WASP-12

WASP-12 is a magnitude 11 yellow dwarf star located approximately 1347 light-years away^[2] in the constellation Auriga.^[4] 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.^[7]

WASP-12

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 or F[citation needed]
Apparent magnitude (B)	12.138±0.019[3]
Apparent magnitude (R)	~11.6[4]
Apparent magnitude (J)	10.477±0.021[5]
Apparent magnitude (H)	10.228±0.022[5]
Apparent magnitude (K)	10.188±0.020[5]
Astrometry
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
Mass	1.434+0.11 −0.09[6] M☉
Radius	1.657+0.046 −0.044[6] R☉
Luminosity	4.05+0.54 −0.53[6] L☉
Temperature	6360+130 −140[6] K
Metallicity	+0.33+0.14 −0.17[6]
Other designations
TYC 1891-1178-1, 2MASS J06303279+2940202, UCAC2 42216354, Gaia DR2 3435282862461427072[4]
Database references
SIMBAD	data

Planetary system

In 2008, the extrasolar planet WASP-12b was discovered orbiting WASP-12 by the transit method.^[8] Its high carbon-to-oxygen ratio indicates that rocky planets might have formed in the star system, and it may be a carbon planet.^[9] It is subject to intensive photo-evaporation, and may be completely destroyed within one billion years from now.^[10]

In 2015, no indications of additional planets were found in the WASP-12 system except for WASP-12b.^[6]

• 
  WASP-12b.
• 
  WASP-12b.
• 
  Artist's conception of WASP-12 & WASP-12b

The WASP-12 planetary system

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	1.41±0.1 MJ	0.0229±0.0008	1.091423±0.000003	0.049±0.015	86.0±3.0[11]°	1.736±0.092[11] RJ

See also

• Lists of planets
• SuperWASP

References

1. 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. 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. 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. "SIMBAD query result: WASP-12 -- Star". Centre de Données astronomiques de Strasbourg. Retrieved 2009-04-24.
5. Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708. ISSN 0004-6256. S2CID 18913331. Vizier catalog entry
6. Collins, Karen A.; Kielkopf, John F.; Stassun, Keivan G. (2015). "TRANSIT TIMING VARIATION MEASUREMENTS OF WASP-12b AND QATAR-1b: NO EVIDENCE OF ADDITIONAL PLANETS". The Astronomical Journal. 153 (2): 78. arXiv:1512.00464. doi:10.3847/1538-3881/153/2/78. S2CID 55191644.
7. Bechter, Eric B.; Crepp, Justin R.; Ngo, Henry; Knutson, Heather A.; Batygin, Konstantin; Hinkley, Sasha; Muirhead, Philip S.; Johnson, John Asher; Howard, Andrew W.; Montet, Benjamin T.; Matthews, Christopher T.; Morton, Timothy D. (2014). "WASP-12b AND HAT-P-8b ARE MEMBERS OF TRIPLE STAR SYSTEMS". The Astrophysical Journal. 788 (1): 2. arXiv:1307.6857. Bibcode:2014ApJ...788....2B. doi:10.1088/0004-637X/788/1/2. S2CID 36306243.
8. Hebb, L.; et al. (2009-03-10). "WASP-12b: The Hottest Transiting Extrasolar Planet Yet Discovered". The Astrophysical Journal. 693 (2): 1920–1928. arXiv:0812.3240. Bibcode:2009ApJ...693.1920H. doi:10.1088/0004-637X/693/2/1920.
9. Madhusudhan, Nikku; Harrington, Joseph; Stevenson, Kevin B.; Nymeyer, Sarah; Campo, Christopher J.; Wheatley, Peter J.; Deming, Drake; Blecic, Jasmina; et al. (December 8, 2010). "A high C/O ratio and weak thermal inversion in the atmosphere of exoplanet WASP-12b". Nature. 469 (7328): 64–7. arXiv:1012.1603. Bibcode:2011Natur.469...64M. doi:10.1038/nature09602. PMID 21150901. S2CID 4415171..
10. D. Ehrenreich and J.-M. Désert, "Mass-loss rates for transiting exoplanets", 2011
11. Staff (2015). "Planet WASP-12 b". Extrasolar Planets Encyclopaedia. Retrieved 4 August 2017.

External links

• WASP-12b in transit (lightcurve)
• "WASP-12". Exoplanets. Archived from the original on 2009-11-25. Retrieved 2009-05-06.