WASP-2
WASP-2 is a binary star system in the Delphinus constellation located about 500 light-years away.[3] The primary is magnitude 12 orange dwarf star, orbited by red dwarf star on wide orbit.[4][7] The star system shows an infrared excess noise of unknown origin.[8]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Delphinus |
| A[1] | |
| Right ascension | 20h 30m 54.1279s[2] |
| Declination | +06° 25′ 46.338″[2] |
| Apparent magnitude (V) | +11.98[3] |
| C[a 1] | |
| Right ascension | ~20h 30m 54s[1] |
| Declination | ~+06° 25′ 46″[1] |
| Apparent magnitude (V) | 15.38[1] |
| Orbit[4] | |
| Primary | WASP-2A |
| Companion | WASP-2B |
| Semi-major axis (a) | 106″ |
| Characteristics | |
| Spectral type | K1.5V + K2-M3[5] |
| 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] |
| Astrometry | |
| Proper motion (μ) | RA: 5.936±0.101[2] mas/yr Dec.: −48.279±0.082[2] mas/yr |
| Parallax (π) | 6.4980 ± 0.0686[2] mas |
| Distance | 502 ± 5 ly (154 ± 2 pc) |
| Details[6] | |
| WASP-2A | |
| Mass | 0.843±0.033 M☉ |
| Radius | 0.821±0.013 R☉ |
| Temperature | 5170±60 K |
| Age | 7.6+2.5 −3.3 Gyr |
| WASP-2B | |
| Mass | 0.48[1] M☉ |
| Temperature | 3523+28 −19 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
Planetary system
This star has one extrasolar planet WASP-2b, detected by the SuperWASP project in 2006.[9]
| 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.[1]
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[10]
Notes
- The secondary star is identified with a "C" suffix so as to not confuse it with the planetary designation suffix "b".[1]
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, 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, 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, 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, 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, doi:10.1088/0004-637X/814/2/148, S2CID 11525988
External links
- "WASP-2". Exoplanets. Retrieved 2009-05-04.
