HD 221776

Double star in the constellation of Andromeda

HD 221776
Observation data Epoch J2000 Equinox J2000
Constellation	Andromeda
Right ascension	23^h 34^m 46.7420^s^[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 (R_v)	−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]
Distance	810 ± 20 ly (248 ± 5 pc)
Absolute magnitude (M_V)	−0.68^[2]

Details

Radius	3.43×10⁷^[5] km
Luminosity	451^[5] `L`_☉
Temperature	3,800^[5] K

Other designations
BD+37° 4866, HD 221776, HIP 116365, HR 8950, SAO 73351.
Database references
SIMBAD	data
Database references
SIMBAD	data

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]

References

^ ^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.
^ ^a ^b ^c ^d ^e Jasniewicz, G.; et al. (February 1999), "Late-type giants with infrared excess. I. Lithium abundances", Astronomy and Astrophysics, 342: 831–838, Bibcode:1999A&A...342..831J
^ Guetter, H. H.; Hewitt, A. V. (June 1984), "Photoelectric UBV photometry for 317 PZT and VZT stars", Publications of the Astronomical Society of the Pacific, 96: 441–443, Bibcode:1984PASP...96..441G, doi:10.1086/131362
^ Famaey, B.; et al. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165–186. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
^ ^a ^b ^c ^d Kim, Sungsoo S.; et al. (April 2001), "Extent of Excess Far-Infrared Emission around Luminosity Class III Stars", The Astrophysical Journal, 550 (2): 1000–1006, arXiv:astro-ph/0012001, Bibcode:2001ApJ...550.1000K, doi:10.1086/319803, S2CID 118903790
^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22
^ 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.

External links

Image HD 221776

Constellation of Andromeda

Stars

Bayer	α (Alpheratz) β (Mirach) γ (Almach) δ ε ζ η θ ι κ λ μ ν ξ (Adhil) ο π ρ σ τ υ (Titawin) φ χ ψ ω A b c υ Per (Nembus)
Flamsteed	2 3 4 5 6 7 8 9 10 11 12 13 14 (Veritate) 15 18 22 23 26 28 32 36 39 41 44 45 47 55 56 58 59 63 64 65 66 6 Per
Variable	R T U W Z RT RV RX SU SW TU TW WZ XZ AB AC AD AE AF AR BM BX CC CG CN DS DX EG ET EU FF GP GQ GX GR GY HH HN IW KK KX KZ LL LN LP LQ OP OS OU PX PY QO QR QV QX V385 V428 V439 V455 V529 V807
HR	1 40 56 78 104 122 134 178 275 282 283 289 379 410 483 687 746 748 8884 8925 8950 8962 8973 9011 9074 9075 9105
HD	16175 (Buna) 222155
Other	3XMM J004232.1+411314 ADS 48 HAT-P-6 (Sterrennacht) HAT-P-16 HAT-P-19 HAT-P-28 M31-RV KELT-1 NGC 44 NGC 82 NGC 84 NGC 91 NGC 162 NGC 464 Qatar-3 Qatar-4 PA-99-N2 WASP-1 WISE 0146+4234 WISE J0005+3737 WISE J004945.61+215120.0

Exoplanets	14 Andromedae b κ Andromedae b υ Andromedae b c d Gliese 15 Ab c HD 13931 b HD 16175 b HAT-P-6b HAT-P-32b WASP-1b WASP-33b Qatar-4b Qatar-5b

Star
clusters

NGC	206 272 752 956 7686
Other	Mayall II RBC EXT8

Nebulae

NGC	7662

Galaxies

Messier	32 110
NGC	5 11 13 19 20 21 27 39 43 48 49 51 67 68 69 70 71 72 74 76 79 80 81 83 85 86 90 93 94 96 97 108 109 112 140 149 160 169 181 183 184 214 218 226 228 229 233 243 252 258 260 262 280 304 317 389 393 404 425 431 477 512 513 523 528 529 531 536 542 561 605 620 668 679 687 700 703 704 705 708 709 710 712 714 717 721 732 753 759 801 812 834 891 906 910 911 912 913 920 937 980 995 996 999 1000 7640 7836
Numbered	I II III IV V VIII IX X XI XVIII XIX XXI
Other	3C 66A 3C 66B Andromeda Galaxy Arp 273 Donatiello I