HAT-P-13

HAT-P-13, also known as GSC 03416-00543, is a G-type main sequence star approximately 800 light-years away in the constellation Ursa Major. In 2009 it was discovered that this star is orbited by two massive planets, the innermost of which transits the star. This was the first known example of an extrasolar transiting planet with an additional planet in the same system.^[3]

HAT-P-13

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Ursa Major[1]
Right ascension	08h 39m 31.8072s[2]
Declination	+47° 21′ 07.274″[2]
Apparent magnitude (V)	10.62
Characteristics
Spectral type	G4V[3]
Variable type	Planetary transit[3]
Astrometry
Radial velocity (Rv)	14.69 ± 0.68[3] km/s
Proper motion (μ)	RA: −24.060(16) mas/yr[2] Dec.: −26.218(17) mas/yr[2]
Parallax (π)	4.0750 ± 0.0186 mas[2]
Distance	800 ± 4 ly (245 ± 1 pc)
Details
Mass	1.261+0.029 −0.023[4] M☉
Radius	1.73+0.10 −0.09[4] R☉
Surface gravity (log g)	4.13 ± 0.04[5] cgs
Temperature	5720 ± 69[5] K
Metallicity [Fe/H]	0.46 ± 0.07[5] dex
Rotational velocity (v sin i)	3.1 ± 0.9[5] km/s
Age	5 Gyr
Other designations
TYC 3416-543-1, GSC 03416-00543, 2MASS J08393180+4721073[6]
Database references
SIMBAD	data
Exoplanet Archive	data

In 2015, a spectroscopic study have revealed a very strong starspot activity of the HAT-P-13 star.^[7]

Planetary system

As of 2009, HAT-P-13 has been confirmed to have two extrasolar planets orbiting it. The inner planet was discovered by the "transit method" and the outer planet was found through the radial velocity method. A search for transits by HAT-P-13c was negative, however only 72% of the possible transit configurations could be ruled out.^[8] HAT-P-13 was the first star to have a transiting planet and an additional planet on a known orbit.^[3] HAT-P-7 and other planets are known to have additional companions, but there is not enough data to characterize the system. OGLE-TR-111 has one confirmed transiting planet, and one unconfirmed transiting planet.

The innermost planet, HAT-P-13b, has a mass around that of Jupiter and orbits its sun roughly every three days. This classifies the planet as a hot Jupiter, with temperatures exceeding 1000 kelvins. The second companion, HAT-P-13c, has a mass over 15 Jupiters. Because of its mass, this companion could either be a massive planet or a low mass brown dwarf. Either way, HAT-P-13 c orbits its sun every 446 days in a highly eccentric orbit. Radial velocity measurements also suggest the existence of a third more distant companion in the system. This may be an additional planet, or it may be a brown dwarf or even a small star.^[9]

The HAT-P-13 planetary system^{[3][9][10][4]}

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	0.906±0.024 MJ	0.04313+0.00033 −0.00026	2.91624039±0.00000081	0.0093+0.0044 −0.0016	82.2+0.6 −0.8°	1.487±0.038 RJ
c	≥14.28 ± 0.28 MJ	1.188+0.018 −0.033	445.81±0.10	0.6616 ± 0.0054	—	—

See also

• HAT-P-12
• HATNet Project
• OGLE-TR-111

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. Bakos, G. Á.; et al. (2009). "HAT-P-13b,c: A Transiting Hot Jupiter with a Massive Outer Companion on an Eccentric Orbit". The Astrophysical Journal. 707 (1): 446–456. arXiv:0907.3525. Bibcode:2009ApJ...707..446B. doi:10.1088/0004-637X/707/1/446. S2CID 7591731.
4. Hardy, Ryan A.; et al. (2017). "Secondary Eclipses of HAT-P-13b". The Astrophysical Journal. 836 (1). 143. arXiv:1701.00828. Bibcode:2017ApJ...836..143H. doi:10.3847/1538-4357/836/1/143. S2CID 119488830.
5. Torres, Guillermo; et al. (2012). "Improved Spectroscopic Parameters for Transiting Planet Hosts". The Astrophysical Journal. 757 (2). 161. arXiv:1208.1268. Bibcode:2012ApJ...757..161T. doi:10.1088/0004-637X/757/2/161. S2CID 16580774.
6. "HAT-P-13". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2014-09-27.
7. 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
8. Szabó, Gy. M.; et al. (2010). "A multi-site campaign to detect the transit of the second planet in HAT-P-13". Astronomy and Astrophysics. 523. A84. arXiv:1009.3598. Bibcode:2010A&A...523A..84S. doi:10.1051/0004-6361/201015172. S2CID 118739793.
9. Winn, Joshua N.; et al. (2010). "The HAT-P-13 Exoplanetary System: Evidence for Spin-Orbit Alignment and a Third Companion". The Astrophysical Journal. 718 (1): 575–582. arXiv:1003.4512. Bibcode:2010ApJ...718..575W. doi:10.1088/0004-637X/718/1/575. S2CID 3836006.
10. Southworth, John; et al. (2012). "Refined physical properties of the HAT-P-13 planetary system". Monthly Notices of the Royal Astronomical Society. 420 (3): 2580–2587. arXiv:1111.5432. Bibcode:2012MNRAS.420.2580S. doi:10.1111/j.1365-2966.2011.20230.x. S2CID 56305549.