HD 99109

From Wikipedia, the free encyclopedia

**HD 99109**
Observation data Epoch J2000.0
Constellation (pronunciation)	Leo
Right ascension	11^h 24^m 17.358^s
Declination	-01° 31′ 44.674″
Apparent magnitude (V)	+9.10
Characteristics
Spectral type	K0V
U-B color index	?
B-V color index	+0.87
Variable type	suspected
Astrometry
Radial velocity (R_v)	? km/s
Proper motion (μ)	RA: -179.71 mas/yr Dec.: -160.61 mas/yr
Parallax (π)	16.54 ± 1.31 mas
Distance	197.19 ± 15.7 ly (60.46 ± 4.8 pc)
Absolute magnitude (M_V)	+5.19
Details
Mass	0.93 M_☉
Radius	? R_☉
Luminosity	0.724 L_☉
Temperature	5272 K
Metallicity	2.07 × Sun
Rotation	?
Age	>12.2 years
Other designations
BD-00º2437, HIP 55664, SAO 138182

HD 99109 is a K-type main-sequence star in the constellation Leo. It is one and half degree away from the celestial equator to the south. It is an orange dwarf, meaning that it is 93% as massive, probably smaller, and 72.4% the luminosity of our Sun. It is over twice the abundance of iron relative to hydrogen than the Sun in which the planets are common around such stars. There is one known planet in this star system found in 2006.

[edit] HD 99109 b

**HD 99109 b**
Orbital elements

Semi-major axis a:	1.105 ± 0.065 AU
Eccentricity e:	0.09 ± 0.16
Orbital period P:	439.3 ± 5.6 d
Inclination i:	?°
Angular distance θ:	18.264 mas
Longitude of periastron ω:	256°
Time of periastron τ:	2,411,310 ± 80 JD
Semi-amplitude K:	14.1 ± 2.2 m/s
Physical characteristics
Mass:	>0.502 ± 0.07 M_J
Radius:	? R_J
Density:	? kg/m³
Gravity:	? g
Temperature:	~225 K
Discovery
Discovery date:	July 15, 2006
Discovery site:
Detection method(s):	Radial velocity
Discoverer(s):	Butler et al.
Other catalogue

HD 99109 b is a W-type planet one half the mass of Jupiter and orbits slightly further from the star than Earth to the Sun. The orbital eccentricity is about the same as planet Mars.