HD 81040
HD 81040 is a star in the equatorial constellation of Leo. With an apparent visual magnitude of +7.73[2] it is too dim to be visible to the naked eye but can be viewed with a small telescope. The star is located at a distance of 112 light years from the Sun based on parallax. It is drifting further away with a radial velocity of +49 km/s,[3] having come to within 48 light-years some 527,000 years ago.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Leo |
| Right ascension | 09h 23m 47.08736s[1] |
| Declination | +20° 21′ 52.0282″[1] |
| Apparent magnitude (V) | +7.73[2] |
| Characteristics | |
| Spectral type | G0V[2] |
| B−V color index | 0.680±0.012 |
| Astrometry | |
| Radial velocity (Rv) | +49.270±0.0017[3] km/s |
| Proper motion (μ) | RA: −151.258±0.093[1] mas/yr Dec.: +36.125±0.065[1] mas/yr |
| Parallax (π) | 29.0122 ± 0.0649[1] mas |
| Distance | 112.4 ± 0.3 ly (34.47 ± 0.08 pc) |
| Absolute magnitude (MV) | 5.12[4] |
| Details[2] | |
| Mass | 0.87 M☉ |
| Radius | 0.91+0.01 −0.03[1] R☉ |
| Luminosity | 0.76 L☉ |
| Surface gravity (log g) | 4.48 cgs |
| Temperature | 5,753 K |
| Metallicity [Fe/H] | −0.06±0.03[4] dex |
| Rotational velocity (v sin i) | 5.3 km/s |
| Age | 8.68 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinary G-type main-sequence star with a stellar classification of G0V.[2] The Sun somewhat dwarfs HD 81040 in terms of physical characteristics: it has 87% of the Sun's mass and 91% of the radius of the Sun. It is spinning with a projected rotational velocity of 5.3 km/s,[2] and has near solar metallicity.[4] The age of the star is not precisely known; the ELODIE spectrograph suggested 0.8 Gyr and found it to have a young dust disk.[6] Later measurements by modelling chromosperic activity suggested an age of 4.18 Gyr.
== Planetary system == On November 24, 2005, a superjovian planet was announced by Sozzetti.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥6.86±0.71 MJ | 1.94 | 1,001.7±7.0 | 0.526±0.042 | — | — |
See also
- List of extrasolar planets
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. 21.
- Soubiran, C.; et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics. 616: A7. arXiv:1804.09370. Bibcode:2018A&A...616A...7S. doi:10.1051/0004-6361/201832795.
- Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
- "HD 81040". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.
- Sozzetti, A.; et al. (2006). "A massive planet to the young disc star HD 81040". Astronomy and Astrophysics. 449 (1): 417–424. arXiv:astro-ph/0511679. Bibcode:2006A&A...449..417S. doi:10.1051/0004-6361:20054303.
