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.

HD 81040
Observation data
Epoch J2000      Equinox J2000
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 mas/yr[1]
Dec.: 35.708±0.036 mas/yr[1]
Parallax (π)29.0635 ± 0.0414 mas[1]
Distance112.2 ± 0.2 ly
(34.41 ± 0.05 pc)
Absolute magnitude (MV)5.12[4]
Details
Mass0.962±0.040[5] M
Radius0.91+0.01
−0.03
[6] R
Luminosity0.838±0.018[7] L
Surface gravity (log g)4.48[2] cgs
Temperature5,753[2] K
Metallicity [Fe/H]−0.06±0.03[4] dex
Rotation15.98 d[7]
Rotational velocity (v sin i)5.3[2] km/s
Age1.79+0.30
−0.26
[7] Gyr
Other designations
BD+20°2374, FK5 4836, GC 12951, HD 81040, HIP 46076, SAO 80800, PPM 99541[8]
Database references
SIMBADdata

Properties

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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

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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]

The HD 81040 planetary system[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

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References

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  1. ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c d e f g h 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. S2CID 119511744. 21.
  3. ^ a b 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. S2CID 52952408.
  4. ^ a b c 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. S2CID 119257644.
  5. ^ a b c Winn, Joshua N. (September 2022). "Joint Constraints on Exoplanetary Orbits from Gaia DR3 and Doppler Data". The Astronomical Journal. 164 (5): 196. arXiv:2209.05516. Bibcode:2022AJ....164..196W. doi:10.3847/1538-3881/ac9126. S2CID 252211643.
  6. ^ 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.
  7. ^ a b c d e Li, Yiting; Brandt, Timothy D.; Brandt, G. Mirek; Dupuy, Trent J.; Michalik, Daniel; Jensen-Clem, Rebecca; Zeng, Yunlin; Faherty, Jacqueline; Mitra, Elena L. (2021). "Precise Masses and Orbits for Nine Radial-velocity Exoplanets". The Astronomical Journal. 162 (6): 266. arXiv:2109.10422. Bibcode:2021AJ....162..266L. doi:10.3847/1538-3881/ac27ab. S2CID 237592581.
  8. ^ "HD 81040". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.
  9. ^ a b 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. S2CID 7647622.
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