Iota Aquilae
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 36m 43.2777s |
| Declination | -01° 17′ 11.763″ |
| Apparent magnitude (V) | 4.349 |
| Characteristics | |
| Spectral type | B5III |
| U−B color index | -0.44 |
| B−V color index | -0.08 |
| R−I color index | -0.08 |
| Astrometry | |
| Radial velocity (Rv) | -21.4 km/s |
| Proper motion (μ) | RA: 1.89 mas/yr Dec.: -20.75 mas/yr |
| Parallax (π) | 10.61 ± 0.94 mas |
| Distance | 310 ± 30 ly (94 ± 8 pc) |
| Absolute magnitude (MV) | -4.27 |
| Details | |
| Radius | 4.3[1] R☉ |
| Temperature | 14,552[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
|
Iota Aquilae (ι Aql, ι Aquilae) is a binary star in the constellation Aquila. It has the traditional name Al Thalimain, which it shares with λ Aquilae. The name is derived from the Arabic term الثالمين ath-thalīmain meaning "The Two Ostriches".
In Chinese, 右旗 (Yòu Qí), meaning Right Flag, refers to an asterism consisting of ι Aquilae, μ Aquilae, σ Aquilae, δ Aquilae, ν Aquilae, 42 Aquilae, HD 184701, κ Aquilae and 56 Aquilae.[2] Consequently, ι Aquilae itself is known as 右旗五 (Yòu Qí wu, English: the Fifth Star of Right Flag.)[3]
Iota Aquilae is a blue-white B-type star with an apparent magnitude of +4.36. Although it is listed in star catalogues as a giant star, calculations of its dimension show that in reality it is a dwarf.[4] It is approximately 307[5] light years from Earth and has an optical companion with an apparent magnitude of +13,0 mag in a distance of 47,0".
[edit] References
- ^ a b Underhill, A. B. et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society 189: 601–605, Bibcode 1979MNRAS.189..601U
- ^ (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) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 3 日
- ^ Iota Aquilae by Jim Kaler
- ^ University of Illinois - Al Thalimain Posterior
[edit] External links
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