20 Aquilae

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Template:Short description

20 Aquilae
File:20AqlLightCurve.png
A light curve for 20 Aquilae, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension Template:RA[2]
Declination Template:DEC[2]
Apparent magnitude (V) 5.362[3]
Characteristics
Spectral type B3 V,[4] B3 IV,[5] or B2/3 II[6]
B−V Template:Engvar +0.088[3]
Astrometry
Radial velocity (Rv)Script error: No such module "val".[7] km/s
Proper motion (μ) RA: +14.040[2] mas/yr
Dec.: –6.814[2] mas/yr
Parallax (π)3.5374±0.1720 mas[2]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)−2.02[8]
Details
MassScript error: No such module "val".[9] Template:Solar mass
Luminosity (bolometric)7,284[3] Template:Solar luminosity
Temperature18,700[3] K
Rotational velocity (v sin i)Script error: No such module "val".[4] km/s
AgeScript error: No such module "val".[9] Myr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Template:Odlist[10]
Database references
SIMBADdata

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20 Aquilae, abbreviated 20 Aql, is an irregular variable[11] star in the equatorial constellation of Aquila. 20 Aquilae is its Flamsteed designation. It ranges in magnitude from a peak of 5.33 down to 5.36, which is bright enough for the star to be visible to the naked eye.[12] The estimated distance to this star is around 920 light years, based upon an annual parallax shift of Script error: No such module "val"..[2] The star is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.[7]

There has been some disagreement over the stellar classification of this star. Buscombe (1962) listed a class of B3 IV,[5] which suggests a B-type subgiant star that has exhausted the hydrogen at its core and is expanding off the main sequence. Lesh (1968)[13] and Braganca et al. (2012)[4] matched a B-type main sequence star with a class of B3 V. However, Houk and Swift (1999) found a class of B2/3 II,[6] indicating this is an evolved bright giant.

The star is about 28[9] million years old with a high rate of spin, showing a projected rotational velocity of 133 km/s.[4] It has 8.6[9] times the mass of the Sun and is radiating 7,284 times the Sun's luminosity from its photosphere at an effective temperature of 18,700 K.[3]

References

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Template:Stars of Aquila