Iota Boötis
 Location of ι Boötis (circled) | |
| 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[1] mas |
| 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 | |
Asellus Secondus, 21 Boötis, BD+52°1784, FK5 528, HD 125161, HIP 69713, HR 5350, SAO 29071, Wo 9474. | |
| 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 (ألعولد ألذعب - 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 天槍三 (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, a spectroscopic binary,[citation needed] 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
- ↑ 1.0 1.1 1.2 1.3 1.4 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
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 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
- ↑ (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.
External links
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