Gliese 229

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Gliese 229
Observation data
Epoch J2000.0
Constellation
(pronunciation)		 Lepus
Right ascension 06h 10m 35s
Declination -21° 51′ 42″
Apparent magnitude (V) 8.18
Characteristics
Spectral type M1V
B-V color index 1.51
Variable type Flare star
Astrometry
Distance 19 ly (6.3 pc)
Details
Radius 0.6 R☉
Temperature 3720 K
Age 3 billion years
Other designations
BD-21°1377, HD 42581, HIP 29295, LHS 1827, NSV 2863, SAO 171334, TYC 5945- 765-1
Database references
SIMBAD data

Gliese 229, often abbreviated as Gl 229 or GJ 229, is a red dwarf star approximately 19 light-years away in the constellation of Lepus (the Hare). The star is known to be a flare star. As of 1994, a substellar companion was imaged and in 1995 it was confirmed via Doppler Spectroscopy.

[edit] Star system

The primary star within the system is Gliese 229 A. This cool red dwarf star is calculated to have about 56 percent the mass of the Sun, less then 53 percent of its radius, and 1.6 percent of its luminosity. The star is a confirmed flare star approximately 3 billion years old.

The confirmation image of Gliese 229 B.
The confirmation image of Gliese 229 B.

Discovered in 1994, Gliese 229 B (often classified as Gliese 229 b) was the first Substellar Mass Object to be unquestionably identified. This brown dwarf has around 25 to 65 times the mass of Jupiter, and about 0.9 to 1.1 times the radius. With a surface temperature of around 1000 to 1200 degrees Celsius, the brown dwarf is thought to be like Jupiter (with an abundance of methane within the planet).

Under one proposed classification scheme, Gliese 229 B has been given a spectral type of T6.5V. It is currently calculated that Gliese 229 B orbits the primary star at a separation of 39 astronomical units (approximately the same distance as Pluto is from the Sun).

[edit] External links


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