Astronomy:HD 81040
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Leo |
| Right ascension | 09h 23m 47.08737s[1] |
| Declination | +20° 21′ 52.0349″[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: −151.265±0.045[1] mas/yr Dec.: 35.708±0.036[1] mas/yr |
| Parallax (π) | 29.0635 ± 0.0414[1] mas |
| Distance | 112.2 ± 0.2 ly (34.41 ± 0.05 pc) |
| Absolute magnitude (MV) | 5.12[4] |
| Details | |
| Mass | 0.962±0.040[5] M☉ |
| Radius | 0.91+0.01 −0.03[6] R☉ |
| Luminosity | 0.838±0.018[7] L☉ |
| Surface gravity (log g) | 4.48[2] cgs |
| Temperature | 5,753[2] K |
| Metallicity [Fe/H] | −0.06±0.03[4] dex |
| Rotation | 15.98 d[7] |
| Rotational velocity (v sin i) | 5.3[2] km/s |
| Age | 1.79+0.30 −0.26[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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.
Properties
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.[9] Later measurements by modelling chromosperic activity suggested an age of 4.18 Gyr.[citation needed]
Planetary system
On November 24, 2005, a superjovian planet was announced by Sozzetti et al.[9] It was discovered using the radial velocity method. Astrometric measurements using Gaia, published in several papers, show that the inclination of its orbit is about 111 degrees, so its true mass is somewhat higher than that predicted from its minimum mass.[7][5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 7.53±0.032 MJ | 1.946±0.014 | 1,004.7±3.0 | 0.525+0.024 −0.026 |
111.4+4.4 −4.7° |
— |
See also
- List of extrasolar planets
- List of stars in Leo
References
- ↑ 1.0 1.1 1.2 1.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal 153 (1): 19. doi:10.3847/1538-3881/153/1/21. 21. Bibcode: 2017AJ....153...21L.
- ↑ 3.0 3.1 Soubiran, C. et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics 616: A7. doi:10.1051/0004-6361/201832795. Bibcode: 2018A&A...616A...7S.
- ↑ 4.0 4.1 4.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 5.0 5.1 5.2 Winn, Joshua N. (September 2022). "Joint Constraints on Exoplanetary Orbits from Gaia DR3 and Doppler Data". The Astronomical Journal 164 (5): 196. doi:10.3847/1538-3881/ac9126. Bibcode: 2022AJ....164..196W.
- ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 7.0 7.1 7.2 7.3 7.4 Li, Yiting; Brandt, Timothy D.; Brandt, G. Mirek; Dupuy, Trent J.; Michalik, Daniel; Jensen-Clem, Rebecca; Zeng, Yunlin; Faherty, Jacqueline et al. (2021). "Precise Masses and Orbits for Nine Radial-velocity Exoplanets". The Astronomical Journal 162 (6): 266. doi:10.3847/1538-3881/ac27ab. Bibcode: 2021AJ....162..266L.
- ↑ "HD 81040". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+81040.
- ↑ 9.0 9.1 Sozzetti, A. et al. (2006). "A massive planet to the young disc star HD 81040". Astronomy and Astrophysics 449 (1): 417–424. doi:10.1051/0004-6361:20054303. Bibcode: 2006A&A...449..417S. http://www.aanda.org/articles/aa/full/2006/13/aa4303-05/aa4303-05.html.
External links
Coordinates: 
09h 23m 47.0873s, +20° 21′ 52.034″
 |  |
