HD 179791
Star in the constellation Aquila / From Wikipedia, the free encyclopedia
HD 179791 is suspected variable star[5] in the equatorial constellation of Aquila. It is a challenge to see with the naked eye even under good viewing conditions, having an apparent visual magnitude of 6.48.[2] The distance to HD 179791 can be estimated from its annual parallax shift of 5.3 mas,[1] which yields a value of 616 light years. It is moving further from the Earth with a heliocentric radial velocity of +16 km/s.[6] Astrometric measurements of the star show changes in motion that may indicate it is a member of a close binary system.[10]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquila |
Right ascension | 19h 13m 44.03146s[1] |
Declination | +05° 30′ 56.1725″[1] |
Apparent magnitude (V) | 6.48[2] |
Characteristics | |
Evolutionary stage | main sequence[3] |
Spectral type | A3 V[4] |
U−B color index | +0.10[2] |
B−V color index | +0.09[2] |
Variable type | suspected[5] |
Astrometry | |
Radial velocity (Rv) | +16.2[6] km/s |
Proper motion (μ) | RA: +6.819[1] mas/yr Dec.: −9.809[1] mas/yr |
Parallax (π) | 5.2966 ± 0.0569 mas[1] |
Distance | 616 ± 7 ly (189 ± 2 pc) |
Absolute magnitude (MV) | 0.66[7] |
Details | |
Mass | 2.55±0.15[3] M☉ |
Radius | 2.5[8] R☉ |
Luminosity | 65.8+21.0 −16.0[3] L☉ |
Temperature | 8912+166 −162[3] K |
Rotational velocity (v sin i) | 196[3] km/s |
Other designations | |
Database references | |
SIMBAD | data |
This is an A-type main-sequence star with a stellar classification of A3 V.[4] It is a suspected chemically peculiar star and formerly a candidate Lambda Boötis star.[11] The status as a Lambda Boötis star was reviewed and changed to non-member in 2015.[12] It is spinning rapidly with a projected rotational velocity of 196 km/s.[3] The star has 2.55[3] times the mass of the Sun and about 2.5[8] times the Sun's radius. It is radiating 66[3] times the Sun's luminosity from its photosphere at an effective temperature of 8,912 K.[3]