HAT-P-9b

HAT-P-9b

Extrasolar planet		List of extrasolar planets
Size comparison of HAT-P-9b with Jupiter.
Parent star
Star		HAT-P-9
Constellation		Auriga
Right ascension	(α)	07h 20m 40.479s
Declination	(δ)	+37° 08′ 26.17″
Distance		1560 ± 190 ly (480 ± 60 pc)
Spectral type		F
Orbital elements
Semimajor axis	(a)	0.0528 ± 0.002 AU
Periastron	(q)	0.0527 AU
Apastron	(Q)	0.0529 AU
Eccentricity	(e)	~0.0012
Orbital period	(P)	3.92289 ± 0.00004 d (0.0107401 y)
Time of transit	(Tt)	2454417.9077 ± 0.0003 JD
Physical characteristics
Mass	(m)	0.78 ± 0.09 MJ (250 M⊕)
Radius	(r)	1.4 ± 0.06 RJ (15 R⊕) (96 Mm)
Density	(ρ)	380 kg m-3
Surface gravity	(g)	10.3 m/s² (1.05 g)
Discovery information
Discovery date		June 26, 2008
Discoverer(s)		Shporer et al.
Detection method		Transit (SuperWASP)
Discovery site		Cambridge, Massachusetts
Discovery status		Published
Database references
Extrasolar Planets Encyclopaedia		data
SIMBAD		data

HAT-P-9b is an extrasolar planet approximately 1560 light years away in the constellation Auriga. This planet was found by the transit method on June 26, 2008. It has mass 78% that of Jupiter and radius 140% that of Jupiter. As for all the transiting planets excluding HD 17156 b, this planet is so-called hot Jupiter, meaning this Jupiter-like planet orbits extremely close to the parent star, taking only 3.92 days to orbit at the average distance of 7.9 gigameters.

References

• Shporer, A.; Bakos, G. A.; Bouchy, F.; Pont, F.; Kovacs, G.; Latham, D. W.; Sipocz, B.; Torres, G.; Mazeh, T.; Esquerdo, G. A.; Pal, A.; Noyes, R. W.; Sasselov, D. D.; Lazar, J.; Papp, I.; Sari, P.; Kovacs, G. (June 2008). "HAT-P-9b: A Low Density Planet Transiting a Moderately Faint F star". ARXIV 690 (2): 1393. arXiv:0806.4008. Bibcode 2009ApJ...690.1393S. doi:10.1088/0004-637X/690/2/1393. 

External links

Media related to HAT-P-9b at Wikimedia Commons