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Short description: Star in the constellation Andromeda
HD 166
Observation data
Equinox J2000.0]] (ICRS)
|
| Constellation
|
Andromeda
|
| Right ascension
|
00h 06m 36.7841s[1]
|
| Declination
|
+29° 01′ 17.4103″[1]
|
| Apparent magnitude (V)
|
6.13 – 6.17[2]
|
| Characteristics
|
| Spectral type
|
K0Ve[2][3]
|
| U−B color index
|
+0.30[4]
|
| B−V color index
|
+0.755[4]
|
| Variable type
|
BY Dra[2]
|
| Astrometry |
|---|
|
|---|
| Radial velocity (Rv) | −6.9±0.2[3] km/s |
| Proper motion (μ) | RA: 380.092±0.060[1] mas/yr
Dec.: −177.573±0.037[1] mas/yr |
| Parallax (π) | 72.5764 ± 0.0498[1] mas |
| Distance | 44.94 ± 0.03 ly
(13.779 ± 0.009 pc) |
| Absolute magnitude (MV) | 5.41[5] |
|
|---|
| Details |
|---|
|
|---|
| Mass | 0.889[6] M☉ |
| Radius | 0.9172±0.0090[6] R☉ |
| Luminosity | 0.6078±0.0099[6] L☉ |
| Surface gravity (log g) | 4.49±0.09[7] cgs |
| Temperature | 5509±34[7] K |
| Metallicity [Fe/H] | 0.00±0.03[7] dex |
| Rotation | 6.23±0.01 days[8] |
| Rotational velocity (v sin i) | 4.1 [8] km/s |
| Age | 78±28[7] Myr |
|
|---|
| Other designations |
|---|
BD+28°4704, GC 95, GSC 01735-02532, GSC 01735-00927, Gliese 5, HD 166, HIP 544, HR 8, SAO 73743, PPM 89410, NSV 33 |
| 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, varying between magnitudes 6.13 and 6.18 with a 6.23 days periodicity.[2] It appears within one degree of the star Alpha Andromedae[9] and is a member of the Hercules-Lyra association moving group.[3] It also happens to be less than 2 degrees from right ascension 00h 00m.
Star characteristics
HD 166 is a K-type main sequence star, cooler and dimmer than the Sun, and has a stellar classification of K0Ve[2] where the e suffix indicates the presence of emission lines in the spectrum. The star has a proper motion of 0.422 arcseconds per year in a direction 114.1° from north. It has an estimated visual luminosity of 61% of the Sun,[6] and is emitting like a blackbody with an effective temperature of 5,327K.[7] It has a diameter that is about 90% the size of the Sun[6] and a radial velocity of −6.9 km/s.[3] Age estimates range from as low as 78 million years old based on its chromospheric activity,[7] up to 9.6 billion years based on a comparison with theoretical evolutionary tracks.[6] X-ray emission has been detected from this star, with an estimated luminosity of 8.5×1028 erg s−1.[10]
An infrared excess has been detected around HD 166, most likely indicating the presence of a circumstellar disk at a radius of 7.5 AU. The temperature of this dust is 90 K.[11]
Variability
It has been found that the periodicity in the photometric variability of HD 166 is coincident with the rotation period.[8] This leads to its classification as a BY Draconis variable, where brightness variations are caused by the presence of large starspots on the surface and by chromospheric activity.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 "V439 And database entry". Combined General Catalog of Variable Stars. CDS. http://webviz.u-strasbg.fr/viz-bin/VizieR-S?V*%20V0439%20And.
- ↑ 3.0 3.1 3.2 3.3 López-Santiago, J.; Montes, D.; Crespo-Chacón, I.; Fernández-Figueroa, M. J. (2006). "The Nearest Young Moving Groups". The Astrophysical Journal 643 (2): 1160–1165. doi:10.1086/503183. Bibcode: 2006ApJ...643.1160L.
- ↑ 4.0 4.1 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD: 0, Bibcode: 1986EgUBV........0M
- ↑ Holmberg, J. et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics 501 (3): 941–947, doi:10.1051/0004-6361/200811191, Bibcode: 2009A&A...501..941H.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 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, doi:10.1088/0004-637X/771/1/40, Bibcode: 2013ApJ...771...40B.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Rich, Evan A.; Wisniewski, John P.; McElwain, Michael W.; Hashimoto, Jun; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Okamoto, Yoshiko K.; Abe, Lyu et al. (2017). "The fundamental stellar parameters of FGK stars in the SEEDS survey Norman, OK 73071, USA". Monthly Notices of the Royal Astronomical Society 472 (2): 1736. doi:10.1093/mnras/stx2051. Bibcode: 2017MNRAS.472.1736R.
- ↑ 8.0 8.1 8.2 Gaidos (2000). "Spectroscopy and Photometry of Nearby Young Solar Analogs". The Astronomical Journal 120 (2): 1006–1013. doi:10.1086/301488. Bibcode: 2000AJ....120.1006G.
- ↑ Autostar Suite Astronomer Edition. CD-ROM. Meade, April 2006.
- ↑ 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
- ↑ Eiroa, C. et al. (July 2013). "DUst around NEarby Stars. The survey observational results". Astronomy & Astrophysics 555: A11. doi:10.1051/0004-6361/201321050. Bibcode: 2013A&A...555A..11E.
External links
 | Original source: https://en.wikipedia.org/wiki/HD 166. Read more |
