HD 166
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| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 06m 36.78s[2] |
| Declination | +29° 01′ 17.4″[2] |
| Apparent magnitude (V) | 6.13 |
| Characteristics | |
| Spectral type | G8V[3] |
| U−B color index | +0.33 |
| B−V color index | +0.75 |
| Variable type | BY Draconis variable [4] |
| Astrometry | |
| Radial velocity (Rv) | -8.2 km/s |
| Proper motion (μ) | RA: 380.98 ± 0.57[2] mas/yr Dec.: -178.68 ± 0.29[2] mas/yr |
| Parallax (π) | 73.15 ± 0.56[2] mas |
| Distance | 44.6 ± 0.3 ly (13.7 ± 0.1 pc) |
| Details | |
| Mass | 0.889[3] M☉ |
| Radius | 0.9172 ± 0.0090[3] R☉ |
| Luminosity | 0.6078 ± 0.0099[3] L☉ |
| Temperature | 5327 ± 39[3] K |
| Metallicity [Fe/H] | 0.08[3] dex |
| Rotation | 6.23 ± 0.01 days[5] |
| Age | 9.6[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 166 or V439 Andromedae (ADS 69 A) is a 6th magnitude star in the constellation Andromeda, approximately 45 light years away from Earth. It is a variable star of the BY Draconis type,[4] with a variation in brightness smaller than 0.2 magnitude. It is a dwarf star like our Sun, yet cooler and dimmer, having a stellar classification of spectral type G8V and a surface temperature of 5,327 kelvin.[3] It is within one degree of the star Alpha Andromedae.[6]
It is located at celestial (X,Y,Z) coordinates of 39.1, 1.13, 21.7 galactic (X,Y,Z) coordinates in ly: -14.1, 34.9, -24.1 and is found at right ascension and declination 0h6m36.75s, +29°1'17.6".
The star has a proper motion of 0.422 arcsec/yr (114.1° from north). It has an estimated visual luminosity of 61% of Sol. It has a diameter that is about 0.91 x Sol and has a radial velocity of -5.5 km/s. It is estimated to be about 200 million years old based on its chromospheric activity.[7] X-ray emission has been detected from this star, with an estimated luminosity of 8.5 × 1028 erg s–1.[8]
The habitable zone for an Earth-like planet would be about 0.77 A.U.s from the star.
References
- ↑ "Simbad Query Result". Simbad. Retrieved October 12, 2007.
- ↑ 2.0 2.1 2.2 2.3 2.4 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.Vizier catalog entry
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Boyajian, Tabetha S. et al. (July 2013), "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations", The Astrophysical Journal 771 (1): 40, arXiv:1306.2974, Bibcode:2013ApJ...771...40B, doi:10.1088/0004-637X/771/1/40.
- ↑ 4.0 4.1 Kazarovets et al. (2006-08-08). "The 78th Name-List of Variable Stars". The Information Bulletin on Variable Stars Number 5721. Konkoly Observatory. Retrieved 2010-03-01.
- ↑ Gaidos et al. (2000). "Spectroscopy and Photometry of Nearby Young Solar Analogs". The Astronomical Journal 120 (2): 1006–1013. Bibcode:2000AJ....120.1006G. doi:10.1086/301488.
- ↑ Autostar Suite Astronomer Edition. CD-ROM. Meade, April 2006.
- ↑ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal 687 (2): 1264–1293. arXiv:0807.1686. Bibcode:2008ApJ...687.1264M. doi:10.1086/591785.
- ↑ Micela, G.; Favata, F.; Sciortino, S. (October 1997), "HIPPARCOS distances of X-ray selected stars: implications on their nature as stellar population", Astronomy and Astrophysics 326: 221–227, Bibcode:1997A&A...326..221M
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