HD 165259

HD 165259
Observation data
Epoch J2000.0 (ICRS)      Equinox ICRS
Constellation Apus
A
Right ascension 18h 12m 34.08358s
Declination −73° 40′ 20.7691″
Apparent magnitude (V) 5.91
B
Right ascension 18h 12m 33.47381s
Declination −73° 40′ 20.9419″
Apparent magnitude (V) 9.03
Characteristics
A
Evolutionary stage main sequence
Spectral type F5V
U−B color index +0.05
B−V color index +0.46
B
Spectral type G1 V
U−B color index +0.74
B−V color index +1.06
Astrometry
Radial velocity (Rv)13.1±1 km/s
Absolute magnitude (MV)+2.74
A
Proper motion (μ) RA: −91.400 mas/yr
Dec.: −254.341 mas/yr
Parallax (π)23.6778±0.0399 mas
Distance137.7 ± 0.2 ly
(42.23 ± 0.07 pc)
B
Proper motion (μ) RA: −62.130 mas/yr
Dec.: −241.999 mas/yr
Parallax (π)23.7101±0.0338 mas
Distance137.6 ± 0.2 ly
(42.18 ± 0.06 pc)
Orbit
PrimaryA
SecondaryB
Period (P)450 yr
Semi-major axis (a)2.014″
Eccentricity (e)0.3
Inclination (i)46.7°
Longitude of the node (Ω)65.3°
Periastron epoch (T)2147.2
Argument of periastron (ω)
(primary)		348.8°
Orbit
PrimaryAa
SecondaryAb
Period (P)44.2 yr
Semi-major axis (a)0.373″
Eccentricity (e)0
Inclination (i)83.5°
Longitude of the node (Ω)105.2°
Periastron epoch (T)2027.22
Argument of periastron (ω)
(primary)		0°
Details
Aa
Mass1.46 M☉
Radius2.04 R☉
Luminosity6.2 L☉
Surface gravity (log g)3.92 cgs
Temperature6,411±218 K
Metallicity [Fe/H]+0.26 dex
Rotational velocity (v sin i)<5 km/s
Age1.8+0.1
−0.2 Gyr
Ab
Mass0.73 M☉
B
Mass0.82 M☉
Surface gravity (log g)4.3 cgs
Temperature5,328 K
Metallicity [Fe/H]−0.22 dex
Other designations
67 G. Apodis, CD−73°1348, CPD−73°1888, GC 24731, HD 165259, HIP 89234, HR 6751, SAO 257571, WDS J18126-7340AB
Database references
SIMBADdata

HD 165259, also known as HR 6751, is a triple star system located in the southern circumpolar constellation of Apus. It has an apparent magnitude of 5.86, making it faintly visible to the naked eye. Parallax measurements place the system at a distance of 138 light years, and it is currently receding with a heliocentric radial velocity of 13.1 km/s.

HD 165259 consists of two main sequence stars, with stellar classifications of F5 V and G1 V, separated by two arc-seconds as of 2020. Speckle interferometry in 2008 revealed the primary to be a close binary itself, with the two components separated by 0.3″. By 2020, the separation had decreased to 0.2″. The outer pair take 542 years to complete a revolution while the inner pair complete their orbit within 32 years.

At present the primary is somewhat more massive than the Sun and a slightly enlarged radius of 2.0 R☉ as it is nearing the end of its main sequence life. It radiates at 6.2 times the luminosity of the Sun from its photosphere at an effective temperature of 6,411 K, giving a yellow-white hue. HD 165259A has an iron abundance 82% above solar levels, making it metal enriched. It is estimated to be nearly 2 billion years old and has a projected rotational velocity of less than 5 km/s. HD 165259B has 82% the mass of the Sun and an effective temperature of 5,328 K, giving an orange glow. The faint star orbiting the primary has a mass 73% that of the Sun.

References

  1. ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  2. 1 2 3 4 5 6 7 8 9 10 11 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.
  3. 1 2 Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (March 2002). "The Tycho double star catalogue". Astronomy & Astrophysics. 384 (1): 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822. ISSN 0004-6361.
  4. 1 2 3 4 5 6 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.
  5. 1 2 Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations −90° to −53°. Bibcode:1975mcts.book.....H.
  6. 1 2 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.
  7. 1 2 3 4 Corbally, C. J. (August 1984). "Close visual binaries. I - MK classifications". The Astrophysical Journal Supplement Series. 55: 657. Bibcode:1984ApJS...55..657C. doi:10.1086/190973. eISSN 1538-4365. ISSN 0067-0049.
  8. 1 2 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. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
  9. 1 2 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.
  10. 1 2 3 4 5 6 7 Tokovinin, Andrei (2025). "Orbits of Six Triple Systems". The Astronomical Journal. 169 (3): 124. arXiv:2501.04807. Bibcode:2025AJ....169..124T. doi:10.3847/1538-3881/ada3c6.
  11. 1 2 3 David, Trevor J.; Hillenbrand, Lynne A. (12 May 2015). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. eISSN 1538-4357.
  12. 1 2 Casagrande, L.; Schönrich, R.; Asplund, M.; Cassisi, S.; Ramírez, I.; Meléndez, J.; Bensby, T.; Feltzing, S. (26 May 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. eISSN 1432-0746. ISSN 0004-6361.
  13. 1 2 3 Nordström, B.; Mayor, M.; Andersen, J.; Holmberg, J.; Pont, F.; Jørgensen, B. R.; Olsen, E. H.; Udry, S.; Mowlavi, N. (16 April 2004). "The Geneva-Copenhagen survey of the Solar neighbourhood". Astronomy & Astrophysics. 418 (3): 989–1019. arXiv:astro-ph/0405198. Bibcode:2004A&A...418..989N. doi:10.1051/0004-6361:20035959. eISSN 1432-0746. ISSN 0004-6361.
  14. 1 2 3 4 Anders, F.; et al. (February 2022). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5". Astronomy & Astrophysics. 658: A91. arXiv:2111.01860. Bibcode:2022A&A...658A..91A. doi:10.1051/0004-6361/202142369. eISSN 1432-0746. ISSN 0004-6361.
  15. ↑ 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.
  16. ↑ "HR 6635". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved August 15, 2022.
  17. 1 2 Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.
  18. ↑ Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I. (2010). "Speckle Interferometry at the Blanco and SOAR Telescopes in 2008 and 2009". The Astronomical Journal. 139 (2): 743–756. arXiv:0911.5718. Bibcode:2010AJ....139..743T. doi:10.1088/0004-6256/139/2/743. S2CID 26379213.
  19. ↑ Tokovinin, Andrei (14 March 2014). "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs". The Astronomical Journal. 147 (4): 87. arXiv:1401.6827. Bibcode:2014AJ....147...87T. doi:10.1088/0004-6256/147/4/87. eISSN 1538-3881. ISSN 0004-6256.