Theta Octantis
Location of θ Octantis (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Octans[1] |
| Right ascension | 00h 01m 35.70158s[2] |
| Declination | −77° 03′ 56.6092″[2] |
| Apparent magnitude (V) | 4.78[1] |
| Characteristics | |
| Evolutionary stage | red clump[3] |
| Spectral type | K3III[4] |
| U−B color index | +1.41[5] |
| B−V color index | +1.27[5] |
| Astrometry | |
| Radial velocity (Rv) | +22.48±0.17[6] km/s |
| Proper motion (μ) | RA: −57.30[2] mas/yr Dec.: −177.06[2] mas/yr |
| Parallax (π) | 15.02±0.18 mas[2] |
| Distance | 217 ± 3 ly (66.6 ± 0.8 pc) |
| Absolute magnitude (MV) | 0.66[1] |
| Details | |
| Mass | 1.20[7] M☉ |
| Radius | 15.84+0.42 −1.02[6] R☉ |
| Luminosity | 79.2±1.5[6] L☉ |
| Surface gravity (log g) | 2.16[7] cgs |
| Temperature | 4,325+147 −55[6] K |
| Rotational velocity (v sin i) | < 1.0[8] km/s |
| Other designations | |
| θ Oct, CPD−77°1596, FK5 904, GC 33321, HD 224889, HIP 122, HR 9084, SAO 258207[9] | |
| Database references | |
| SIMBAD | data |
θ Octantis, Latinized as Theta Octantis, is a single[10] 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.[1] The star is located approximately 217 light years from the Sun based on parallax,[2] and is drifting further away with a radial velocity of +22.5 km/s.[6]
This is an aging giant star with a stellar classification of K3III,[4] having exhausted the supply of hydrogen at its core then cooled and expanded. It has been catalogued as a red clump giant,[3] which would indicate it is on the horizontal branch and is undergoing core helium fusion. At present it has 16[6] times the radius of the Sun. This star has 1.20[7] times the mass of the Sun and is radiating 79[6] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,325 K.[6]
References
[edit | edit source]- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Vizier catalog entry
- ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Vizier catalog entry
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Vizier catalog entry
- ^ a b c d e f g h Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Gaia DR2 record for this source at VizieR.
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Vizier catalog entry
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Vizier catalog entry
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
