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.
- ^ "WASP-2". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-05-04.
- ^ 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
- 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
- ^ 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
- 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
- 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.
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