WASP-4 (original) (raw)

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G-type main sequence star in the constellation Phoenix

WASP-4

Artistic rendering of WASP-4 b
Observation dataEpoch J2000.0 Equinox J2000.0
Constellation Phoenix[1]
Right ascension 23h 34m 15.0857s[2]
Declination −42° 03′ 41.048″[2]
Apparent magnitude (V) 12.468±0.025[3]
Characteristics
Evolutionary stage Main sequence
Spectral type G7V[4]
Apparent magnitude (V) 12.468±0.025[3]
Apparent magnitude (B) 13.216±0.020[3]
Variable type Planetary transit variable[4]
Astrometry
Radial velocity (Rv) 57.61±0.76[2] km/s
Proper motion (μ) RA: 9.950(12) mas/yr[2] Dec.: −87.620(10) mas/yr[2]
Parallax (π) 3.6623 ± 0.0147 mas[2]
Distance 891 ± 4 ly (273 ± 1 pc)
Details[5]
Mass 0.89±0.01 M☉
Radius 0.920±0.060 R☉
Surface gravity (log g) 4.484+0.037−0.047[6] cgs
Temperature 5436±34 K
Metallicity [Fe/H] −0.050±0.040 dex
Rotation 22.2±3.3 d
Rotational velocity (v sin i) 2.2+0.6−1.0 km/s
Age 7.0±2.9 Gyr
Other designations
1SWASP J233415.06-420341.1, TOI-232, TIC 402026209, WASP-4, TYC 8017-108-1, 2MASS J23341508-4203411[7]
Database references
SIMBAD data

WASP-4 is a G-type main-sequence star approximately 891 light-years away in the constellation of Phoenix.[4][1][2] Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by a giant planet on a close orbit.[8]

In 2007 the exoplanet WASP-4b was discovered orbiting this star. With an orbital period of just 1.3 days it is classified as a hot Jupiter.[4] The planet's orbital period appears to be decreasing at a rate of 7.33±0.71 milliseconds per year, suggesting that its orbit is decaying, with a decay timescale of 15.77±1.57 million years. Another superjovian planet in the system is suspected.[9]

The WASP-4 planetary system[9]

Companion(in order from star) Mass Semimajor axis(AU) Orbital period(days) Eccentricity Inclination Radius
b 1.164±0.082 MJ 0.02239±0.00084 1.338231587(22) <0.0033[5] 88.02±0.69° 1.312±0.045 RJ
c (unconfirmed) ≥5.47±0.44 _M_J 6.82±0.25 7001.0±6.6 — — —
  1. ^ a b Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Vizier query form
  2. ^ a b c d e f 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. ^ a b c Henden, A. A.; et al. (2016). "VizieR Online Data Catalog: AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)". VizieR On-line Data Catalog: II/336. Originally Published in: 2015AAS...22533616H. 2336. Bibcode:2016yCat.2336....0H. Vizier catalog entry
  4. ^ a b c d Wilson, D. M.; et al. (2008). "WASP-4b: A 12th Magnitude Transiting Hot Jupiter in the Southern Hemisphere". The Astrophysical Journal Letters. 675 (2): L113–L116. arXiv:0801.1509. Bibcode:2008ApJ...675L.113W. doi:10.1086/586735. S2CID 10823235.
  5. ^ a b 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.
  6. ^ Dragomir, Diana; Kane, Stephen R.; Pilyavsky, Genady; Mahadevan, Suvrath; Ciardi, David R.; Zachary Gazak, J.; Gelino, Dawn M.; Payne, Alan; Rabus, Markus; Ramirez, Solange V.; von Braun, Kaspar; Wright, Jason T.; Wyatt, Pamela (2011). "Terms Photometry of Known Transiting Exoplanets". The Astronomical Journal. 142 (4): 115. arXiv:1108.2308. Bibcode:2011AJ....142..115D. doi:10.1088/0004-6256/142/4/115. S2CID 118606598.
  7. ^ "WASP-4". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-09-22.
  8. ^ Maxted, P. F. L.; Serenelli, A. M.; Southworth, J. (2015), "A comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars", Astronomy & Astrophysics, 577: A90, arXiv:1503.09111, Bibcode:2015A&A...577A..90M, doi:10.1051/0004-6361/201525774, S2CID 53324330
  9. ^ a b Turner, Jake D.; Flagg, Laura; Ridden-Harper, Andrew; Jayawardhana, Ray (2022), "Characterizing the WASP-4 System with TESS and Radial Velocity Data: Constraints on the Cause of the Hot Jupiter's Changing Orbit and Evidence of an Outer Planet", The Astronomical Journal, 163 (6): 281, arXiv:2112.09621, Bibcode:2022AJ....163..281T, doi:10.3847/1538-3881/ac686f, S2CID 245329747