HD 90362 (HR 4092; 47 G. Sextantis) is a solitary star[16] located in the equatorial constellation Sextans. It is faintly visible to the naked eye as a redish-orange-hued point of light with an apparent magnitude of 5.56.[2] Gaia DR3 parallax measurements imply a distance of approximately 460 light-years[1] and it is receding with a heliocentric radial velocity of 35.6 km/s.[6] At its current distance, HD 90362's brightness is diminished by an interstellar extinction of 0.19 magnitudes[17] and it has an absolute magnitude of +0.19.[7]

HD 90362
Location of HD 90362 on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sextans
Right ascension 10h 25m 44.27091s[1]
Declination −07° 03′ 35.3764″[1]
Apparent magnitude (V) 5.56[2]
Characteristics
Evolutionary stage AGB[3]
Spectral type K6 III Fe −0.5[4]
U−B color index +1.86[2]
B−V color index +1.53[2]
Variable type suspected[5]
Astrometry
Radial velocity (Rv)35.60±0.25[6] km/s
Proper motion (μ) RA: −135.763 mas/yr[1]
Dec.: +130.341 mas/yr[1]
Parallax (π)7.127 ± 0.1702 mas[1]
Distance460 ± 10 ly
(140 ± 3 pc)
Absolute magnitude (MV)+0.19[7]
Details
Mass0.44±0.14[8] M
Radius41.1±2.1[9] R
Luminosity252±9[10] L
Surface gravity (log g)0.96+0.02
−0.03
[11] cgs
Temperature3,804[12] K
Metallicity [Fe/H]−0.10±0.05[8] dex
Rotational velocity (v sin i)1.5±1.0[13] km/s
Age11.0+1.9
−1.6
[8] Gyr
Other designations
47 G. Sextantis[14], NSV 18399, BD−06°3146, FK5 2836, GC 14321, HD 90362, HIP 51046, HR 4092, SAO 137557, CCDM J10258-0704A, WDS J10257-0704A, TIC 36881111[15]
Database references
SIMBADdata

HD 90362 is an old population II star[18] with a stellar classification of K6 III Fe −0.5,[4] indicating that it is an evolved K-type giant that has exhausted hydrogen at its core and left the main sequence along with a mild spectral underabundance of iron. It is currently on the asymptotic giant branch, generating energy via the fusion of hydrogen and helium shells around an inert carbon core.[3] It has only 44% the mass of the Sun[8] but at the age of 11 billion years,[8] it has expanded to 41.1 times the radius of the Sun.[9] It radiates 252 times the luminosity of the Sun[10] from its enlarged photosphere at an effective temperature of 3,804 K.[12] HD 90362 is metal deficient with an iron abundance of [Fe/H] = −0.1 or 79.4% of the Sun's[8] and it spins slowly with a projected rotational velocity of approximately 1.5 km/s.[13]

The variability of the star was first detected in 1997 by the Hipparcos mission.[19] It found variations between 5.69 and 5.72 in the Hipparcos passband. As of 2004, its variability has not been confirmed.[20] HD 90362 has an optical companion located 142.6" away along a position angle of 100° as of 2010.[21] It was first observed by M. Scaria in 1981.[21]

References edit

  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 c d 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.
  3. ^ a b Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". The Astronomical Journal. 104: 275. Bibcode:1992AJ....104..275E. doi:10.1086/116239. ISSN 0004-6256. S2CID 121672252.
  4. ^ a b Keenan, Philip C.; McNeil, Raymond C. (October 1989). "The Perkins catalog of revised MK types for the cooler stars". The Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. eISSN 1538-4365. ISSN 0067-0049.
  5. ^ Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. eISSN 1562-6881. ISSN 1063-7729. S2CID 125853869.
  6. ^ a b Famaey, B.; Pourbaix, D.; Frankowski, A.; Van Eck, S.; Mayor, M.; Udry, S.; Jorissen, A. (18 February 2009). "Spectroscopic binaries among Hipparcos M giants". Astronomy & Astrophysics. 498 (2): 627–640. arXiv:0901.0934. Bibcode:2009A&A...498..627F. doi:10.1051/0004-6361/200810698. eISSN 1432-0746. ISSN 0004-6361.
  7. ^ 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.
  8. ^ a b c d e f Feuillet, Diane K.; Bovy, Jo; Holtzman, Jon; Girardi, Léo; MacDonald, Nick; Majewski, Steven R.; Nidever, David L. (20 January 2016). "Determining Ages of APOGEE Giants with Known Distances". The Astrophysical Journal. 817 (1): 40. arXiv:1511.04088. Bibcode:2016ApJ...817...40F. doi:10.3847/0004-637X/817/1/40. eISSN 1538-4357. S2CID 118675933.
  9. ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (April 8, 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. ^ 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.
  12. ^ a b Ting, Yuan-Sen; Conroy, Charlie; Rix, Hans-Walter; Cargile, Phillip (July 8, 2019). "The Payne : Self-consistent ab initio Fitting of Stellar Spectra". The Astrophysical Journal. 879 (2): 69. arXiv:1804.01530. Bibcode:2019ApJ...879...69T. doi:10.3847/1538-4357/ab2331. ISSN 1538-4357. S2CID 54588218.
  13. ^ 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.
  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 90362". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved December 28, 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.
  18. ^ Cacciari, C.; Malagnini, M. L.; Morossi, C.; Rossi, L. (September 1987). "Physical parameters for Population II stars". Astronomy and Astrophysics. 183: 314–318. Bibcode:1987A&A...183..314C. ISSN 0004-6361. S2CID 117292711.
  19. ^ Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M.; Grewing, M.; van Leeuwen, F. (July 1997). "The HIPPARCOS Catalogue". Astronomy and Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P. ISSN 0004-6361.
  20. ^ Samus, N. N.; Durlevich, O. V. (November 2004). "VizieR Online Data Catalog: Combined General Catalogue of Variable Stars (Samus+ 2004)". VizieR Online Data Catalog: II/250. Bibcode:2004yCat.2250....0S.
  21. ^ a b 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. S2CID 119533755.