  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Octans |
| Right ascension | 23h 52m 06.47318s[1] |
| Declination | −82° 01′ 07.7636″[1] |
| Apparent magnitude (V) | 5.10[2] |
| Characteristics | |
| Evolutionary stage | red clump[3] |
| Spectral type | G7III[4] |
| U−B color index | +0.60[5] |
| B−V color index | +0.92[5] |
| Astrometry | |
| Radial velocity (Rv) | +15.4±0.1[6] km/s |
| Proper motion (μ) | RA: −45.670[1] mas/yr Dec.: −15.666[1] mas/yr |
| Parallax (π) | 12.1790±0.0552 mas[1] |
| Distance | 268 ± 1 ly (82.1 ± 0.4 pc) |
| Absolute magnitude (MV) | 0.55[2] |
| Details | |
| Mass | 1.81[7] M☉ |
| Radius | 10.3[8] R☉ |
| Luminosity | 60[8] L☉ |
| Surface gravity (log g) | 2.64[7] cgs |
| Temperature | 5,017[8] K |
| Metallicity [Fe/H] | −0.34[9] dex |
| Rotational velocity (v sin i) | 1.8[10] km/s |
| Other designations | |
| γ1 Oct, 86 G. Octantis, CPD−82°905, FK5 3997, GC 33107, HD 223647, HIP 117689, HR 9032, SAO 258989[11][12] | |
| Database references | |
| SIMBAD | data |
Gamma1 Octantis, Latinized from γ1 Octantis, is a single,[13] yellow-hued star in the constellation which includes the southern celestial pole, Octans. Its apparent visual magnitude is 5.10,[2] meaning that in good conditions it is bright enough to be faintly visible to the naked eye.
Distance and proper motion
[edit]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),[1] 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.[6]
Characteristics
[edit]This is an evolved G-type giant star with a stellar classification of G7 III.[4] It is a red clump star,[3] 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[7] 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.[8]
References
[edit]- ^ a b c d e f 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.
- ^ a b c 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
- ^ a b 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
- ^ a b 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.
- ^ a b 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
- ^ a b 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.
- ^ a b c 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
- ^ a b c d 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.
- ^ 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.
- ^ 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
- ^ "HD 223647". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 7 June 2022.
- ^ 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.
- ^ 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.
