71 Aquilae

71 Aquilae
	Template:Location mark; Location of 71 Aquilae (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Aquila
Right ascension	Template:RA
Declination	Template:DEC
Apparent magnitude (V)	4.33
Characteristics
Spectral type	G7.5 IIIa
U−B Template:Engvar	+0.68
B−V Template:Engvar	+0.96
R−I Template:Engvar	0.46
Astrometry
Radial velocity (Rv)	−5.6 km/s
Proper motion (μ)	RA: +14.84 mas/yr ; Dec.: −16.45 mas/yr
Parallax (π)	9.67±0.75 mas
Distance	Template:Rnd ± Template:Rnd ly ; (Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)	−1.03
Orbit
Period (P)	205.2 days
Semi-major axis (a)	Script error: No such module "val".
Eccentricity (e)	0.000
Inclination (i)	Script error: No such module "val".°
Longitude of the node (Ω)	Script error: No such module "val".°
Periastron epoch (T)	2423358.0 HJD
Argument of periastron (ω); (secondary)	0.00°
Details
primary
Mass	3.6 Template:Solar mass
Radius	16.7 Template:Solar radius
Luminosity	162 Template:Solar luminosity
Surface gravity (log g)	2.77 cgs
Temperature	5,046 K
Metallicity [Fe/H]	−0.03 dex
Rotational velocity (v sin i)	10 km/s
Age	347 Myr
secondary
Mass	0.88 Template:Solar mass
Metallicity [Fe/H]	{{{metal_fe2}}} dex
Other designations
	BD−01 4016, HD 196574, HIP 101847, HR 7884, SAO 144649.
Database references
SIMBAD	data

Script error: No such module "Check for unknown parameters".

71 Aquilae (abbreviated 71 Aql) is a binary star in the equatorial constellation of Aquila. 71 Aquilae is its Flamsteed designation though it also bears the Bayer designation l Aquilae. The apparent visual magnitude of the system is 4.33,^[2] making it bright enough to be viewed by the naked eye. It has an annual parallax shift of 9.67 mas,^[1] which equates to a physical distance of Script error: No such module "convert". from Earth, give or take a 30 light-year margin of error. At this distance, the brightness of the system is diminished by 0.065 in visual magnitude from extinction caused by interstellar gas and dust.^[5]

This is a spectroscopic binary system where the presence of an orbiting companion is revealed by shifts in the spectral lines caused by the Doppler effect. The primary component is a giant star with a stellar classification of G7.5 IIIa and is listed as a standard star for that class.^[3] The secondary is following a circular orbit with a period of 205.2 days.^[6]

References

Script error: No such module "Check for unknown parameters".

Observation data Epoch J2000 Equinox J2000
Template:Location mark Location of 71 Aquilae (circled)
Constellation	Aquila
Right ascension	Template:RA^[1]
Declination	Template:DEC^[1]
Apparent magnitude (V)	4.33^[2]
Characteristics
Spectral type	G7.5 IIIa^[3]
U−B Template:Engvar	+0.68^[2]
B−V Template:Engvar	+0.96^[2]
R−I Template:Engvar	0.46
Astrometry

Radial velocity (R_v)	−5.6^[4] km/s
Proper motion (μ)	RA: +14.84^[1] mas/yr Dec.: −16.45^[1] mas/yr
Parallax (π)	9.67±0.75 mas^[1]
Distance	Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc)
Absolute magnitude (M_V)	−1.03^[5]

Orbit^[6]
Period (P)	205.2 days
Semi-major axis (a)	Script error: No such module "val".
Eccentricity (e)	0.000
Inclination (i)	Script error: No such module "val".°
Longitude of the node (Ω)	Script error: No such module "val".°
Periastron epoch (T)	2423358.0 HJD
Argument of periastron (ω) (secondary)	0.00°
Details
primary
Mass	3.6^[7] Template:Solar mass
Radius	16.7^[8] Template:Solar radius
Luminosity	162^[8] Template:Solar luminosity
Surface gravity (log g)	2.77^[8] cgs
Temperature	5,046^[8] K
Metallicity [Fe/H]	−0.03^[8] dex
Rotational velocity (v sin i)	10^[9] km/s
Age	347^[10] Myr
secondary
Mass	0.88^[7] Template:Solar mass
Metallicity [Fe/H]	{{{metal_fe2}}} dex
Other designations
BD−01 4016, HD 196574, HIP 101847, HR 7884, SAO 144649.^[11]
Database references
SIMBAD	data