Back اچدی ۱۵۶۶۶۸ Persian HD 156668 Italian HD 156668 Latvian/Lettish HD 156668 Russian HD 156668 Swedish HD 156668 Chinese
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hercules[1] |
| Right ascension | 17h 17m 40.49053s[2] |
| Declination | +29° 13.6′ 38.0243″[2] |
| Apparent magnitude (V) | +8.424[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | K3 V[3] |
| B−V color index | 1.015[3] |
| Astrometry | |
| Radial velocity (Rv) | −9.427[5] km/s |
| Proper motion (μ) | RA: −72.481±0.016 mas/yr[6] Dec.: +216.849±0.019 mas/yr[6] |
| Parallax (π) | 41.1103±0.0169 mas[6] |
| Distance | 79.34 ± 0.03 ly (24.325 ± 0.010 pc) |
| Absolute magnitude (MV) | 6.480[3] |
| Details | |
| Mass | 0.772±0.020[3] M☉ |
| Radius | 0.720±0.013[3] R☉ |
| Luminosity | 0.230±0.018[3] L☉ |
| Surface gravity (log g) | 4.60±0.12[3] cgs |
| Temperature | 4,850±88[3] K |
| Metallicity [Fe/H] | +0.05±0.06[3] dex |
| Rotation | 51.5 days[3] |
| Rotational velocity (v sin i) | 0.50±1.0[3] km/s |
| Age | 8.6±4.8[3] Gyr |
| Other designations | |
| BD+29°2979, HD 156668, HIP 84607, SAO 84984, Wolf 646, 2MASS J17174049+2913378[7] | |
| Database references | |
| SIMBAD | data |
HD 156668 is a star in the northern constellation of Hercules constellation. With an apparent visual magnitude of 8.4[3] it is too faint to be viewed with the naked eye, but it can be seen with even a small telescope.[8] The distance to this object has been determined directly using the parallax technique, yielding a value of about 80 light-years (25 parsecs).[2]
This star has the stellar classification of a K2 dwarf, with approximately 77% of the mass of the Sun and about 72% of the Sun's diameter. While they are on the main sequence, lower mass stars like this generate energy much more slowly than the Sun. As a result, this star is radiating only 23% of the Sun's bolometric luminosity. HD 156668 is emitting this energy from its outer atmosphere at an effective temperature of around 4850 K,[3] giving it the cool orange glow of a K-type star.[9] It is slightly more enriched in iron compared to the Sun and is rotating at a leisurely rate of once every 51.5 days. Although much older than the Sun, this star is only middle-aged at about 8.6 billion years.[3]
The HD 156668 exhibits a stellar activity cycle with a period about 10 years.[10]
- ^ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
- ^ a b c Cite error: The named reference
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apj726_2_73was invoked but never defined (see the help page). - ^ Just, A.; Jahrei, H. (2008). "The main sequence from F to K stars of the solar neighbourhood in SDSS colours". Astronomische Nachrichten. 329 (8): 790. arXiv:0808.2111. Bibcode:2008AN....329..790J. doi:10.1002/asna.200811030.
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
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