Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquila |
Right ascension | 19h 19m 39.34802s [2] |
Declination | +12° 22′ 28.8457″ [2] |
Apparent magnitude (V) | 5.51 - 5.56 [3] |
Characteristics | |
Spectral type | F0 III [4] |
U−B color index | +0.182 [5] |
B−V color index | +0.257 [5] |
Variable type | δ Sct [3] |
Astrometry | |
Radial velocity (Rv) | +4.36 [4] km/s |
Proper motion (μ) |
RA: +4.249
[2]
mas/
yr Dec.: +16.199 [2] mas/ yr |
Parallax (π) | 9.5836 ± 0.0768 mas [2] |
Distance | 340 ± 3
ly (104.3 ± 0.8 pc) |
Absolute magnitude (MV) | +0.46 [6] |
Details | |
Mass | 2.4 [2] M☉ |
Radius | 4.8 [2] R☉ |
Luminosity | 54.20 [6] L☉ |
Surface gravity (log g) | 3.41 [7] cgs |
Temperature | 7,250 [4] K |
Metallicity [Fe/H] | −0.16 [4] dex |
Rotational velocity (v sin i) | 57 [8] km/s |
Age | 655 [2] Myr |
Other designations | |
Database references | |
SIMBAD | data |
28 Aquilae, abbreviated 28 Aql, is a star in the equatorial constellation of Aquila. 28 Aquilae is its Flamsteed designation though it also bears the Bayer designation A Aquilae, and the variable star designation V1208 Aquilae. It has an apparent visual magnitude is 5.5, [4] making this a faint star that requires dark suburban skies to view (according to the Bortle Dark-Sky Scale). The annual parallax shift of 9.6 mas means this star is located at a distance of approximately 340 light-years (100 parsecs) from Earth.
The spectrum of this star matches a stellar classification of F0 III. [4] Despite consistent spectral classifications as a giant star, [10] models show that it is just reaching the end of its main sequence lifetime at an age of 655 million years. [2]
The variability of 28 Aquilae was discovered by Michel Breger in 1969. It was revealed to be a Delta Scuti-type pulsating variable star with at least two periods of pulsation. The known periods have frequencies of 6.68 and 7.12 cycles per day. [11] The outer atmosphere has an effective temperature of 7,250 K, [4] which lies in the range of a yellow-white hued F-type star. [12]