Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Corona Australis |
Right ascension | 19h 06m 52.46439s [1] |
Declination | −37° 48′ 38.3734″ [1] |
Apparent magnitude (V) | 6.16 [2] |
Characteristics | |
Spectral type | G6 V [3] |
U−B color index | +0.27 [4] |
B−V color index | +0.70 [4] |
Astrometry | |
Radial velocity (Rv) | 60.9±0.8 [5] km/s |
Proper motion (μ) | RA: −187.700 mas/yr [1] Dec.: −367.009 mas/yr [1] |
Parallax (π) | 58.9860±0.0376 mas [1] |
Distance | 55.29 ± 0.04 ly (16.95 ± 0.01 pc) |
Absolute magnitude (MV) | +5.00 [6] |
Details | |
Mass | 0.99+0.03 −0.04 [7] M☉ |
Radius | 0.985±0.022 [8] R☉ |
Luminosity | 0.851±0.005 [1] L☉ |
Surface gravity (log g) | 4.44±0.03 [9] cgs |
Temperature | 5,627±19 [10] K |
Metallicity [Fe/H] | 0.08±0.01 [10] dex |
Rotational velocity (v sin i) | 3 [11] km/s |
Age | 4.58±1.51 [12] Gyr |
Other designations | |
42 G. Coronae Australis [13] , CD−37°13049, CPD−37°8466, GC 26283, GJ 744, HD 177565, HIP 93858, HR 7232, SAO 210937, LTT 7569 [14] | |
Database references | |
SIMBAD | data |
HD 177565 (HR 7232; LTT 7569; Gliese 744) is a yellow-hued star located in the southern constellation Corona Australis. It has an apparent magnitude of 6.16, [2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively close at a distance of 55.3 light-years based on Gaia DR3 parallax measurements, [1] but it is receding rapidly with a heliocentric radial velocity of 60.9 km/s . [5] At its current distance, HD 177565's brightness is diminished by interstellar extinction of 0.07 magnitudes [15] and it as an absolute magnitude of +5.00. [6] A 2017 multiplicity survey failed to detect any stellar companions around the star. [16]
HD 177565 has a stellar classification of G6 V, [3] indicating that it is an ordinary G-type main-sequence star like the Sun. The object has also be given a later class of G8 V (Houk 1982) [17] and one source lists it as a G5 subgiant. [18] It has 99% the mass of the Sun [7] and 98.5% the Sun's radius. [8] It radiates 85.1% the luminosity of the Sun [1] from its photosphere at an effective temperature of 5,627 K , [10] making it slightly cooler than the Sun. HD 177565 is slightly metal enriched with an iron abundance at [Fe/H] = +0.08 (120% solar) [10] and it is estimated to be 4.58 billion years old. [12] HD 177565 spins slightly faster than the Sun with a projected rotational velocity of 3 km/s [11] compared to the Sun's rotational velocity of 2 km/s.
In 2017, an exoplanet was discovered orbiting the star after observations of HARPS data. HD 177565 b is a hot Neptune that takes 44.5 days to revolve around its host star in a relatively circular orbit. [19]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥15.10+6.40 −6.05 M🜨 | 0.246±0.019 | 44.5+0.6 −0.3 | 0.059+0.172 −0.058 | — | ~4.1 [20] R🜨 |