Delta Aquilae, Latinized from δ Aquilae, is a binary star system in the equatorial constellation of Aquila. It has an apparent visual magnitude of 3.4[2] and, based upon parallax measurements, is located at a distance of about 50.6 light-years (15.5 parsecs) from Earth.[1] It is drifting closer with a radial velocity of −30 km/s.[6] The system is predicted to come to within 25.4 ly (7.8 pc) of the Sun in around 335,000 years.[14]
Quick Facts Constellation, Right ascension ...
Delta Aquilae
Location of δ Aquilae (circled) near the center |
Observation data Epoch J2000 Equinox J2000 |
Constellation |
Aquila |
Right ascension |
19h 25m 29.90139s[1] |
Declination |
+03° 06′ 53.2061″[1] |
Apparent magnitude (V) |
3.365[2] |
Characteristics |
Spectral type |
F0 IV[3] + K[4] |
U−B color index |
+0.031[2] |
B−V color index |
+0.319[2] |
R−I color index |
+0.16 |
Variable type |
δ Sct[5] |
Astrometry |
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|
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Radial velocity (Rv) | −30.1[6] km/s |
Proper motion (μ) | RA: +254.54[1] mas/yr Dec.: +82.51[1] mas/yr |
Parallax (π) | 64.41 ± 1.00 mas[1] |
Distance | 50.6 ± 0.8 ly (15.5 ± 0.2 pc) |
Absolute magnitude (MV) | 2.46[7] |
|
Orbit[8] |
---|
Period (P) | 3.426 ± 0.006 yr |
Semi-major axis (a) | 0.0539 ± 0.0040″ |
Eccentricity (e) | 0.36 ± 0.07 |
Inclination (i) | 150 ± 11° |
Longitude of the node (Ω) | 337 ± 9° |
Periastron epoch (T) | 1,954.58 ± 0.13 |
Argument of periastron (ω) (secondary) | 191 ± 14° |
Details |
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δ Aql Aa |
---|
Mass | 1.65[4] M☉ |
Radius | 2.04[4] R☉ |
Luminosity | 6.8[9]–7.9[10] L☉ |
Surface gravity (log g) | 4.03[11] cgs |
Temperature | 7,016[7] K |
Metallicity [Fe/H] | −0.04[11] dex |
Rotational velocity (v sin i) | 87.3[12] km/s |
δ Aql Ab |
---|
Mass | 0.67[4] M☉ |
Radius | 0.61[4] R☉ |
Other designations |
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Al Mizān I, δ Aql, 30 Aql, BD+02° 3879, FK5 730, GJ 760, HD 182640, HIP 95501, HR 7377, SAO 124603, NLTT 47775 [13] |
Database references |
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SIMBAD | data |
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