Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Corona Australis |
Right ascension | 18h 32m 21.33140s [1] |
Declination | −39° 42′ 14.4023″ [1] |
Apparent magnitude (V) | 5.16±0.01 [2] |
Characteristics | |
Spectral type | A3 V [3] or A3 Van [4] |
B−V color index | +0.08 [5] |
Astrometry | |
Radial velocity (Rv) | −6±4.2 [6] km/s |
Proper motion (μ) |
RA: +32.47
mas/
yr
[1] Dec.: −37.47 mas/ yr [1] |
Parallax (π) | 14.23 ± 0.23 mas [1] |
Distance | 229 ± 4
ly (70 ± 1 pc) |
Absolute magnitude (MV) | +0.93 [7] |
Details | |
Mass | 2.25 [8] M☉ |
Radius | 2.59±0.13 [9] R☉ |
Luminosity | 32.6 [10] L☉ |
Surface gravity (log g) | 3.96 [11] cgs |
Temperature | 8,938±161 [12] K |
Metallicity [Fe/H] | +0.24 [11] dex |
Rotational velocity (v sin i) | 177±1 [13] km/s |
Age | 480 [8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 170642, also designated as HR 6942 or rarely 13 G. Coronae Australis, is a single star [16] located in the southern constellation Corona Australis. It is faintly visible to the naked eye as a white hued star with an apparent magnitude of 5.16. [2] The object is located relatively close at a distance of 229 light years based on Hipparcos parallax measurements, [1] but it is approaching the Solar System with a somewhat constrained heliocentric radial velocity of −6 km/s. [6] At its current distance, HD 170642's brightness is diminished by 0.28 magnitudes due to interstellar dust. [17] It has an absolute magnitude of +0.93. [7]
This is an ordinary A-type main-sequence star with a stellar classification of A3 V. [3] Other sources include broad/nebulous absorption lines due to rapid rotation. [18] [4] It has 2.25 times the mass of the Sun and is estimated to be 480 million years old. [8] HD 170642 has a radius of 2.59 R☉. [9] When combined with an effective temperature of 8,938 K, [12] it radiates 32.6 times the luminosity of the Sun [10] from its photosphere. The star is metal enriched, having an iron abundance 74% greater than the Sun's. [11] Like many hot stars HD 170642 spins rapidly, having a projected rotational velocity of 177 km/s. [13]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Corona Australis |
Right ascension | 18h 32m 21.33140s [1] |
Declination | −39° 42′ 14.4023″ [1] |
Apparent magnitude (V) | 5.16±0.01 [2] |
Characteristics | |
Spectral type | A3 V [3] or A3 Van [4] |
B−V color index | +0.08 [5] |
Astrometry | |
Radial velocity (Rv) | −6±4.2 [6] km/s |
Proper motion (μ) |
RA: +32.47
mas/
yr
[1] Dec.: −37.47 mas/ yr [1] |
Parallax (π) | 14.23 ± 0.23 mas [1] |
Distance | 229 ± 4
ly (70 ± 1 pc) |
Absolute magnitude (MV) | +0.93 [7] |
Details | |
Mass | 2.25 [8] M☉ |
Radius | 2.59±0.13 [9] R☉ |
Luminosity | 32.6 [10] L☉ |
Surface gravity (log g) | 3.96 [11] cgs |
Temperature | 8,938±161 [12] K |
Metallicity [Fe/H] | +0.24 [11] dex |
Rotational velocity (v sin i) | 177±1 [13] km/s |
Age | 480 [8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 170642, also designated as HR 6942 or rarely 13 G. Coronae Australis, is a single star [16] located in the southern constellation Corona Australis. It is faintly visible to the naked eye as a white hued star with an apparent magnitude of 5.16. [2] The object is located relatively close at a distance of 229 light years based on Hipparcos parallax measurements, [1] but it is approaching the Solar System with a somewhat constrained heliocentric radial velocity of −6 km/s. [6] At its current distance, HD 170642's brightness is diminished by 0.28 magnitudes due to interstellar dust. [17] It has an absolute magnitude of +0.93. [7]
This is an ordinary A-type main-sequence star with a stellar classification of A3 V. [3] Other sources include broad/nebulous absorption lines due to rapid rotation. [18] [4] It has 2.25 times the mass of the Sun and is estimated to be 480 million years old. [8] HD 170642 has a radius of 2.59 R☉. [9] When combined with an effective temperature of 8,938 K, [12] it radiates 32.6 times the luminosity of the Sun [10] from its photosphere. The star is metal enriched, having an iron abundance 74% greater than the Sun's. [11] Like many hot stars HD 170642 spins rapidly, having a projected rotational velocity of 177 km/s. [13]