  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Octans |
| Right ascension | 00h 01m 35.70158s [1] |
| Declination | −77° 03′ 56.6092″ [1] |
| Apparent magnitude (V) | 4.78 [2] |
| Characteristics | |
| Spectral type | K3III [3] |
| U−B color index | +1.41 [4] |
| B−V color index | +1.27 [4] |
| Astrometry | |
| Radial velocity (Rv) | +22.48±0.17 [5] km/s |
| Proper motion (μ) |
RA: −57.30
[1]
mas/
yr Dec.: −177.06 [1] mas/ yr |
| Parallax (π) | 15.02 ± 0.18 mas [1] |
| Distance | 217 ± 3
ly (66.6 ± 0.8 pc) |
| Absolute magnitude (MV) | 0.66 [2] |
| Details | |
| Mass | 1.20 [6] M☉ |
| Radius | 15.84+0.42 −1.02 [5] R☉ |
| Luminosity | 79.2±1.5 [5] L☉ |
| Surface gravity (log g) | 2.16 [6] cgs |
| Temperature | 4,325+147 −55 [5] K |
| Rotational velocity (v sin i) | < 1.0 [7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
θ Octantis, Latinized as Theta Octantis, is a single [9] star in the southern circumpolar constellation of Octans, near the constellation border with Hydrus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.78. [2] The star is located approximately 217 light years from the Sun based on parallax, [1] and is drifting further away with a radial velocity of +22.5 km/s. [5]
This is an aging giant star with a stellar classification of K3III, [3] having exhausted the supply of hydrogen at its core then cooled and expanded. It has been catalogued as a red clump giant, [10] which would indicate it is on the horizontal branch and is undergoing core helium fusion. At present it has 16 [5] times the radius of the Sun. This star has 1.20 [6] times the mass of the Sun and is radiating 79 [5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,325 K. [5]
References
- ^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752. Bibcode: 2007A&A...474..653V. doi: 10.1051/0004-6361:20078357. S2CID 18759600.
- ^ 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 Houk, Nancy; Cowley, A. P. (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 1. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode: 1978mcts.book.....H.
- ^ 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 c d e f g h 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.
- ^ 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
- ^ 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
-
^
"tet Oct".
SIMBAD.
Centre de données astronomiques de Strasbourg. Retrieved 2019-08-30.
{{ cite web}}: CS1 maint: postscript ( link) - ^ 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.
- ^ 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
| |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Octans |
| Right ascension | 00h 01m 35.70158s [1] |
| Declination | −77° 03′ 56.6092″ [1] |
| Apparent magnitude (V) | 4.78 [2] |
| Characteristics | |
| Spectral type | K3III [3] |
| U−B color index | +1.41 [4] |
| B−V color index | +1.27 [4] |
| Astrometry | |
| Radial velocity (Rv) | +22.48±0.17 [5] km/s |
| Proper motion (μ) |
RA: −57.30
[1]
mas/
yr Dec.: −177.06 [1] mas/ yr |
| Parallax (π) | 15.02 ± 0.18 mas [1] |
| Distance | 217 ± 3
ly (66.6 ± 0.8 pc) |
| Absolute magnitude (MV) | 0.66 [2] |
| Details | |
| Mass | 1.20 [6] M☉ |
| Radius | 15.84+0.42 −1.02 [5] R☉ |
| Luminosity | 79.2±1.5 [5] L☉ |
| Surface gravity (log g) | 2.16 [6] cgs |
| Temperature | 4,325+147 −55 [5] K |
| Rotational velocity (v sin i) | < 1.0 [7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
θ Octantis, Latinized as Theta Octantis, is a single [9] star in the southern circumpolar constellation of Octans, near the constellation border with Hydrus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.78. [2] The star is located approximately 217 light years from the Sun based on parallax, [1] and is drifting further away with a radial velocity of +22.5 km/s. [5]
This is an aging giant star with a stellar classification of K3III, [3] having exhausted the supply of hydrogen at its core then cooled and expanded. It has been catalogued as a red clump giant, [10] which would indicate it is on the horizontal branch and is undergoing core helium fusion. At present it has 16 [5] times the radius of the Sun. This star has 1.20 [6] times the mass of the Sun and is radiating 79 [5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,325 K. [5]
References
- ^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752. Bibcode: 2007A&A...474..653V. doi: 10.1051/0004-6361:20078357. S2CID 18759600.
- ^ 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 Houk, Nancy; Cowley, A. P. (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 1. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode: 1978mcts.book.....H.
- ^ 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 c d e f g h 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.
- ^ 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
- ^ 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
-
^
"tet Oct".
SIMBAD.
Centre de données astronomiques de Strasbourg. Retrieved 2019-08-30.
{{ cite web}}: CS1 maint: postscript ( link) - ^ 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.
- ^ 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