HD 221776

HD 221776
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 34m 46.7420s[1]
Declination +38° 01′ 26.4016″[1]
Apparent magnitude (V) 6.18[2]
Characteristics
Spectral type K5III[2]
U−B color index +1.97[3]
B−V color index +1.586[2]
Astrometry
Radial velocity (Rv)−13.74±0.11[4] km/s
Proper motion (μ) RA: 10.272±0.114[1] mas/yr
Dec.: 11.738±0.106[1] mas/yr
Parallax (π)4.0297 ± 0.0838 mas[1]
Distance810 ± 20 ly
(248 ± 5 pc)
Absolute magnitude (MV)−0.68[2]
Details
Radius3.43×107[5] km
Luminosity451[5] L☉
Temperature3,800[5] K
Other designations
BD+37° 4866, HD 221776, HIP 116365, HR 8950, SAO 73351.
Database references
SIMBADdata
Database references
SIMBADdata

HD 221776 is a double star in the northern constellation of Andromeda. With an apparent visual magnitude of 6.18,[2] it is viewable by the naked eye user very favourable conditions. The most luminous component has a spectral classification K5III, meaning that it is an orange giant star that has evolved off the main sequence. An infrared excess has been detected around this star, indicating the star is associated with a cloud of dust particles.[5]

There is a magnitude 11.8 companion at angular separation of 19.8″ along a position angle of 329°, as of 2002;[6] however, its distance measured by parallax yields a much greater distance than the primary star.[7]

  1. ^ a b c d e 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.
  2. ^ a b c d e Cite error: The named reference aaa342_831 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference pasp96_441 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Famaey2005 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference apj550_2_1000 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  7. ^ 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.