Tau Ophiuchi
  | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 18h 03m 04.91992s[1] |
| Declination | −08° 10′ 49.2586″[1] |
| Apparent magnitude (V) | 5.24 (A) / 5.94 (B) [2] |
| Characteristics | |
| Spectral type | F2V(A) / F5V (B) [2] |
| U−B color index | +0.05 (A)[3] |
| B−V color index | +0.38 (A)[3] |
| Astrometry | |
| Radial velocity (Rv) | −38.39[4] km/s |
| Proper motion (μ) | RA: +15.78[1] mas/yr Dec.: -37.79[1] mas/yr |
| Parallax (π) | 19.48±0.66 mas[1] |
| Distance | 167 ± 6 ly (51 ± 2 pc) |
| Orbit[5] | |
| Primary | τ Oph Aa |
| Name | τ Oph Ab |
| Period (P) | 185.243±0.013 days |
| Eccentricity (e) | 0.688±0.055 |
| Periastron epoch (T) | 2,446,738.925±1.232 |
| Argument of periastron (ω) (secondary) | 51.2±0.7° |
| Orbit[5] | |
| Primary | τ Oph A |
| Name | τ Oph B |
| Period (P) | 288.18±0.93 years |
| Semi-major axis (a) | 1.53±0.08″ |
| Eccentricity (e) | 0.656±0.019 |
| Inclination (i) | 63.3±1.5° |
| Longitude of the node (Ω) | 69.0±0.8° |
| Periastron epoch (T) | 1826.69±0.36 |
| Argument of periastron (ω) (secondary) | 46±3° |
| Details | |
| Mass | 1.54 (A) / 1.29 (B)[6] M☉ |
| Surface gravity (log g) | 4.18 (A)[7] cgs |
| Temperature | 6,813 (A)[7] K |
| Other designations | |
| BD−08°4549, CCDM J18031-0811AB, 69 Ophiuchi, HIP 88404, HD 164764+164765, HR 6733+6734, WDS J18031-0811AB | |
| Database references | |
| SIMBAD | data |
Tau Ophiuchi (τ Oph) is a multiple star in the constellation Ophiuchus, approximately 167 light years away based on parallax.[1] Its two main components are two yellow-white main sequence stars, A, of magnitude 5.24 and class F2V, and B, of magnitude 5.94 and class F5V,[2] orbiting each other with a period of 257 years and eccentricity around 0.77.[8] A is reported as a spectroscopic binary with a smaller star of 0.29 solar masses orbiting it every 186 days.[6] An additional component, C, has a separation of 100.8" and magnitude 11.28.[9]
References
[edit]- 1 2 3 4 5 6 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. Vizier catalog entry
- 1 2 3 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.
- 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.
- ↑ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
- 1 2 Branham, Richard L. (2018-11-16). "A new orbit for the binary star Tau Ophiuchi". Astrophysics and Space Science. 363 (12): 252. doi:10.1007/s10509-018-3469-9. ISSN 1572-946X.
- 1 2 Tokovinin, A. (2008). "Comparative statistics and origin of triple and quadruple stars". Monthly Notices of the Royal Astronomical Society. 389 (2): 925–938. arXiv:0806.3263. Bibcode:2008MNRAS.389..925T. doi:10.1111/j.1365-2966.2008.13613.x. S2CID 16452670.
- 1 2 David, Trevor J.; Hillenbrand, Lynne A. (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. S2CID 33401607. Vizier catalog entry
- ↑ Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: A69. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. Vizier catalog entry
- ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Vizier catalog entry
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