Gamma Leonis b

Gamma¹ Leonis b

Exoplanet		List of exoplanets
Parent star
Star		Gamma Leonis
Constellation		Leo
Right ascension	(α)	10^h 19^m 58.3^s
Declination	(δ)	+19° 50′ 30″
Apparent magnitude	(mV)	2.28
Distance		125.5 ly (38.5 pc)
Spectral type		K0IIIb
Orbital elements
Semi-major axis	(a)	1.19[1] AU (178 Gm)
Periastron	(q)	1.02 AU (152 Gm)
Apastron	(Q)	1.36 AU (203 Gm)
Eccentricity	(e)	0.14[1]
Orbital period	(P)	429[1] d (1.17 y)
Orbital speed	(υ)	30.3 km/s
Physical characteristics
Minimum mass	(m sin i)	8.78[1] MJ
Discovery information
Discovery date		November 6, 2009
Discoverer(s)		Inwoo Han et al.[1]
Discovery method		Radial velocity
Discovery site		South Korea
Discovery status		Published

Gamma Leonis b is an extrasolar planet located 125.5 light years away in the constellation Leo, orbiting the giant star Gamma Leonis.^[1]

Discovery

On November 6, 2009, a planetary companion around primary star Gamma¹ Leonis has been announced.^[1] Moreover, radial velocity variations would also hint two strong signals at 8.5 and 1340 days. The former periodicity is likely due to stellar pulsation, whereas the latter could be indicative of the presence of an additional planetary companion with 2.14 Jupiter masses, moderate eccentricity (e=0.13) and located at 2.6 Astronomical Units away from the giant star. Nevertheless, the nature of such a signal is still unclear and further investigations are needed to confirm or rule out an additional substellar companion.

Characteristics

The planet has a minimum mass of 8.78 Jupiter masses. The true mass, as with the majority of other extrasolar planets discovered by the radial velocity method, is unknown.

References

1. Han, Inwoo; Lee, B. C.; Kim, K. M.; Mkrtichian, D. E.; Hatzes, A. P.; Valyavin, G. (2010). "Detection of a Planetary Companion around the giant star γ¹ Leonis". Astronomy and Astrophysics. 509. arXiv:0911.0968. Bibcode:2010A&A...509A..24H. doi:10.1051/0004-6361/200912536.

Coordinates: 10^h 19^m 58.3^s, +19° 50′ 30″