GJ 3021
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| Observation data Epoch J2000 |
|
|---|---|
| Constellation | Hydrus |
| Right ascension | 00h 16m 12.6775s |
| Declination | -79° 51' 04.254" |
| Apparent magnitude (V) | 6.59 |
| Distance | 57.47 ly (17.62 pc) |
| Spectral type | G6V |
| Other designations | |
|
HD 1237, HIP 1292
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|
GJ 3021 is a 6th magnitude star in the constellation Hydrus. It is of note for being a relatively sun-like star not very far from the Sun that is home to an extrasolar planet[1].
As a nearby sun-like star, the last decade has seen GJ 3021 being studied carefully for the first time, especially after its substellar companion was discovered. It is currently believed that it is 600 million years old[citation needed], though age estimates range from 150 million to 8,800 million years old depending on the method used for the determination[2]. The star is more enriched with iron than the Sun, is chromospherically active, and rotates around its axis more quickly than the Sun.
Contents |
[edit] GJ 3021 b
| Extrasolar planet | Lists of extrasolar planets | |
|---|---|---|
| Orbital elements | ||
| Semimajor axis | (a) | 0.49 AU |
| Eccentricity | (e) | 0.505 ± 0.018 |
| Orbital period | (P) | 133.82 ± 0.2 d |
| Inclination | (i) | ?° |
| Longitude of periastron |
(ω) | 291° |
| Time of periastron | (τ) | 1412.48 JD |
| Physical characteristics | ||
| Mass | (m) | >3.32 MJ |
| Radius | (r) | ? RJ |
| Density | (ρ) | ? kg/m3 |
| Temperature | (T) | ? K |
| Discovery information | ||
| Discovery date | 2000 | |
| Discoverer(s) | Naef et al. | |
| Detection method | Radial velocity | |
| Discovery status | Confirmed | |
GJ 3021 b is a jovian planet or small brown dwarf orbiting about 0.5 AU from its star. When first discovered, it was announced as having a mass of no less than 3.45 times that of Jupiter[citation needed], a lower limit that was subsequently amended to 3.32. A further study of the matter[3] suggested that the usual inability to determine the orbital inclination of an extrasolar planet through radial velocity measurement had caused this mass to be severely underestimated. The astrometric orbit gives an orbital inclination of 11.8° and a mass of 16 Jupiter masses, which would make the object a brown dwarf.
[edit] See also
[edit] References
- ^ *Naef et al. (2001). "The CORALIE survey for southern extrasolar planets V. 3 new extrasolar planets". Astronomy and Astrophysics 375: 205-218.
- ^ Saffe, C. et al. (2005). "On the Ages of Exoplanet Host Stars". Astronomy and Astrophysics 443 (2): 609 – 626.
- ^ I. Han, D.C. Black, G. Gatewood (2001). "Preliminary astrometric masses for proposed extrasolar planetary companions". Astrophysical Journal 548: L57 – L60.
[edit] External links
- HD 1237. SIMBAD. Retrieved on 17 April 2006.
- Notes for star GJ 3021. The Extrasolar Planets Encyclopaedia. Retrieved on 17 April 2006.
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