GJ 3021
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| Observation data Epoch J2000 |
|
|---|---|
| Constellation (pronunciation) |
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
|
|
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 8.8 billion 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 | List of extrasolar planets | |
|---|---|---|
| Orbital elements | ||
| Semimajor axis | (a) | 0.495[3] AU |
| Eccentricity | (e) | 0.511 ± 0.017[3] |
| Orbital period | (P) | 133.71 ± 0.20[3] d |
| Angular distance | (θ) | 27.809 mas |
| Longitude of periastron |
(ω) | 290.7 ± 3.0[3]° |
| Time of periastron | (T0) | 2,451,545.86 ± 0.64[3] JD |
| Semi-amplitude | (K) | 167.0 ± 4.0[3] m/s |
| Physical characteristics | ||
| Mass | (m) | >3.37[3] MJ |
| Discovery information | ||
| Discovery date | 2000 | |
| Discoverer(s) | Naef et al. | |
| Detection method | Radial velocity | |
| Discovery site | CORALIE | |
| Discovery status | Published | |
GJ 3021 b is a jovian planet orbiting about 0.5 AU from its star with a minimum mass 3.37 times that of Jupiter, as determined by measuring variations in the radial velocity of the star. A study published in 2001 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.[4] 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. However later analysis showed that Hipparcos was not sensitive enough to accurately determine astrometric orbits for substellar companions, which means the inclination (and hence the true mass) of the planet are still unknown.[5]
[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. doi:.
- ^ a b c d e f g Butler, R. P. et al. (2007). Catalog of Nearby Exoplanets. Retrieved on 2007-07-28.
- ^ Han et al. (2001). "Preliminary astrometric masses for proposed extrasolar planetary companions". The Astrophysical Journal 548 (1): L57 – L60. doi:.
- ^ Pourbaix, D. and Arenou, F. (2001). "Screening the Hipparcos-based astrometric orbits of sub-stellar objects". Astronomy and Astrophysics 372: 935 – 944. doi:.
[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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