HD 224635 and HD 224636

HD 224635 and HD 224636 is a pair of stars comprising a binary star system in the constellation Andromeda. They are located approximately 94 light years away^[7] and they orbit each other every 717 years.^[2]

HD 224635/HD 224636

Observation data Epoch J2000      Equinox J2000
Constellation	Andromeda
HD 224635
Right ascension	23h 59m 29.2915s[1]
Declination	+33° 43′ 25.8773″[1]
Apparent magnitude (V)	6.46[2]
HD 224636
Right ascension	23h 59m 29.2054s[3]
Declination	+33° 43′ 27.6539″[3]
Apparent magnitude (V)	6.72[2]
Characteristics
HD 224635
Spectral type	F8[4]
B−V color index	0.51[5]
HD 224636
Spectral type	G1[4]
B−V color index	0.55[5]
Astrometry
Radial velocity (Rv)	−7.90±0.2[6] km/s
Proper motion (μ)	RA: −59.68±0.65[7] mas/yr Dec.: −113.19±0.35[7] mas/yr
Parallax (π)	34.57 ± 0.51 mas[7]
Distance	94 ± 1 ly (28.9 ± 0.4 pc)
Details
Mass	1.19 + 1.13 [8] M☉
Luminosity	3.47[9] L☉
Temperature	6,072[10] K
Metallicity	-0.070[10]
Other designations
BD+32 4747, HIP 118281, SAO 73656, ADS 17149, WDS J23595+3343
HD 224635: HR 9074
HD 224636: HR 9075
Database references
SIMBAD	data
Database references
SIMBAD	data

The primary star is HD 224635, a magnitude 6.46^[2] star (making it visible by the naked eye under very favourable conditions) with a spectral type F8^[4] that is 1.19 times more massive than the Sun.^[8]

The secondary star is the slightly fainter HD 224636, with an apparent visual magnitude of 6.72,^[2] a spectral type G1,^[4] and 1.13 times more massive than the Sun.^[8]

References

1. 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. Malkov, O. Yu.; et al. (2012), "Dynamical Masses of a Selected Sample of Orbital Binaries", Astronomy & Astrophysics, 546: 5, Bibcode:2012A&A...546A..69M, doi:10.1051/0004-6361/201219774, A69
3. 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.
4. Struve, Otto; Franklin, K. L. (1955). "Spectrographic Observations of Visual Double Stars". The Astrophysical Journal. 121: 337. Bibcode:1955ApJ...121..337S. doi:10.1086/145993.
5. Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
6. de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
7. van Leeuwen, F. (November 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, S2CID 18759600.
8. Tokovinin, Andrei (2014). "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs". The Astronomical Journal. 147 (4): 14. arXiv:1401.6827. Bibcode:2014AJ....147...87T. doi:10.1088/0004-6256/147/4/87. S2CID 56066740. 87.
9. 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, S2CID 119257644.
10. Soubiran, Caroline; et al. (2016), "The PASTEL catalogue: 2016 version", Astronomy & Astrophysics, 591: A118, arXiv:1605.07384, Bibcode:2016A&A...591A.118S, doi:10.1051/0004-6361/201628497, S2CID 119258214.