Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquila |
Right ascension | 19h 29m 21.3603s[2] |
Declination | −07° 02′ 38.710″[2] |
Apparent magnitude (V) | 6.61[3] (6.08 - 6.86[4]) |
Characteristics | |
Spectral type | F5-G1 I-II[5] + B9.8V[6] |
U−B color index | 0.70[3] |
B−V color index | 1.10[3] |
Variable type | δ Cep[4] |
Astrometry | |
Radial velocity (Rv) | -6.5[2] km/s |
Proper motion (μ) | RA: -0.99[2] mas/yr Dec.: -9.14[2] mas/yr |
Parallax (π) | 3.63 ± 0.96 mas[2] |
Distance | 614[6] pc |
Absolute magnitude (MV) | −3.68[6] |
Orbit[7] | |
Period (P) | 1,856 |
Semi-major axis (a) | 1.311" (6.1 AU) |
Eccentricity (e) | 0.165 |
Inclination (i) | 74° |
Longitude of the node (Ω) | 190° |
Details | |
A | |
Mass | 5.7[6] M☉ |
Radius | 55[7] R☉ |
Luminosity | 2,570[6] L☉ |
Surface gravity (log g) | 1.3[8] cgs |
Temperature | 5,440-6,640[8] K |
Metallicity [Fe/H] | 0.17[9] dex |
B | |
Mass | 2.3[6] M☉ |
Radius | 2.1[7] R☉ |
Temperature | 9,300[7] K |
Other designations | |
Database references | |
SIMBAD | data |
U Aquilae is a binary star system in the constellation Aquila, Located approximately 614 parsecs (2,000 ly) away from Earth.
The primary star (component A) is a yellow supergiant with a radius of 55 R☉ and a luminosity of 2,570 L☉. The secondary (component B) is a blue main-sequence star, twice the mass of the sun and around thirty times more luminous. It is hotter than the primary star at 9,300 K, but much smaller and fainter. The two stars orbit every five years and their separation varies from five to seven astronomical units in a mildly eccentric orbit.
u Aql A is a classical Cepheid variable star ranging between magnitudes 6.08 and 6.86 over a period of 7.02 days. It is an evolved star which has exhausted its core hydrogen and is now fusing helium into carbon.[10]
Kiss
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