WASP-2
WASP-2 is a magnitude 12 orange dwarf star located about 500 light-years away in the Delphinus constellation.[3] It shows an infrared excess noise of unknown origin.[5]
| 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] |
| Characteristics | |
| Spectral type | K1V[4]/M[1] |
| 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 | |
| Mass | 0.77[1]/0.48[1] M☉ |
| Radius | 0.834 ±0.08 R☉ |
| Temperature | 5200 ±200 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.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.847 (± 0.045) MJ | 0.03138 (± 0.011) | 2.15222144 (± 4e-07) | 0 | — | — |
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[6]
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.
- 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.
- 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.
- EXTRASOLAR PLANET TRANSITS OBSERVED AT KITT PEAK NATIONAL OBSERVATORY, 2012, arXiv:1202.2799
- FRIENDS OF HOT JUPITERS III:AN INFRARED SPECTROSCOPIC SEARCH FOR LOW-MASS STELLAR COMPANIONS, 2015, arXiv:1510.08062
External links
- "WASP-2". Exoplanets. Retrieved 2009-05-04.
