Astronomy:Tau1 Gruis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Grus |
| Right ascension | 22h 53m 37.932s[1] |
| Declination | –48° 35′ 53.83″[1] |
| Apparent magnitude (V) | +6.02[2] |
| Characteristics | |
| Spectral type | G0 V[3] |
| U−B color index | 0.17[2] |
| B−V color index | 0.62[2] |
| Variable type | None |
| Astrometry | |
| Radial velocity (Rv) | –1.1[4] km/s |
| Proper motion (μ) | RA: 217.04±0.37[1] mas/yr Dec.: −81.76±0.29[1] mas/yr |
| Parallax (π) | 30.66 ± 0.39[1] mas |
| Distance | 106 ± 1 ly (32.6 ± 0.4 pc) |
| Absolute magnitude (MV) | +3.46[5] |
| Details | |
| Mass | 1.28±0.04[6] M☉ |
| Radius | 1.71±0.04[6] R☉ |
| Luminosity | 3.39±0.02[6] L☉ |
| Surface gravity (log g) | 4.07±0.03[6] cgs |
| Temperature | 5,996±56[6] K |
| Metallicity [Fe/H] | 0.27±0.02[7] dex |
| Rotational velocity (v sin i) | 5.13[8] km/s |
| Age | 4.2±0.6[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
Tau1 Gruis, Latinized from τ1 Gruis, and catalogued as HD 216435 and HR 8700, is a yellow-hued star approximately 106 light-years away[1] in the constellation of Grus (the Crane). The star is visible to the naked eye for some people, placing it in the Bright Star Catalogue. In 2002, one extrasolar planet was confirmed to orbit the star.
Characteristics
Tau1 Gruis is a G-type main-sequence star of spectral type G0 V. It is estimated that the star has about 1.28 times the mass of the Sun, 1.71 times the Sun's radius, and about 3.6 times the luminosity. Due to its unusual brightness, at least one source suspects that the star may be a highly evolved subgiant star.[9] It is thought that Tau1 Gruis is about 1.4 times more enriched with elements heavier than hydrogen, making a high abundance of iron likely. The Ca-II H line of the star suggests that it is chromospherically inactive, making it significantly older than previously predicted.
Planetary system
On September 17, 2002, a team of astronomers led by Geoffrey Marcy announced the discovery of a giant planet around Tau1 Gruis.[9] The radial velocity measurements suggest that the star has a companion with at least 1.23 times the mass of Jupiter. The planet's orbit stays inside the system's habitable zone for most of its revolution around the star, though at apoapsis, the planet falls outside of this zone.[citation needed]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >1.26 ± 0.13 MJ | 2.56 ± 0.17 | 1311 ± 49 | 0.070 ± 0.078 | — | — |
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL.Vizier catalog entry
- ↑ 2.0 2.1 2.2 Corben, P. M. et al. (1972), "U, B, V photometry of 500 southern stars", Monthly Notes of the Astronomical Society of South Africa 31: 7–22, Bibcode: 1972MNSSA..31....8C.
- ↑ Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.
- ↑ Nordström, B. et al. (May 2014), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ~14000 F and G dwarfs", Astronomy and Astrophysics 418 (3): 989–1019, doi:10.1051/0004-6361:20035959, Bibcode: 2004A&A...418..989N.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 Bonfanti, A. et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics 575: A18. doi:10.1051/0004-6361/201424951. Bibcode: 2015A&A...575A..18B. http://www.aanda.org/articles/aa/full_html/2015/03/aa24951-14/aa24951-14.html.
- ↑ Tsantaki, M. et al. (July 2013), "Deriving precise parameters for cool solar-type stars. Optimizing the iron line list", Astronomy & Astrophysics 555: A150, doi:10.1051/0004-6361/201321103, Bibcode: 2013A&A...555A.150T.
- ↑ Delgado Mena, E. et al. (April 2015), "Li abundances in F stars: planets, rotation, and Galactic evolution", Astronomy & Astrophysics 576: 24, doi:10.1051/0004-6361/201425433, A69, Bibcode: 2015A&A...576A..69D.
- ↑ 9.0 9.1 Jones, R. Paul et al. (2003). "An exoplanet in orbit around τ1 Gruis". Monthly Notices of the Royal Astronomical Society 341 (3): 948–952. doi:10.1046/j.1365-8711.2003.06481.x. Bibcode: 2003MNRAS.341..948J. http://mnras.oxfordjournals.org/content/341/3/948.full.
- ↑ Butler, R. P. et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal 646 (1): 505–522. doi:10.1086/504701. Bibcode: 2006ApJ...646..505B.
External links
- "Notes for star HD 216435". Extrasolar Planets Encyclopaedia. http://exoplanet.eu/star.php?st=HD+216435. Retrieved 2008-06-22.
- "Tau1 Gruis". Solstation. http://www.solstation.com/stars2/tau1gru.htm. Retrieved 2008-06-22.
Coordinates: 
22h 53m 37.9315s, −48° 35′ 53.828″
 |  |
