HD 170384
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  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Corona Australis |
| Right ascension | 18h 31m 02.94877s[1] |
| Declination | −41° 54′ 49.8025″[1] |
| Apparent magnitude (V) | 6.02±0.01[2] |
| Characteristics | |
| Evolutionary stage | main sequence star[3] |
| Spectral type | A3 V[4] |
| B−V color index | +0.14[5] |
| Astrometry | |
| Radial velocity (Rv) | −11.4±0.4[6] km/s |
| Proper motion (μ) | RA: −3.406 mas/yr[1] Dec.: −31.578 mas/yr[1] |
| Parallax (π) | 14.2387±0.0341 mas[1] |
| Distance | 229.1 ± 0.5 ly (70.2 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.86[7] |
| Details | |
| Mass | 2.00[8] M☉ |
| Radius | 1.91±0.10[9] R☉ |
| Luminosity | 16.7+1.1 −1.0[3] L☉ |
| Surface gravity (log g) | 4.19+0.08 −0.07[10] cgs |
| Temperature | 8,694[11] K |
| Metallicity [Fe/H] | −0.01[12] dex |
| Rotation | 19.2 h[13] |
| Rotational velocity (v sin i) | 127±5[13] km/s |
| Age | 544[8] Myr |
| Other designations | |
| 11 G. Coronae Australis[14], CD−41°12871, CPD−41°8697, GC 25249, HD 170384, HIP 90759, HR 6931, SAO 229080[15] | |
| Database references | |
| SIMBAD | data |
HD 170384, also known as HR 6931 or rarely 11 G. Coronae Australis, is a solitary white-hued star located in the southern constellation Corona Australis. It has an apparent magnitude of 6.02,[2] making it barely visible to the naked eye, even under ideal conditions. The object is located relatively close at a distance of 229.1 light-years based on Gaia DR3 parallax measurements[1] and it is drifting closer with a heliocentric radial velocity of −11.4 km/s.[6] At its current distance, HD 170384's brightness is diminished by interstellar extinction of 0.28 magnitudes[16] and it has an absolute magnitude of +1.86.[7]
This object has a stellar classification of A3 V, indicating that it is an ordinary A-type main-sequence star. It has double the Sun's mass[8] and 1.91 times the radius of the Sun.[9] It radiates 16.7 times the luminosity of the Sun[3] from its photosphere at an effective temperature of 8,694 K.[11] HD 170384 has a near solar metallicity at [Fe/H] = −0.01 (97% solar)[12] and it is estimated to be 544 million years old,[8] having completed 45% of its main sequence lifetime.[3] Like many hot stars HD 170384 spins rapidly, having a projected rotational velocity of 127 km/s and an estimated rotation period of 19.2 hours.[13]
