HD 169853
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  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Corona Australis |
| Right ascension | 18h 28m 27.11405s[1] |
| Declination | −38° 59′ 44.4102″[1] |
| Apparent magnitude (V) | 5.62±0.01[2] |
| Characteristics | |
| Spectral type | A2m A2-F0[3] or A3 III[4] |
| B−V color index | +0.13[5] |
| Astrometry | |
| Radial velocity (Rv) | −21.3±1.2[6] km/s |
| Proper motion (μ) | RA: +0.096 mas/yr[1] Dec.: −41.093 mas/yr[1] |
| Parallax (π) | 8.3424±0.0673 mas[1] |
| Distance | 391 ± 3 ly (119.9 ± 1.0 pc) |
| Absolute magnitude (MV) | +0.13[7] |
| Details | |
| Mass | 2.09+0.39 −0.25[8] M☉ |
| Radius | 3.72±0.12[9] R☉ |
| Luminosity | 60.7+1.0 −1.1[1] L☉ |
| Surface gravity (log g) | 3.64[10] cgs |
| Temperature | 8,437±164[8] K |
| Metallicity [Fe/H] | −0.01[11] dex |
| Rotational velocity (v sin i) | 22.6±0.3[12] km/s |
| Age | 585+67 −66[1] Myr |
| Other designations | |
| 9 G. Coronae Australis[13], CD−39°12626, CPD−39°8093, GC 25185, HD 169853, HIP 90541, HR 6910, SAO 210197[14] | |
| Database references | |
| SIMBAD | data |
HD 169853, also known as HR 6910 or rarely 9 G. Coronae Australis, is a solitary star[15] located in the southern constellation Corona Australis. It is faintly visible to the naked eye as a white-hued point of light with an apparent magnitude of 5.62.[2] Gaia DR3 parallax measurements imply a distance of 391 light years,[1] and it is currently approaching the Solar System with a heliocentric radial velocity of −21.3 km/s.[6] At its current distance, HD 169853's brightness is diminished by 0.36 magnitudes due to extinction from interstellar dust[16] and it has an absolute magnitude of +0.13.[7]
HD 169853 has a stellar classification of A2mA2-F0,[3] indicating that it is an Am star with the calcium H lines of an A2 star and the metallic lines of an F0 star. Abt and Morell (1995) give a class of A3 III,[4] indicating that the object is instead an evolved A-type giant star with no chemical peculiarities. A paper published in late 1987 found that HD 169853 had an overabundance of silicon, manganese, strontium, and barium.[17]
The object has 2.09 times the mass of the Sun[8] and a slightly enlarged radius of 3.72 R☉.[9] It radiates 60.7 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 8,437 K.[8] It has a near solar metallicity at (Fe/H) = −0.01[11] and it is estimated to be 585 million years old, having completed 80% of its main sequence lifetime.[1] Like many chemically peculiar stars, HD 169853 rotates rather slowly, having a projected rotational velocity of 22.6 km/s.[12]
