HD 162337, also known as HR 6646 or rarely 65 G. Apodis, is a solitary orange-hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.35,[2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively far at a distance of 989 light-years based on Gaia DR3 parallax measurements,[1] but it is drifting closer with a heliocentric radial velocity of −3.3 km/s.[5] At its current distance, HD 162337's brightness is heavily diminished by 0.45 magnitudes due to interstellar extinction[13] and it has an absolute magnitude of −0.61.[6]

HD 162337
Location of HD 162337 on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Apus
Right ascension 18h 05m 26.85525s[1]
Declination −81° 29′ 11.6368″[1]
Apparent magnitude (V) 6.35±0.01[2]
Characteristics
Spectral type K3/4 III[3]
U−B color index +1.75[4]
B−V color index +1.50[4]
Astrometry
Radial velocity (Rv)−3.3±0.4[5] km/s
Proper motion (μ) RA: +28.344 mas/yr[1]
Dec.: −48.347 mas/yr[1]
Parallax (π)3.2987 ± 0.0286 mas[1]
Distance989 ± 9 ly
(303 ± 3 pc)
Absolute magnitude (MV)−0.61[6]
Details
Radius42.0+4.2
−4.1
[7] or 67.8±1.6[1] R
Luminosity495±13[7] or 1,055+28
−27
[1] L
Surface gravity (log g)0.71±0.01[8] cgs
Temperature4,186±122[9] K
Metallicity [Fe/H]−0.66[8] dex
Rotational velocity (v sin i)<1.0[10] km/s
Other designations
65 G. Apodis[11], CD−81°673, CPD−81°799, FK5 3990, GC 24431, HD 162337, HIP 88599, HR 6646, SAO 258787[12]
Database references
SIMBADdata

HD 162337 has a stellar classification of K3/4 III,[3] indicating that it is an evolved star with the characteristics of a K3 and K4 giant star. It has expanded to 42 times the radius of the Sun[7] and now radiates 495 times the luminosity of the Sun[7] from its enlarged photosphere at an effective temperature of 4,186 K.[9] However, Gaia DR3 stellar evolution models give a larger radius of 67.8±1.6 R[1] and a higher luminosity of 1,055+28
−27
 L
.[1] HD 162337 is metal deficient with an iron abundance 21.9% that of the Sun's ([Fe/H] = −0.66)[8] and it spins too slowly for its projected rotational velocity to measured accurately.[10]

References

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  1. ^ a b c d e f g h i 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, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars: Declinations −90° to −53°. Vol. 1. Bibcode:1975mcts.book.....H.
  4. ^ a b Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
  5. ^ a b 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.
  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 d 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.
  8. ^ a b c Poggio, E.; Recio-Blanco, A.; Palicio, P. A.; Re Fiorentin, P.; de Laverny, P.; Drimmel, R.; Kordopatis, G.; Lattanzi, M. G.; Schultheis, M.; Spagna, A.; Spitoni, E. (30 September 2022). "The chemical signature of the Galactic spiral arms revealed by Gaia DR3". Astronomy & Astrophysics. 666: L4. arXiv:2206.14849. Bibcode:2022A&A...666L...4P. doi:10.1051/0004-6361/202244361. eISSN 1432-0746. ISSN 0004-6361.
  9. ^ 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.
  10. ^ a b 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.
  11. ^ 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.
  12. ^ "HD 128294". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 20, 2015.
  13. ^ 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.