Gamma Coronae Australis

γ Coronae Australis
	Location of γ Coronae Australis (circled)
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Corona Australis
Right ascension	19h 06m 25.11014s
Declination	−37° 03′ 48.3901″
Apparent magnitude (V)	4.20
Characteristics
Spectral type	F8V + F8V
U−B color index	+0.51
B−V color index	+0.01
Astrometry
Radial velocity (Rv)	−51.60±0.3 km/s
Proper motion (μ)	RA: 96.74±1.05 mas/yr ; Dec.: −281.71±0.58 mas/yr
Parallax (π)	57.79±0.75 mas
Distance	56.4 ± 0.7 ly ; (17.3 ± 0.2 pc)
Absolute magnitude (MV)	3.73 / 3.80
Orbit
Period (P)	121.76 yr
Semi-major axis (a)	1.896″
Eccentricity (e)	0.320
Inclination (i)	149.6°
Longitude of the node (Ω)	50.3°
Periastron epoch (T)	2000.64
Argument of periastron (ω); (secondary)	349.0°
Details
γ CrA A
Mass	1.15 M☉
Radius	1.47 R☉
Surface gravity (log g)	4.17 cgs
Temperature	6,090 K
Metallicity [Fe/H]	−0.07 dex
Age	5 Gyr
γ CrA B
Mass	1.14 M☉
Radius	1.42 R☉
Surface gravity (log g)	4.19 cgs
Temperature	6,100 K
Metallicity [Fe/H]	−0.07 dex
Age	5 Gyr
Other designations
	γ CrA, CD−37°13048, HIP 93825, SAO 210928, CCDM J19064-3704
	γ CrA A: HD 177474, HR 7226
	γ CrA B: HD 177475, HR 7227
Database references
SIMBAD	γ CrA
	γ CrA A
	γ CrA B

Gamma Coronae Australis (γ CrA), is a binary star located in the constellation Corona Australis. The system has a combined apparent visual magnitude of 4.20, making it faintly visible to the naked eye. It is located 56.4 light-years (17.3 parsecs) from the Sun, based on its parallax. Gamma Coronae Australis is a member of the Milky Way's thin disk.

The system is a visual binary, where the orbit is calculated from observations of one star orbiting the other. The primary, Gamma Coronae Australis A, is a late F-type main-sequence star with an effective temperature of 6,090 K. It has an absolute an absolute magnitude of +3.73, and a mass of 1.15 solar masses. The secondary, Gamma Coronae Australis B, is also F-type. With an effective temperature of 6,100 K, an absolute magnitude of +3.80, and a mass of 1.14 solar masses, the companion is almost identical to the primary. Gamma Coronae Australis has been known to be a binary for a long time, and its two components have been given Henry Draper Catalogue designations of HD 177474 and HD 177475, respectively. The two stars are separated by 1.896″ and orbit each other every 121.76 years.