45 Aquilae

45 Aquilae
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 19h 40m 43.31912s[1]
Declination –00° 37′ 16.3868″[1]
Apparent magnitude (V) 5.656[2] (5.9 + 7.6)[3]
Characteristics
Spectral type A3 IV[4]
U−B color index +0.09[2]
B−V color index +0.11[2]
Astrometry
Radial velocity (Rv)-46[5] km/s
Proper motion (μ) RA: +15.683[1] mas/yr
Dec.: +5.323[1] mas/yr
Parallax (π)9.3151 ± 0.1561 mas[1]
Distance350 ± 6 ly
(107 ± 2 pc)
Absolute magnitude (MV)0.49[6]
Orbit[7]
Primary5 Aql Aa
Companion5 Aql Ab
Period (P)20.31 ± 0.17 yr
Semi-major axis (a)0.0850 ± 0.0020″
Eccentricity (e)0.054 ± 0.047
Inclination (i)158.3 ± 7.9°
Longitude of the node (Ω)202.0 ± 15.0°
Periastron epoch (T)1996.06 ± 0.92
Argument of periastron (ω)
(secondary)		346.0 ± 25.0°
Details
45 Aql Aa
Mass2.63±0.10[8] M☉
Luminosity75.8+13.8
−11.7[8] L☉
Temperature9,016+167
−165[8] K
Rotational velocity (v sin i)75[8] km/s
Other designations
45 Aql, BD−00° 3813, FK5 3573, HD 185762, HIP 96807, HR 7480, SAO 14367, WDS J19407-0037[9]
Database references
SIMBADdata

45 Aquilae, abbreviated 45 Aql, is a triple star system in the equatorial constellation of Aquila. 45 Aquilae is its Flamsteed designation. It is located 350 light-years (110 parsecs) away from Earth, give or take a 6 light-year margin of error, and has a combined apparent visual magnitude of 5.7.[2] The system is moving closer to the Earth with a heliocentric radial velocity of -46 km/s.[5]

Based upon a stellar classification of A3 IV,[4] the primary component of this system is a subgiant star that is in the process of evolving away from the main sequence. The star has 2.6[8] times the mass of the Sun and is spinning with a projected rotational velocity of 75 km/s.[8] It has an orbiting companion with a period of 20.31 years and an eccentricity of 0.054. At an angular separation of 42.2 arcseconds from this pair is a 12.7 magnitude tertiary companion.[10]

  1. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference aass34_1 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Malkov2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference aj74_375 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference gcrv1953 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference aj140_3_735 was invoked but never defined (see the help page).
  8. ^ a b c d e f Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference mnras389_2_869 was invoked but never defined (see the help page).