Iota Boötis
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 16m 09.92995s[1] |
| Declination | +51° 22′ 02.0267″[1] |
| Apparent magnitude (V) | 4.75[2] |
| Characteristics | |
| Spectral type | A9 V[2] |
| U−B color index | 0.06 |
| B−V color index | 0.2 |
| R−I color index | 0.09 |
| Variable type | Delta Scuti variable |
| Astrometry | |
| Radial velocity (Rv) | -18.7 km/s |
| Proper motion (μ) | RA: -149.39[1] mas/yr Dec.: +88.72[1] mas/yr |
| Parallax (π) | 34.40 ± 0.19 mas[1] |
| Distance | 94.8 ± 0.5 ly (29.1 ± 0.2 pc) |
| Details | |
| Mass | 2.3[2] M☉ |
| Radius | 1.0[2] R☉ |
| Luminosity | 11[2] L☉ |
| Surface gravity (log g) | 4.80[2] cgs |
| Temperature | 10,560 ± 340[2] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) | |
| Database references | |
| SIMBAD | data |
Iota Boötis (ι Boo, ι Boötis) is a star system in the constellation Boötes. It has the traditional name Asellus Secundus (Latin for "second donkey colt")[3] and the Flamsteed designation 21 Boötis.
This star, along with the other Aselli (θ Boo and κ Boo) and λ Boo, were Al Aulād al Dhiʼbah (أولاد الضّباع - al aulād al dhiʼb), "the Whelps of the Hyenas".[4]
In Chinese, 梗河 (Tiān Qiāng), meaning Celestial Spear, refers to an asterism consisting of ι Boötis, κ2 Boötis and θ Boötis.[5] Consequently, ι Boötis itself is known as 天槍二 (Tiān Qiāng èr, English: the Second Star of Celestial Spear.)[6]
Iota Boötis is a double star, with components at an angular distance of 38.6 arcseconds, easily separated with binoculars. It is approximately 97 light years from Earth.
Components
The primary component, Iota Boötis A, is a white A-type main sequence dwarf with a mean apparent magnitude of +4.75. It is classified as a Delta Scuti type variable star and its brightness varies from magnitude +4.73 to +4.78. The companion, Iota Boötis B, is a magnitude +8.27 star belonging to spectral class A2.
References
- ^ a b c d e 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
- ^ a b c d e f g 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
- ^ Star Name - R.H.Allen p.105
- ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York: Dover Publications Inc, p. 105, ISBN 0-486-21079-0, retrieved 2010-12-12
- ^ Template:Zh icon 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.
- ^ Template:Zh icon 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.
External links
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