Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Corona Australis |
Right ascension | 18h 31m 56.22382s [1] |
Declination | −43° 30′ 26.5714″ [1] |
Apparent magnitude (V) | 5.69±0.01 [2] |
Characteristics | |
Spectral type | K2 III [3] |
B−V color index | +1.34 [4] |
Astrometry | |
Radial velocity (Rv) | 7.2±0.4 [5] km/s |
Proper motion (μ) |
RA: −1.328
mas/
yr
[1] Dec.: −8.795 mas/ yr [1] |
Parallax (π) | 2.1538 ± 0.1596 mas [1] |
Distance | 1,500 ± 100
ly (460 ± 30 pc) |
Absolute magnitude (MV) | −1.90 [6] |
Details | |
Mass | 1.55 [7] M☉ |
Radius | 78.6±4.1 [8] R☉ |
Luminosity | 934 [9] L☉ |
Surface gravity (log g) | 0.96 [10] cgs |
Temperature | 4,474±122 [11] K |
Metallicity [Fe/H] | −0.49 [7] dex |
Rotational velocity (v sin i) | 6.5±1 [12] km/s |
Other designations | |
Database references | |
SIMBAD | data |
HD 170521, also known as HR 6937 or rarely 12 G. Coronae Australis, is a solitary star [15] located in the southern constellation Corona Australis. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.69. [2] The object is located relatively far at a distance of approximately 1,500 light years based on Gaia DR3 parallax measurements, [1] and it is receding with a heliocentric radial velocity of 7.2 km/s. [5] At its current distance, HD 170521's brightness is heavily diminished by 0.46 magnitudes due to extinction from interstellar dust [16] and it has an absolute magnitude of −1.90. [6]
HD 170521 has a stellar classification of K2 III, [3] indicating that it is an evolved red giant. It has 1.55 times the mass of the Sun [7] but it has expanded to 78.6 times the Sun's radius. [8] The object radiates 934 times the luminosity of the Sun [9] from its enlarged photosphere at an effective temperature of 4,474 K. [11] HD 170521 is metal deficient with an iron abundance only 32.4% that of the Sun (Fe/H) = −0.49 [7] and it spins modestly with a projected rotational velocity of 6.5 km/s. [12]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Corona Australis |
Right ascension | 18h 31m 56.22382s [1] |
Declination | −43° 30′ 26.5714″ [1] |
Apparent magnitude (V) | 5.69±0.01 [2] |
Characteristics | |
Spectral type | K2 III [3] |
B−V color index | +1.34 [4] |
Astrometry | |
Radial velocity (Rv) | 7.2±0.4 [5] km/s |
Proper motion (μ) |
RA: −1.328
mas/
yr
[1] Dec.: −8.795 mas/ yr [1] |
Parallax (π) | 2.1538 ± 0.1596 mas [1] |
Distance | 1,500 ± 100
ly (460 ± 30 pc) |
Absolute magnitude (MV) | −1.90 [6] |
Details | |
Mass | 1.55 [7] M☉ |
Radius | 78.6±4.1 [8] R☉ |
Luminosity | 934 [9] L☉ |
Surface gravity (log g) | 0.96 [10] cgs |
Temperature | 4,474±122 [11] K |
Metallicity [Fe/H] | −0.49 [7] dex |
Rotational velocity (v sin i) | 6.5±1 [12] km/s |
Other designations | |
Database references | |
SIMBAD | data |
HD 170521, also known as HR 6937 or rarely 12 G. Coronae Australis, is a solitary star [15] located in the southern constellation Corona Australis. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.69. [2] The object is located relatively far at a distance of approximately 1,500 light years based on Gaia DR3 parallax measurements, [1] and it is receding with a heliocentric radial velocity of 7.2 km/s. [5] At its current distance, HD 170521's brightness is heavily diminished by 0.46 magnitudes due to extinction from interstellar dust [16] and it has an absolute magnitude of −1.90. [6]
HD 170521 has a stellar classification of K2 III, [3] indicating that it is an evolved red giant. It has 1.55 times the mass of the Sun [7] but it has expanded to 78.6 times the Sun's radius. [8] The object radiates 934 times the luminosity of the Sun [9] from its enlarged photosphere at an effective temperature of 4,474 K. [11] HD 170521 is metal deficient with an iron abundance only 32.4% that of the Sun (Fe/H) = −0.49 [7] and it spins modestly with a projected rotational velocity of 6.5 km/s. [12]