  | |
| Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
|---|---|
| Constellation | Octans |
| Right ascension | 08h 56m 40.97572s [1] |
| Declination | −85° 39′ 47.3476″ [1] |
| Apparent magnitude (V) | 5.42±0.01 [2] |
| Characteristics | |
| Spectral type | A8/9 IV [3] or F0 III [4] |
| U−B color index | +0.07 [5] |
| B−V color index | +0.31 [5] |
| Astrometry | |
| Radial velocity (Rv) | −3.6±2 [6] km/s |
| Proper motion (μ) |
RA: −117.699
mas/
yr
[1] Dec.: +33.964 mas/ yr [1] |
| Parallax (π) | 20.9964 ± 0.0776 mas [1] |
| Distance | 155.3 ± 0.6
ly (47.6 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.95 [7] |
| Details | |
| Mass | 2.06±0.40 [8] M☉ |
| Radius | 2.25±0.11 [9] R☉ |
| Luminosity | 12.63±0.09 [1] L☉ |
| Surface gravity (log g) | 4.04±0.28 [8] cgs |
| Temperature | 7,063±325 [10] K |
| Metallicity [Fe/H] | −0.36 [11] dex |
| Rotational velocity (v sin i) | 115 [12] km/s |
| Age | 1.25 [13] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Zeta Octantis, Latinized from ζ Octantis, is a solitary, [16] yellowish-white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.42, [2] making it faintly visible to the naked eye under ideal conditions. The star is located relatively close at a distance of only 156 light-years based on Gaia DR3 parallax measurements, [1] but is drifting closer with a radial velocity of −3.6 km/s. [6] At its current distance, Zeta Octantis' brightness is diminished by 0.25 magnitudes due to interstellar dust. [17]
This s an evolved A-type star with a stellar classification of A8/9 IV. [3] David S. Evans and colleagues, however, give it a classification of F0 III, [4] which suggests it is already an evolved giant star. It has double the Sun's mass, [8] and 2.25 times the Sun's radius. [9] It radiates around 13 times the luminosity of the Sun [1] from its photosphere at an effective temperature of 7,063 K. [10] Zeta Octantis is estimated to be 1.25 billion years olds based on stellar evolution models by Trevor J. David and Lynne A. Hillenbrand. [13] It has a low metallicity, having only 44% the abundance of heavy metals compared to the Sun. [11] Despite its advanced age, the object spins rapidly with a projected rotational velocity of 115 km/s, [12] resulting in an oblate shape with a equatorial bulge 11% larger than the polar radius. [18]
References
- ^ a b c d e f g 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 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.
- ^ a b 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.
- ^ a b Evans, D. S.; Menzies, A.; Stoy, R. H. (1 December 1959). "Fundamental Data for Southern Stars (Second List)". Monthly Notices of the Royal Astronomical Society. 119 (6): 638–647. Bibcode: 1959MNRAS.119..638E. doi: 10.1093/mnras/119.6.638. eISSN 1365-2966. ISSN 0035-8711.
- ^ a b Mallama, A. (December 2014). "Sloan Magnitudes for the Brightest Stars". Journal of the American Association of Variable Star Observers (JAAVSO). 42 (2): 443. Bibcode: 2014JAVSO..42..443M. ISSN 0271-9053.
- ^ a b Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". Determination of Radial Velocities and Their Applications. 30: 57. Bibcode: 1967IAUS...30...57E.
- ^ 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.
- ^ a b c Stassun, Keivan G.; Oelkers, Ryan J.; Pepper, Joshua; et al. (20 August 2018). "The TESS Input Catalog and Candidate Target List". The Astronomical Journal. 156 (3): 102. arXiv: 1706.00495. Bibcode: 2018AJ....156..102S. doi: 10.3847/1538-3881/aad050. eISSN 1538-3881.
- ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". 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.
- ^ a b Bai, Yu; Liu, JiFeng; Bai, ZhongRui; Wang, Song; Fan, DongWei (2 August 2019). "Machine-learning Regression of Stellar Effective Temperatures in the Second Gaia Data Release". The Astronomical Journal. 158 (2): 93. arXiv: 1906.09695. Bibcode: 2019AJ....158...93B. doi: 10.3847/1538-3881/ab3048. eISSN 1538-3881.
- ^ a b Netopil, Martin (4 May 2017). "Metallicity calibrations for dwarf stars and giants in the Geneva photometric system". Monthly Notices of the Royal Astronomical Society. 469 (3): 3042–3055. arXiv: 1705.00883. Bibcode: 2017MNRAS.469.3042N. doi: 10.1093/mnras/stx1077. eISSN 1365-2966. ISSN 0035-8711.
- ^ a b Huang, Su-Shu (September 1953). "A Statistical Study of the Rotation of the Stars". The Astrophysical Journal. 118: 285. Bibcode: 1953ApJ...118..285H. doi: 10.1086/145751. eISSN 1538-4357. ISSN 0004-637X.
- ^ a b 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.
- ^ 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.
- ^ "Zeta Octantis". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved December 7, 2022.
- ^ 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.
- ^ 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.
- ^ van Belle, Gerard T. (14 March 2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review. 20 (1): 51. arXiv: 1204.2572. Bibcode: 2012A&ARv..20...51V. doi: 10.1007/s00159-012-0051-2. eISSN 1432-0754. ISSN 0935-4956.
| |
| Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
|---|---|
| Constellation | Octans |
| Right ascension | 08h 56m 40.97572s [1] |
| Declination | −85° 39′ 47.3476″ [1] |
| Apparent magnitude (V) | 5.42±0.01 [2] |
| Characteristics | |
| Spectral type | A8/9 IV [3] or F0 III [4] |
| U−B color index | +0.07 [5] |
| B−V color index | +0.31 [5] |
| Astrometry | |
| Radial velocity (Rv) | −3.6±2 [6] km/s |
| Proper motion (μ) |
RA: −117.699
mas/
yr
[1] Dec.: +33.964 mas/ yr [1] |
| Parallax (π) | 20.9964 ± 0.0776 mas [1] |
| Distance | 155.3 ± 0.6
ly (47.6 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.95 [7] |
| Details | |
| Mass | 2.06±0.40 [8] M☉ |
| Radius | 2.25±0.11 [9] R☉ |
| Luminosity | 12.63±0.09 [1] L☉ |
| Surface gravity (log g) | 4.04±0.28 [8] cgs |
| Temperature | 7,063±325 [10] K |
| Metallicity [Fe/H] | −0.36 [11] dex |
| Rotational velocity (v sin i) | 115 [12] km/s |
| Age | 1.25 [13] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Zeta Octantis, Latinized from ζ Octantis, is a solitary, [16] yellowish-white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.42, [2] making it faintly visible to the naked eye under ideal conditions. The star is located relatively close at a distance of only 156 light-years based on Gaia DR3 parallax measurements, [1] but is drifting closer with a radial velocity of −3.6 km/s. [6] At its current distance, Zeta Octantis' brightness is diminished by 0.25 magnitudes due to interstellar dust. [17]
This s an evolved A-type star with a stellar classification of A8/9 IV. [3] David S. Evans and colleagues, however, give it a classification of F0 III, [4] which suggests it is already an evolved giant star. It has double the Sun's mass, [8] and 2.25 times the Sun's radius. [9] It radiates around 13 times the luminosity of the Sun [1] from its photosphere at an effective temperature of 7,063 K. [10] Zeta Octantis is estimated to be 1.25 billion years olds based on stellar evolution models by Trevor J. David and Lynne A. Hillenbrand. [13] It has a low metallicity, having only 44% the abundance of heavy metals compared to the Sun. [11] Despite its advanced age, the object spins rapidly with a projected rotational velocity of 115 km/s, [12] resulting in an oblate shape with a equatorial bulge 11% larger than the polar radius. [18]
References
- ^ a b c d e f g 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 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.
- ^ a b 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.
- ^ a b Evans, D. S.; Menzies, A.; Stoy, R. H. (1 December 1959). "Fundamental Data for Southern Stars (Second List)". Monthly Notices of the Royal Astronomical Society. 119 (6): 638–647. Bibcode: 1959MNRAS.119..638E. doi: 10.1093/mnras/119.6.638. eISSN 1365-2966. ISSN 0035-8711.
- ^ a b Mallama, A. (December 2014). "Sloan Magnitudes for the Brightest Stars". Journal of the American Association of Variable Star Observers (JAAVSO). 42 (2): 443. Bibcode: 2014JAVSO..42..443M. ISSN 0271-9053.
- ^ a b Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". Determination of Radial Velocities and Their Applications. 30: 57. Bibcode: 1967IAUS...30...57E.
- ^ 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.
- ^ a b c Stassun, Keivan G.; Oelkers, Ryan J.; Pepper, Joshua; et al. (20 August 2018). "The TESS Input Catalog and Candidate Target List". The Astronomical Journal. 156 (3): 102. arXiv: 1706.00495. Bibcode: 2018AJ....156..102S. doi: 10.3847/1538-3881/aad050. eISSN 1538-3881.
- ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". 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.
- ^ a b Bai, Yu; Liu, JiFeng; Bai, ZhongRui; Wang, Song; Fan, DongWei (2 August 2019). "Machine-learning Regression of Stellar Effective Temperatures in the Second Gaia Data Release". The Astronomical Journal. 158 (2): 93. arXiv: 1906.09695. Bibcode: 2019AJ....158...93B. doi: 10.3847/1538-3881/ab3048. eISSN 1538-3881.
- ^ a b Netopil, Martin (4 May 2017). "Metallicity calibrations for dwarf stars and giants in the Geneva photometric system". Monthly Notices of the Royal Astronomical Society. 469 (3): 3042–3055. arXiv: 1705.00883. Bibcode: 2017MNRAS.469.3042N. doi: 10.1093/mnras/stx1077. eISSN 1365-2966. ISSN 0035-8711.
- ^ a b Huang, Su-Shu (September 1953). "A Statistical Study of the Rotation of the Stars". The Astrophysical Journal. 118: 285. Bibcode: 1953ApJ...118..285H. doi: 10.1086/145751. eISSN 1538-4357. ISSN 0004-637X.
- ^ a b 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.
- ^ 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.
- ^ "Zeta Octantis". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved December 7, 2022.
- ^ 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.
- ^ 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.
- ^ van Belle, Gerard T. (14 March 2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review. 20 (1): 51. arXiv: 1204.2572. Bibcode: 2012A&ARv..20...51V. doi: 10.1007/s00159-012-0051-2. eISSN 1432-0754. ISSN 0935-4956.