HD 167096, also known as HR 6818 or rarely 4 G. Coronae Australis, is a binary star[16] located in the southern constellation Corona Australis. It has an apparent magnitude of 5.45,[2] making it faintly visible to the naked eye. The system is located relatively close at a distance of 224 light years based on Gaia DR3 parallax measurements[1] but is drifting closer with a poorly constrained heliocentric radial velocity of −27 km/s.[5] At its current distance HD 167096's brightness is diminished by three tenths of a magnitudes due to interstellar dust[17] and it has an absolute magnitude of +0.64.[6]

HD 167096
Location of HD 167096 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Corona Australis
Right ascension 18h 15m 53.45211s[1]
Declination −44° 12′ 23.2322″[1]
Apparent magnitude (V) 5.45±0.01[2]
Characteristics
Spectral type G8/K0 III[3]
B−V color index +0.96[4]
Astrometry
Radial velocity (Rv)−27±13.7[5] km/s
Proper motion (μ) RA: +67.283 mas/yr[1]
Dec.: +12.211 mas/yr[1]
Parallax (π)14.5746 ± 0.4724 mas[1]
Distance224 ± 7 ly
(69 ± 2 pc)
Absolute magnitude (MV)+0.64[6]
Orbit[7]
Period (P)1.811595±0.102779 yr
Semi-major axis (a)8.1±0.9 mas
Eccentricity (e)0.00
Details
A
Mass1.11±0.51[8] M
Radius8.92±0.45[9] R
Luminosity32.4±0.7[10] L
Surface gravity (log g)2.51±0.46[8] cgs
Temperature4,886±123[11] K
Metallicity [Fe/H]−0.02[12] dex
Rotational velocity (v sin i)<1.6[13] km/s
Other designations
4 G. Coronae Australis[14], CD−44°12456, CPD−44°9034, GC 24892, HD 167096, HIP 89507, HR 6818, SAO 228854, WDS 18159-4412[15]
Database references
SIMBADdata

The primary has a stellar classification of G8/K0 III,[3] indicating that it is an evolved red giant with the characteristics of a G8 and K0 giant star. It has 1.11 times the mass of the Sun[8] but it has expanded to 8.92 times the Sun's radius.[9] It radiates 32.4 times the luminosity of the Sun[10] from its enlarged photosphere at an effective temperature of 4,886 K,[11] giving it an orangish-yellow hue. It has a near solar metallicity at [Fe/H] = −0.02[12] and spins too slowly for its projected rotational velocity to be measured accurately. This is a binary star that completes a circular orbit within 1.81 years.[7] Since the two components have a separation of only 8.1 mas, it makes it difficult to measure their individual properties.[7]

References

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  1. ^ a b c d e 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 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. S2CID 17128864.
  3. ^ a b Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars: Declinations −53° to −40°. Vol. 2. Bibcode:1978mcts.book.....H.
  4. ^ Corben, P. M. (1966). "Photoelectric magnitudes and colours for bright southern stars". Monthly Notes of the Astronomical Society of South Africa. 25: 44. Bibcode:1966MNSSA..25...44C. ISSN 0024-8266.
  5. ^ a b Kharchenko, N.V.; Scholz, R.-D.; Piskunov, A.E.; Röser, S.; Schilbach, E. (November 2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889–896. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. eISSN 1521-3994. ISSN 0004-6337. S2CID 119323941.
  6. ^ a b 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. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  7. ^ a b c Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (October 2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: A69. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. eISSN 1432-0746. ISSN 0004-6361. S2CID 122594428.
  8. ^ a b c Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361. S2CID 13365201.
  9. ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants. Surface brightness relations calibrated by interferometry". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361. S2CID 6077801.
  10. ^ a b 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.
  11. ^ a b 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. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
  12. ^ a b Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361. S2CID 131780028.
  13. ^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars V: Southern stars *". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361. S2CID 54046583.
  14. ^ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  15. ^ "HD 167096". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved March 18, 2023.
  16. ^ Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. eISSN 1365-2966. ISSN 0035-8711. S2CID 14878976.
  17. ^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711. S2CID 118879856.