WASP-2

Last updated
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  (J)10.166±0.027 [5]
Apparent magnitude  (H)9.752±0.026 [5]
Apparent magnitude  (K)9.632±0.024 [5]
Variable type planetary transit [6]
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 [7]
PrimaryWASP-2A
CompanionWASP-2B
Semi-major axis (a)106″
Details
WASP-2A
Mass 0.843±0.033 [8]   M
Radius 0.821±0.013 [8]   R
Luminosity 0.507+0.023
−0.029
[9]   L
Surface gravity (log g)4.536±0.015 [8]   cgs
Temperature 5170±60 [8]   K
Metallicity [Fe/H]0.1±0.2 [10]   dex
Rotational velocity (v sin i)0.9±0.5 [10]  km/s
Age 7.6+2.5
−3.3
[8]   Gyr
WASP-2B
Mass 0.40±0.02 [8]   M
Temperature 3523+28
−19
[8]   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 [11]
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. [11] The primary is a magnitude 12 orange dwarf star, orbited by a red dwarf star on a wide orbit. [7] [12] The star system shows an infrared excess noise of unknown origin. [13]

Contents

The primary star hosts one known exoplanet, WASP-2b. [14] Since the planet transits the star, the star is classified as a planetary transit variable and has received the variable star designation V357 Delphini. [6]

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. [15]

Planetary system

The primary star has one exoplanet, WASP-2b, a hot Jupiter detected by the SuperWASP project in 2006 using the transit method. [14]

The WASP-2 planetary system [10] [8]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 0.892±0.027  MJ 0.0308±0.00042.15222163(42)<0.01384.81+0.35
−0.27
°
1.060±0.024  RJ

See also

Notes

  1. The secondary star is identified with a "C" suffix so as to not confuse it with the planetary designation suffix "b". [1]

References

  1. 1 2 3 4 5 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.
  2. 1 2 3 4 5 6 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.
  3. Street, R. A.; Christian, D. J.; Clarkson, W. I.; Collier Cameron, A.; Enoch, B.; Kane, S. R.; Lister, T. A.; West, R. G.; Wilson, D. M.; Evans, A.; Fitzsimmons, A.; Haswell, C. A.; Hellier, C.; Hodgkin, S. T.; Horne, K.; Irwin, J.; Keenan, F. P.; Norton, A. J.; Osborne, J.; Pollacco, D. L.; Ryans, R.; Skillen, I.; Wheatley, P. J.; Barnes, J. (2007). "SuperWASP-N extrasolar planet candidates between 18 < RA < 21h". Monthly Notices of the Royal Astronomical Society. 379 (2): 816. arXiv: 0705.2598 . Bibcode:2007MNRAS.379..816S. doi: 10.1111/j.1365-2966.2007.11987.x .
  4. 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.
  5. 1 2 3 Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; Beichman, C. A.; Carpenter, J. M.; Chester, T.; Cambresy, L.; Evans, T.; Fowler, J.; Gizis, J.; Howard, E.; Huchra, J.; Jarrett, T.; Kopan, E. L.; Kirkpatrick, J. D.; Light, R. M.; Marsh, K. A.; McCallon, H.; Schneider, S.; Stiening, R.; Sykes, M.; Weinberg, M.; Wheaton, W. A.; Wheelock, S.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". Vizier Online Data Catalog. Bibcode:2003yCat.2246....0C.
  6. 1 2 "V357 Del". General Catalog of Variable Stars - VizieR . Retrieved 3 April 2025.
  7. 1 2 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.
  8. 1 2 3 4 5 6 7 8 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.
  9. 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.
  10. 1 2 3 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.
  11. 1 2 "WASP-2". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2009-05-04.
  12. Takeda, Yoichi (2005). "Precise Differential Analysis of Stellar Metallicities: Application to Solar Analogs Including 16 Cyg a and B". Publications of the Astronomical Society of Japan. 57: 83. Bibcode:2005PASJ...57...83T. doi:10.1093/pasj/57.1.83.
  13. 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.
  14. 1 2 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.
  15. 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.