HD 166

Last updated
HD 166
V439AndLightCurve.png
A light curve for V439 Andromedae, plotted from TESS data, [1] with the 6.23 day rotation period shown in red,
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Andromeda
Right ascension 00h 06m 36.7841s [2]
Declination +29° 01′ 17.4103″ [2]
Apparent magnitude  (V)6.13 – 6.17 [3]
Characteristics
Spectral type K0Ve [3] [4]
U−B color index +0.30 [5]
B−V color index +0.755 [5]
Variable type BY Dra [3]
Astrometry
Radial velocity (Rv)−6.9±0.2 [4]  km/s
Proper motion (μ)RA: 380.092±0.060 [2]   mas/yr
Dec.: −177.573±0.037 [2]   mas/yr
Parallax (π)72.5764 ± 0.0498  mas [2]
Distance 44.94 ± 0.03  ly
(13.779 ± 0.009  pc)
Absolute magnitude  (MV)5.41 [6]
Details
Mass 0.889 [7]   M☉
Radius 0.9172±0.0090 [7]   R☉
Luminosity 0.6078±0.0099 [7]   L☉
Surface gravity (log g)4.49±0.09 [8]   cgs
Temperature 5509±34 [8]   K
Metallicity [Fe/H]0.00±0.03 [8]   dex
Rotation 6.23±0.01 days [9]
Rotational velocity (v sin i)4.1 [9]  km/s
Age 78±28 [8]   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. [3] It appears within one degree of the star Alpha Andromedae [10] and is a member of the Hercules-Lyra association moving group. [4] It also happens to be less than 2 degrees from right ascension 00h 00m.

Contents

Star characteristics

HD 166 is a K-type main sequence star, cooler and dimmer than the Sun, and has a stellar classification of K0Ve [3] 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, [7] and is emitting like a blackbody with an effective temperature of 5,327K. [8] It has a diameter that is about 90% the size of the Sun [7] and a radial velocity of −6.9 km/s. [4] Age estimates range from as low as 78 million years old based on its chromospheric activity, [8] up to 9.6 billion years based on a comparison with theoretical evolutionary tracks. [7] X-ray emission has been detected from this star, with an estimated luminosity of 8.5×1028 erg s−1. [11]

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. [12]

Variability

It has been found that the periodicity in the photometric variability of HD 166 is coincident with the rotation period. [9] 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.

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<span class="mw-page-title-main">9 Ceti</span> Star in the constellation Cetus

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HD 219623 is a solitary star in the northern circumpolar constellation of Cassiopeia. HD 219623 is its Henry Draper Catalogue designation. It has an apparent visual magnitude of 5.59, which lies in the brightness range that is visible to the naked eye. According to the Bortle scale, it can be observed from dark suburban skies. Parallax measurements place it at an estimated distance of around 67.2 light years. It has a relatively high proper motion, advancing 262 mas per year across the celestial sphere.

c Ursae Majoris is the Bayer designation for a double-lined spectroscopic binary star system in the northern constellation of Ursa Major. It has an apparent visual magnitude of 5.18, which indicates that is visible to the naked eye. Parallax measurements yield an estimated distance of 66 light years from the Sun. The star is moving closer to the Earth with a heliocentric radial velocity of −14 km/s.

HD 46815 is a solitary star in the southern constellation Columba. It is faintly visible to the naked eye with an apparent magnitude of 5.4 and is estimated to be 408 light years away. However, it is receding with a heliocentric radial velocity of 32.2 km/s.

15 Delphini is a star in the equatorial constellation Delphinus. It has an apparent magnitude of 5.99, allowing it to be faintly seen with the naked eye. The star is relatively close at a distance of 99 light years but is receding with a heliocentric radial velocity of 4.1 km/s.

References

  1. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 26 August 2024.
  2. 1 2 3 4 5 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.
  3. 1 2 3 4 5 N. N. Samus; O. V. Durlevich; et al. "V439 And database entry". Combined General Catalog of Variable Stars (2017 ed.). CDS . Retrieved 2018-11-12.
  4. 1 2 3 4 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. arXiv: astro-ph/0601573 . Bibcode:2006ApJ...643.1160L. doi:10.1086/503183. S2CID   119520529.
  5. 1 2 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
  6. ↑ 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, arXiv: 0811.3982 , Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID   118577511.
  7. 1 2 3 4 5 6 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, S2CID   14911430.
  8. 1 2 3 4 5 6 Rich, Evan A.; Wisniewski, John P.; McElwain, Michael W.; Hashimoto, Jun; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Okamoto, Yoshiko K.; Abe, Lyu; Akiyama, Eiji; Brandner, Wolfgang; Brandt, Timothy D.; Cargile, Phillip; Carson, Joseph C.; Currie, Thayne M.; Egner, Sebastian; Feldt, Markus; Fukagawa, Misato; Goto, Miwa; Grady, Carol A.; Guyon, Olivier; Hayano, Yutaka; Hayashi, Masahiko; Hayashi, Saeko S.; Hebb, Leslie; Hełminiak, Krzysztof G.; Henning, Thomas; Hodapp, Klaus W.; Ishii, Miki; Iye, Masanori; 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. arXiv: 1708.02541 . Bibcode:2017MNRAS.472.1736R. doi: 10.1093/mnras/stx2051 . S2CID   58942857.
  9. 1 2 3 Gaidos; et al. (2000). "Spectroscopy and Photometry of Nearby Young Solar Analogs". The Astronomical Journal . 120 (2): 1006–1013. Bibcode:2000AJ....120.1006G. CiteSeerX   10.1.1.43.4478 . doi:10.1086/301488. S2CID   16930014.
  10. ↑ Autostar Suite Astronomer Edition. CD-ROM. Meade, April 2006.
  11. ↑ 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
  12. ↑ Eiroa, C.; et al. (July 2013). "DUst around NEarby Stars. The survey observational results". Astronomy & Astrophysics. 555: A11. arXiv: 1305.0155 . Bibcode:2013A&A...555A..11E. doi:10.1051/0004-6361/201321050. S2CID   377244.
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