HD 188015

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**HD 188015**
Observation data Equinox 2000
Constellation	Vulpecula
Right ascension	19^h 52^m 04.54^s
Declination	+28° 06' 1.36"
Apparent magnitude (V)	8.242
Absolute magnitude (V)	4.636
Distance	171.66 ly (52.63 pc)
Spectral type	G5IV
Other designations
BD+27°3539, HIP 97769

HD 188015 is an 8th magnitude star in the constellation of Vulpecula. It is a yellow subgiant, a Sun-like star that has ceased or is about to stop hydrogen fusion in its core. However, it is only slightly brighter than the Sun, but probably much older.

The star is almost twice as metal-rich as the Sun. Planets are common around such stars, and this star also has one known planet orbiting it.

[edit] HD 188015 b

**HD 188015 b**
Orbital elements

Semi-major axis a:	1.19 AU
Eccentricity e:	0.15 ± 0.09
Orbital period P:	456.46 d
Inclination i:	?°
Longitude of periastron ω:	293.0 ± 35.7°
Time of periastron τ:	2,451,883.51 ± 53.37 JD
Physical characteristics
Mass:	>1.26 M_J
Radius:	? R_J
Density:	? kg/m³
Temperature:	? K
Discovery
Discovery date:	2005
Detection method(s):
Discoverer(s):	Marcy, Butler, Vogt, et al.

The extrasolar planet, designated as HD 188015 b was announced by the California and Carnegie Planet Search team in 2005. Like majority of known planets, it was discovered using the radial velocity method.

The planet has a minimum mass about quarter greater than Jupiter. It orbits the star in a slightly eccentric orbit in a mean distance 20% further than Earth orbits the Sun.

What is interesting, is that the planet lies completely within the so-called "habitable zone", area where life as we know may flourish. The planet itself hardly can support life as it is certainly a surfaceless gas giant, but like Jupiter it may have massive moons. Unfortunately, the star is nearing the end of its life and will soon start to expand, becoming a red giant. If there is life inhabiting this system, it will likely be destroyed.