| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Delphinus |
| A[1] | |
| Right ascension | 20h 30m 54.1300s[2] |
| Declination | +06° 25′ 46.37″[2] |
| Apparent magnitude (V) | +11.98[2] |
| Ca | |
| Right ascension | ~20h 30m 54s[1] |
| Declination | ~+06° 25′ 46″[1] |
| Apparent magnitude (V) | 15.38[1] |
| Characteristics | |
| Spectral type | K1V[3]/M[1] |
| Apparent magnitude (B) | ~13[2] |
| Apparent magnitude (V) | ~11.98[2] |
| Apparent magnitude (J) | 10.166±0.027[2] |
| Apparent magnitude (H) | 9.752±0.026[2] |
| Apparent magnitude (K) | 9.632±0.024[2] |
| Astrometry | |
| Proper motion (μ) | RA: 3.0[2] mas/yr Dec.: -53.1[2] mas/yr |
| Distance | 469 ly (144 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 |
WASP-2 is a magnitude 12 orange dwarf star located about 469 light-years away in the Delphinus constellation.[2]
Contents |
This star has one extrasolar planet WASP-2b, detected by the SuperWASP project in 2006.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity |
|---|---|---|---|---|
| b | 0.847 (± 0.045) MJ | 0.03138 (± 0.011) | 2.15222144 (± 4e-07) | 0 |
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]