Iota Aquilae

Iota Aquilae, Latinized from ι Aquilae, is the Bayer designation for a star in the equatorial constellation of Aquila. It has the traditional name Al Thalimain /ælˌθælɪˈmn/, which it shares with λ Aquilae. The name is derived from the Arabic term الظليمین al-ẓalīmayn meaning "The Two Ostriches". With an apparent visual magnitude of 4.364, this star is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 8.34 ± 0.79 mas, it is located at a distance of around 390 light-years (120 parsecs) from Earth. At that distance, the visual magnitude of the star is diminished by 0.15 from extinction caused by intervening gas and dust.

Iota Aquilae
Location of ι Aquilae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 19h 36m 43.27606s
Declination –01° 17 11.7611
Apparent magnitude (V) 4.364
Characteristics
Spectral type B5 III
U−B color index –0.428
B−V color index –0.083
R−I color index –0.08
Astrometry
Radial velocity (Rv)–21.4 km/s
Proper motion (μ) RA: –0.87 mas/yr
Dec.: –20.39 mas/yr
Parallax (π)8.34 ± 0.79 mas
Distance390 ± 40 ly
(120 ± 10 pc)
Absolute magnitude (MV)−1.01
Details
Mass4.8 ± 0.3 M
Radius5.5 ± 0.5 R
Luminosity851 L
Surface gravity (log g)3.64 ± 0.05 cgs
Temperature14,552 K
Metallicity [Fe/H]0.09±0.04 dex
Rotational velocity (v sin i)55 km/s
Age100 ± 8 Myr
Other designations
Al Thalimain, ι Aql, 41 Aql, BD-01° 3782, HD 184930, HIP 96468, HR 7447, SAO 143597.
Database references
SIMBADdata

Although Iota Aquilae is listed in star catalogues as a giant star, calculations of its dimension show that in reality it is a main-sequence star. It has nearly five times the mass of the Sun and five to six times the Sun's radius. It is emitting 851 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 14,552 K, giving it the blue-white hue of a B-type star. The projected rotational velocity of this star is 55 km/s. Even though it is only around 100 million years old, it has already spent 91% of its allotted lifetime on the main sequence.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.