WASP-3

WASP-3 is a triple star system located about 753 light-years (231 parsecs) away from the Sun in the constellation Lyra. The system has an apparent magnitude of 10. The brightest and most massive star of this system is WASP-3A, an F-type main sequence star which has one known transiting hot Jupiter exoplanet, WASP-3b. Since the planet transits the star, the star is classified as a planetary transit variable and has received the variable star designation V838 Lyrae.^[7]

WASP-3

A light curve for WASP-3, plotted from TESS data[1]
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Lyra[2]
WASP-3A
Right ascension	18h 34m 31.6252s[3]
Declination	+35° 39′ 41.492″[3]
Apparent magnitude (V)	10.63±0.05[4]
WASP-3C
Right ascension	18h 34m 30.2553s[5][6]
Declination	+35° 39′ 34.004″[5][6]
Characteristics
WASP-3A
Evolutionary stage	main-sequence star
Spectral type	F7V[4]
Apparent magnitude (B)	11.07±0.06[4]
Apparent magnitude (G)	10.4541±0.0028[4][6]
Apparent magnitude (J)	9.603±0.020[4]
Apparent magnitude (H)	9.407±0.014[4]
Apparent magnitude (K)	9.361±0.015[4]
Variable type	planetary transit[7]
WASP-3B
Apparent magnitude (J)	16.88±0.12[8]
Apparent magnitude (H)	16.090±0.079[8]
Apparent magnitude (K)	16.002±0.052[8]
Astrometry
WASP-3A
Radial velocity (Rv)	−5.490±0.007[9] km/s
Proper motion (μ)	RA: −5.791(12) mas/yr[3] Dec.: −21.929(15) mas/yr[3]
Parallax (π)	4.3338±0.0120 mas[3]
Distance	753 ± 2 ly (230.7 ± 0.6 pc)
Details
WASP-3A
Mass	1.24+0.06 −0.11[9]: 1581  M☉
Radius	1.366±0.044[10] R☉
Surface gravity (log g)	4.30+0.07 −0.03[9]: 1581  cgs
Temperature	6400±100[9]: 1581  K
Metallicity	0.00±0.20[9]: 1581
Rotational velocity (v sin i)	13.4±1.5[10] km/s
Age	2.1±1.2[10] Gyr
WASP-3B
Mass	0.108±0.006[8]: 14  M☉
Surface gravity (log g)	~5.22[8]: 13  cgs
Temperature	~2900[8]: 13  K
Position (relative to WASP-3A)[8]: 11, 14
Component	WASP-3B
Epoch of observation	2012–2013
Angular distance	~1.19″
Position angle	~87.1°
Projected separation	300±20 AU
Position (relative to WASP-3A)[6]
Component	WASP-3C
Angular distance	18.33192±0.00002″
Position angle	245.81872±0.00006°
Projected separation	4230 AU
Other designations
V838 Lyr, BD+35 3293, TOI-2131, TIC 27848472, WASP-3, TYC 2636-195-1, GSC 02636-00195, 2MASS J18343163+3539415, USNO-B1.0 1256-00285133, 1SWASP J183431.62+353941.4[4]
Database references
SIMBAD	data
Exoplanet Archive	data

Triple system

WASP-3 has been identified as a triple star system in a 2019 study of astrometry from the Gaia mission.^[11]: 5093 The brightest and most massive component of the system is WASP-3A, an F-type main sequence star that is 1.24 times as massive as the Sun and 1.31 times as large as the Sun in radius.^[9]: 1581 WASP-3A appears to be a variable star; observations between 2007 and 2010 show that the star's chromospheric activity had increased during that time period.^[12] The second companion, WASP-3B, is a low-mass star about 0.11 times as massive as the Sun and has an effective temperature of about 2900 K.^{[8]: 11, 13} WASP-3B is separated eastward from WASP-3A at an angular separation of approximately 1.19 arcseconds, corresponding to a projected separation distance of about 300 AU.^{[8]: 11, 13} WASP-3B was first identified in observations from 2012 to 2013.^[8]: 14 The third companion, WASP-3C, is much more distant with an angular separation of approximately 18.3 arcseconds from WASP-3A, corresponding to a projected separation distance of 4230 AU.^[11]: 5093 WASP-3C is about 0.77 times as massive as the Sun and has an effective temperature of about 4700 K.^[6]

Planetary system

WASP-3A has one known transiting hot Jupiter extrasolar planet, WASP-3b, which was detected by the SuperWASP project in 2007.^[9] It was confirmed in 2008 by observations from the William Herschel Telescope.

In 2010, researchers proposed a second planet orbiting WASP-3A due to transit timing variations in WASP-3b.^[13][14] But in 2012 this proposal was refuted.^[12]

The WASP-3 planetary system^[10]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	1.89±0.12 MJ	0.03182+0.00080 −0.00085	1.8468351(4)	<0.0058	83.72±0.39°	1.416±0.047 RJ

See also

• SuperWASP
• WASP-4