HD 194012

HD 194012 (HR 7793; Gliese 789) is a star in the equatorial constellation Delphinus. It has an apparent magnitude of 6.15,^[2] making it visible to the naked eye under ideal conditions. The star is relatively close at a distance of only 85 light years^[1] but is receding with a heliocentric radial velocity of 4.5 km/s.^[5]

HD 194012

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Delphinus
Right ascension	20h 22m 52.3692s[1]
Declination	+14° 33′ 03.9513″[1]
Apparent magnitude (V)	6.15±0.01[2]
Characteristics
Spectral type	F7 V[3]
U−B color index	−0.07[4]
B−V color index	+0.51[4]
Astrometry
Radial velocity (Rv)	4.5±0.2[5] km/s
Proper motion (μ)	RA: +78.997 mas/yr[1] Dec.: −7.143 mas/yr[1]
Parallax (π)	38.4009 ± 0.0233 mas[1]
Distance	84.93 ± 0.05 ly (26.04 ± 0.02 pc)
Absolute magnitude (MV)	+4.06[6]
Details
Mass	1.21+0.19 −0.16[7] M☉
Radius	1.18±0.04[7] R☉
Luminosity	1.9[8] L☉
Surface gravity (log g)	4.36[8] cgs
Temperature	6,301±80[9] K
Metallicity [Fe/H]	−0.06[8] dex
Rotational velocity (v sin i)	5[10] km/s
Age	1.06[11] Gyr
Other designations
AG+14°2196, BD+14°4275, GC 28343, GJ 789, HD 194012, HIP 100511, HR 7793, SAO 106042[12]
Database references
SIMBAD	data

HD 194012 has a stellar classification of F7 V,^[3] indicating that it is an ordinary F-type main-sequence star. It has 121% the mass of the Sun^[7] and is estimated to be a billion years old,^[11] spinning with a projected rotational velocity of 5 km/s.^[10] The star's diameter is 118% that of the Sun^[7] and shines with a luminosity of 1.9 L_☉^[8] from its photosphere at an effective temperature of 6,301 K,^[9] giving a yellow white hue. HD 194012's metallicity is calculated to be 87% that of the Sun.^[8]

A 2010 paper has identified a candidate substellar companion 12.78″ away along a position angle of 67.9°.^[13] HD 194012 has been examined for infrared excess suggesting a debris disk but none was found.^[14]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
3. Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Robinson, P. E. (October 2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I." The Astronomical Journal. 126 (4): 2048–2059. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365. eISSN 1538-3881. ISSN 0004-6256.
4. Marlborough, J. M. (March 1964). "Frequency of ultraviolet excess among late-type dwarfs in the solar neighbourhood". The Astronomical Journal. 69: 215. Bibcode:1964AJ.....69..215M. doi:10.1086/109258. ISSN 0004-6256.
5. Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. ISSN 1063-7737. S2CID 119231169.
6. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 119257644.
7. Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
8. Luck, R. Earle (21 December 2016). "Abundances in the Local Region. II. F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 21. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. eISSN 1538-3881.
9. Casagrande, L.; Schönrich, R.; Asplund, M.; Cassisi, S.; Ramírez, I.; Meléndez, J.; Bensby, T.; Feltzing, S. (June 2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s): Improved astrophysical parameters for the Geneva-Copenhagen Survey⋆". Astronomy & Astrophysics. 530: A138. arXiv:1103.4651. Bibcode:2011A&A...530A.138C. doi:10.1051/0004-6361/201016276. ISSN 0004-6361.
10. Kraft, Robert P. (November 1967). "Studies of Stellar Rotation. V. The Dependence of Rotation on Age among Solar-Type Stars". The Astrophysical Journal. 150: 551. Bibcode:1967ApJ...150..551K. doi:10.1086/149359. eISSN 1538-4357. ISSN 0004-637X.
11. Demarque, Pierre; Woo, Jong‐Hak; Kim, Yong‐Cheol; Yi, Sukyoung K. (December 2004). "Y 2 Isochrones with an Improved Core Overshoot Treatment". The Astrophysical Journal Supplement Series. 155 (2): 667–674. arXiv:astro-ph/0409024. Bibcode:2004ApJS..155..667D. doi:10.1086/424966. ISSN 1538-4357.
12. "HD 194012". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved June 16, 2022.
13. Tanner, Angelle M.; Gelino, Christopher R.; Law, Nicholas M. (October 2010). "A High-Contrast Imaging Survey ofSIM LitePlanet Search Targets". Publications of the Astronomical Society of the Pacific. 122 (896): 1195–1206. arXiv:1007.4315. Bibcode:2010PASP..122.1195T. doi:10.1086/656481. eISSN 1538-3873. ISSN 0004-6280.
14. Gáspár, András; Rieke, George H.; Ballering, Nicholas (29 July 2016). "The Correlation Between Metallicity and Debris Disk Mass". The Astrophysical Journal. 826 (2): 171. arXiv:1604.07403. Bibcode:2016ApJ...826..171G. doi:10.3847/0004-637X/826/2/171. eISSN 1538-4357.