HD 156768

HD 156768

Observation data Epoch J2000      Equinox J2000
Constellation	Ara
A
Right ascension	17^h 22^m 55.22140^s[1]
Declination	−58° 00′ 37.1789″[1]
Apparent magnitude (V)	6.1[2]
B
Right ascension	17^h 22^m 55.20446^s[3]
Declination	−58° 00′ 38.9718″[3]
Apparent magnitude (V)	9.6[2]
Characteristics
A
Spectral type	G8Ib/II[4]
U−B color index	+0.86[5]
B−V color index	+1.07[5]
B
B−V color index	+0.39[6]
Astrometry
A
Radial velocity (Rv)	−9.42±0.13[1] km/s
Proper motion (μ)	RA: −5.959[1] mas/yr Dec.: −15.651[1] mas/yr
Parallax (π)	3.1386 ± 0.0412 mas[1]
Distance	1,040 ± 10 ly (319 ± 4 pc)
Absolute magnitude (MV)	−1.69[7]
B
Radial velocity (Rv)	−9.80±0.20[8] km/s
Proper motion (μ)	RA: −6.006[3] mas/yr Dec.: −14.316[3] mas/yr
Parallax (π)	2.9305 ± 0.0404 mas[3]
Distance	1,110 ± 20 ly (341 ± 5 pc)
Details
HD 156768 A
Mass	4.5[1] M☉
Radius	37[1] R☉
Luminosity	527[1] L☉
Surface gravity (log g)	1.76[1] cgs
Temperature	4,580[1] K
Rotational velocity (v sin i)	2.6±1.0[9] km/s
HD 156768 B
Mass	1.6[10] M☉
Surface gravity (log g)	3.79[10] cgs
Temperature	6,592[10] K
Metallicity [Fe/H]	−0.11[10] dex
Other designations
CPD−57°8478, HD 156768, HIP 85049, HR 6438, SAO 244678
Database references
SIMBAD	data

HD 156768 is a double star in the southern constellation of Ara, with a combined apparent magnitude of 5.86.[11] The brighter component is a sixth magnitude bright giant or supergiant star with a stellar classification of G8Ib/II.[4] The magnitude 9.6 companion lies at an angular separation of 1.81″ along a position angle of 184°.[2]

References

1. 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. Fabricius, C.; Makarov, V. V. (April 2000), "Two-colour photometry for 9473 components of close Hipparcos double and multiple stars", Astronomy and Astrophysics, 356: 141–145, Bibcode:2000A&A...356..141F.
3. 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.
4. Houk, Nancy; Cowley, A. P. (1979), "Michigan catalogue of two-dimensional spectral types for the HD stars", Ann Arbor: Dept. Of Astronomy, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
5. Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N
6. Fabricius, C.; et al. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
7. 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.
8. Kharchenko, N. V.; Scholz, R.-D.; Piskunov, A. E.; Röser, S.; Schilbach, E. (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. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
9. De Medeiros, J. R.; et al. (November 2002), "A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars", Astronomy and Astrophysics, 395: 97–98, arXiv:1312.3474, Bibcode:2002A&A...395...97D, doi:10.1051/0004-6361:20021214
10. Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. (2022). "VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)". Vizier Online Data Catalog. Bibcode:2022yCat.1354....0A.
11. 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. S2CID 119231169.

External links

• HR 6438
• CCDM J17229-5801
• Image HD 156768