WASP-12

WASP-12 is a magnitude 11 yellow dwarf star located approximately 1347 light-years away^[2] in the constellation Auriga.^[6] WASP-12 has a mass and radius similar to the Sun and is known for being orbited by a planet that is extremely hot and has a retrograde orbit around WASP-12. WASP-12 forms a triple star system with two red dwarf companions. Both of them have spectral types of M3V and are only 38% and 37% as massive as the Sun, respectively.^[5]

WASP-12

Artist's conception of WASP-12 & WASP-12b
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Auriga[1]
Right ascension	06h 30m 32.7966s[2]
Declination	+29° 40′ 20.264″[2]
Apparent magnitude (V)	11.560±0.068[3]
Characteristics
Spectral type	G0V[4] + M3V + M3V[5]
Apparent magnitude (B)	12.138±0.019[3]
Apparent magnitude (R)	~11.6[6]
Apparent magnitude (J)	10.477±0.021[7]
Apparent magnitude (H)	10.228±0.022[7]
Apparent magnitude (K)	10.188±0.020[7]
Astrometry
Radial velocity (Rv)	20.62±1.44[2] km/s
Proper motion (μ)	RA: −1.519(19) mas/yr[2] Dec.: −6.761(15) mas/yr[2]
Parallax (π)	2.4213±0.0166 mas[2]
Distance	1,347 ± 9 ly (413 ± 3 pc)
Details
A
Mass	1.325+0.026 −0.018[8] M☉
Radius	1.690+0.019 −0.018[8] R☉
Luminosity	4.05+0.54 −0.53[9] L☉
Surface gravity (log g)	4.11±0.11[8] cgs
Temperature	6265±50[8] K
Metallicity [Fe/H]	+0.12±0.07[8] dex
Rotational velocity (v sin i)	<1.9[8] km/s
Age	3.05±0.32[8] Gyr
Other designations
TOI-1725, TIC 86396382, WASP-12, TYC 1891-1178-1, 2MASS J06303279+2940202, UCAC2 42216354[6]
Database references
SIMBAD	A
	BC
Exoplanet Archive	data

Planetary system

In 2008, the exoplanet WASP-12b was discovered orbiting WASP-12 by SuperWASP, using the transit method. It is a hot Jupiter completing an orbit around its star in just one day.^[10] Its high carbon-to-oxygen ratio indicates that rocky planets might have formed in the star system, and it may be a carbon planet.^[11] It is subject to intensive photo-evaporation, and may be completely destroyed within one billion years from now.^[12]

In 2015, no indications of additional planets were found in the WASP-12 system.^[9]

The WASP-12 planetary system^[13]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	1.465±0.079 MJ	0.0232±0.00064	1.09142030(14)[9]	<0.02[14]	83.52±0.03°	1.937±0.056 RJ