HD 193664
Star in the constellation Draco
From Wikipedia, the free encyclopedia
HD 193664 is a star in the northern constellation of Draco. HD 193664 is its Henry Draper Catalogue designation. With an apparent magnitude of 5.93,[3] according to the Bortle Scale it is visible to the naked eye from suburban skies. Parallax measurements yield an estimated distance of 57 light years.[2] It has a relatively large proper motion of 0.558 arc seconds per year across the sky,[10] and is drifting closer to the Sun with a radial velocity of −4.7 km/s.[5]
 | |
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Draco[1] |
| Right ascension | 20h 17m 31.328s[2] |
| Declination | +66° 51′ 13.28″[2] |
| Apparent magnitude (V) | 5.93[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | G3 V[4] |
| U−B color index | +0.06[3] |
| B−V color index | +0.58[3] |
| Astrometry | |
| Radial velocity (Rv) | −4.7[5] km/s |
| Proper motion (μ) | RA: +468.684 mas/yr[2] Dec.: +297.589 mas/yr[2] |
| Parallax (π) | 57.2041±0.0208 mas[2] |
| Distance | 57.02 ± 0.02 ly (17.481 ± 0.006 pc) |
| Absolute magnitude (MV) | 4.69[1] |
| Details | |
| Mass | 1.04[6] M☉ |
| Radius | 1.03[7] R☉ |
| Luminosity | 1.1[6] L☉ |
| Surface gravity (log g) | 4.45[6] cgs |
| Temperature | 5,922[6] K |
| Metallicity [Fe/H] | −0.13[5] dex |
| Rotational velocity (v sin i) | 1.3[8] km/s |
| Age | 3.18[6] Gyr |
| Other designations | |
| BD+66°1281, GJ 788, HD 193664, HIP 100017, HR 7783, SAO 18796[9] | |
| Database references | |
| SIMBAD | data |
This star is considered a solar analog—meaning that it is photometrically analogous to the Sun—and it displays no significant variability.[11] It is a G-type main sequence star with a stellar classification of G3V.[4] Both the mass and radius of HD 193664 differ from those of the Sun by just a few percent, although it has a somewhat lower metallicity.[5] It may be around the same age as the Sun, being an estimated 3.2 billion years old.[6] The effective temperature of the stellar atmosphere is 5,922 K,[6] giving it the yellow-hued glow of a G-type star.[12]
HD 193664 has been examined for signs of an infrared excess that could indicate the presence of a circumstellar disk of dust, but none has been found (as of 2012).[13] This is member of the thin disk population of stars that lie near the galactic plane.[5]