Gliese 229
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| 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 | |
| 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.
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
- Astronomers Announce First Clear Evidence of a Brown Dwarf – STScI news release STScI-1995-48 (November 29, 1995)
- Brown dwarfs (NASA)
- Gliese 229. Extrasoalr Visions. Retrieved on 2008-06-12.
- Gliese 229 B. Extrasoalr Visions. Retrieved on 2008-06-12.
- Gliese 229. SolStation. Retrieved on 2008-06-12.
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