Theta Boötis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 25m 11.79703s[1] |
| Declination | +51° 51′ 02.6769″[1] |
| Apparent magnitude (V) | 4.05[2] |
| Characteristics | |
| Spectral type | F7 V[2] |
| U−B color index | −0.02[3] |
| B−V color index | +0.50[2] |
| R−I color index | 0.25 |
| Astrometry | |
| Radial velocity (Rv) | −11.60[4] km/s |
| Proper motion (μ) | RA: -235.40[1] mas/yr Dec.: -399.07[1] mas/yr |
| Parallax (π) | 68.82 ± 0.14[1] mas |
| Distance | 47.39 ± 0.10 ly (14.53 ± 0.03 pc) |
| Details | |
| Mass | 1.3[2] M☉ |
| Radius | 1.733 ± 0.011[5] R☉ |
| Luminosity | 4.131 ± 0.096[5] L☉ |
| Surface gravity (log g) | 4.12[2] cgs |
| Temperature | 6265 ± 41[5] K |
| Metallicity [Fe/H] | 0.02[6] dex |
| Rotational velocity (v sin i) | 29.2[7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) | |
| Database references | |
| SIMBAD | data |
Theta Boötis (θ Boo, θ Boötis) is a star in the constellation Boötes. It has the traditional name Asellus Primus (Latin for "first donkey colt")[8] and the Flamsteed designation 23 Boötis. This star, along with the other Aselli (ι Boo and κ Boo) and λ Boo, were Aulād al Dhiʼbah (أولاد الضّباع - aulād al dhiʼb), "the Whelps of the Hyenas".[9]
In Chinese, 天枪 (Tiān Qiāng), meaning Celestial Spear, refers to an asterism consisting of θ Boötis, κ2 Boötis and ι Boötis.[10] Consequently, θ Boötis itself is known as 天枪三 (Tiān Qiāng sān, English: the Third Star of Celestial Spear.)[11]
Properties
Theta Boötis has apparent magnitude +4.05 and belongs to the spectral class F7V. It is approximately 47 light years from Earth. From about 4300 BC until 3942 BC, it was the closest star to the celestial north pole visible to the naked eye, although it was still too dim to be regarded as a pole star.
There is a nearby 11th magnitude optical companion star about 70 arcseconds away. This is a class M2.5 dwarf that is separated by a minimum of 1,000 AUs. It is uncertain whether they are gravitationally bound, but they do have a common motion through space and so the two stars probably share a common origin.[12][13]
References
- 1 2 3 4 5 van Leeuwen, F. (November 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 - 1 2 3 4 5 Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series, 85 (3): 1015–1019, Bibcode:1990A&AS...85.1015M
- ↑ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data. SIMBAD, Bibcode:1986EgUBV........0M
- ↑ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
- 1 2 3 Boyajian, Tabetha S.; et al. (February 2012), "Stellar Diameters and Temperatures. I. Main-sequence A, F, and G Stars", The Astrophysical Journal, 746 (1): 101, arXiv:1112.3316, Bibcode:2012ApJ...746..101B, doi:10.1088/0004-637X/746/1/101. See Table 10.
- ↑ Prugniel, P.; Vauglin, I.; Koleva, M. (2011). "The atmospheric parameters and spectral interpolator for the MILES stars". Astronomy & Astrophysics. 531: A165. arXiv:1104.4952. Bibcode:2011A&A...531A.165P. doi:10.1051/0004-6361/201116769.
- ↑ Schröder, C.; et al. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377.
- ↑ Star Name - R.H.Allen p.105
- ↑ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc, p. 105, ISBN 0-486-21079-0, retrieved 2010-12-12
- ↑ (Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ↑ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ↑ Kaler, James, "Asellus Primus", Stars, University of Illinois, retrieved 2016-01-07.
- ↑ Lépine, Sébastien; Bongiorno, Bethany (March 2007), "New Distant Companions to Known Nearby Stars. II. Faint Companions of Hipparcos Stars and the Frequency of Wide Binary Systems", The Astronomical Journal, 133 (3): 889−905, arXiv:astro-ph/0610605, Bibcode:2007AJ....133..889L, doi:10.1086/510333.
External links
- CCDM J14252+5151
- HR 5404
- Image Theta Boötis
- Theta Bootis by Professor Jim Kaler.