HD 188015

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**HD 188015**
Observation data Epoch 2000
Constellation (pronunciation)	Vulpecula
Right ascension	19^h 52^m 04.54^s
Declination	+28° 06' 1.36"
Apparent magnitude (V)	8.242
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**
Discovery
Discovered by	Marcy et al.
Discovery site	USA
Discovery date	2005
Detection method	Radial velocity
Orbital characteristics
Semi-major axis	1.203 ± 0.070 AU
Eccentricity	0.137 ± 0.026
Orbital period	461.2 ± 1.7 d
Angular distance	23 mas
Longitude of periastron	222° ± 10°
Time of periastron	2,451,787 ± 17 JD
Semi-amplitude	37.6 ± 1.2 m/s
Physical characteristics
Mass	>1.50 ± 0.13 M_J

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.