Gamma1 Octantis

γ1 Octantis
Location of γ1 Octantis (circled)
Observation data
Epoch J2000      Equinox ICRS
Constellation Octans
Right ascension 23h 52m 06.47318s
Declination −82° 01′ 07.7636″
Apparent magnitude (V) 5.10
Characteristics
Evolutionary stage red clump
Spectral type G7III
U−B color index +0.60
B−V color index +0.92
Astrometry
Radial velocity (Rv)+15.4±0.1 km/s
Proper motion (μ) RA: −45.670 mas/yr
Dec.: −15.666 mas/yr
Parallax (π)12.1790±0.0552 mas
Distance268 ± 1 ly
(82.1 ± 0.4 pc)
Absolute magnitude (MV)0.55
Details
Mass1.81 M☉
Radius10.3 R☉
Luminosity60 L☉
Surface gravity (log g)2.64 cgs
Temperature5,017 K
Metallicity [Fe/H]−0.34 dex
Rotational velocity (v sin i)1.8 km/s
Other designations
γ1 Oct, 86 G. Octantis, CPD−82°905, FK5 3997, GC 33107, HD 223647, HIP 117689, HR 9032, SAO 258989
Database references
SIMBADdata

Gamma1 Octantis, Latinized from γ1 Octantis, is a single, yellow-hued star in the constellation which includes the southern celestial pole, Octans. Its apparent visual magnitude is 5.10, meaning that in good conditions it is bright enough to be faintly visible to the naked eye.

Distance and proper motion

Based upon an annual parallax shift of 12.2 mas which is taken during opposing points of the Earth's orbit of the sun (with compensation for its eccentricity), the star is about 268 light years away. Its (proper) motion has a net vector at present of receding from the Sun, at +15.4 km/s.

Characteristics

This is an evolved G-type giant star with a stellar classification of G7 III. It is a red clump star, which means it is generating energy through helium fusion at its core. The star has an estimated 1.81 times the mass of the Sun and it has expanded to over 10 times the Sun's radius and is radiating 60 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,017 K.

References

  1. 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.
  2. 1 2 3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry
  3. 1 2 Gontcharov, G. A. (2009). "Red giant clump in the Tycho-2 catalogue". Astronomy Letters. 34 (11): 785–796. arXiv:1607.00619. Bibcode:2008AstL...34..785G. doi:10.1134/S1063773708110078. S2CID 73524157. Vizier catalog entry
  4. 1 2 Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
  5. 1 2 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
  6. 1 2 Gontcharov, G. A. (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.
  7. 1 2 3 Allende Prieto, C.; Lambert, D. L. (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. Vizier catalog entry
  8. 1 2 3 4 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel; Jenkins, Jon M.; Stassun, Keivan; Twicken, Joseph D.; Vanderspek, Roland; Winn, Joshua N. (2023). "Variability Catalog of Stars Observed during the TESS Prime Mission". The Astrophysical Journal Supplement Series. 268 (1): 4. arXiv:2208.11721. Bibcode:2023ApJS..268....4F. doi:10.3847/1538-4365/acdee5.
  9. ↑ Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics. 591: A118. arXiv:1605.07384. Bibcode:2016A&A...591A.118S. doi:10.1051/0004-6361/201628497. S2CID 119258214.
  10. ↑ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. S2CID 54046583. Vizier catalog entry
  11. ↑ "HD 223647". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 7 June 2022.
  12. ↑ 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.
  13. ↑ Eggleton, P. P.; Tokovinin, A. A. (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. S2CID 14878976.