Star in the constellation Cassiopeia
HD 15558 Observation dataEpoch J2000.0 Equinox J2000.0 Constellation Cassiopeia [ 1] Right ascension 02h 32m 42.537s [ 2] Declination 61° 27′ 21.57″[ 2] Apparent magnitude (V)7.87[ 3] Characteristics Spectral type O4.5III(f) [ 4] (O5.5III(f) + O7V[ 5] U−Bcolor index −0.55[ 3] B−Vcolor index +0.43[ 3] V−Rcolor index +0.38[ 3] R−Icolor index +0.40[ 3] J−Hcolor index +0.18[ 3] Astrometry Radial velocity (Rv )± 1.50[ 6] km/s Proper motion (μ)RA: −0.478[ 2] mas /yr Dec.: −0.849[ 2] mas /yr Parallax (π)0.5764± 0.0662 mas [ 2] Distance approx. 5,700 ly pc ) Absolute magnitude (MV )−0.79[ 1] Orbit Period (P)442 days[ 5] [ 5] yr ) Semi-major axis (a)726 R ☉ [ 5] Eccentricity (e)± 0.07[ 5] Argument of periastron (ω)120[ 5] Details Mass ± 51[ 5] M ☉ Radius 16.4[ 7] R ☉ Luminosity ~660,000[ 5] L ☉ Surface gravity (log g )3.7[ 7] cgs Temperature 39,500[ 7] K Age 0.7-3[ 5] [ 8] Myr secondary Mass ± 11[ 5] M ☉ Radius 5.6[ 7] R ☉ Other designations HD 15558,HIP 11832,SAO 12326,IDS 02251+6101,TYC 4046-44-1,UBV 2530,GCRV 1424,2MASS J02324253+6127215,WDS J02327+6127,PPM 13720,BD +60°502,GSC 04046-00044,CCDM J02327+6127,IC 1805 148Database references SIMBAD data
HD 15558 in the clusterIC 1805 HD 15558 (HIP 11832 ) is a massive O-typemultiple star system inCassiopeia and is specifically in our galaxy'sHeart Nebula in theopen cluster IC 1805 . The primary is a very massive star with 152 M ☉ and 660,000 L ☉
Physical characteristics [ edit ] HD 15558 A is a spectroscopic binary system containing at least two massive luminous class O stars. The primary is anO4.5 giant star with a surfacetemperature over 46,800K . It has a mass of 152M ☉ L ☉ Milky Way Galaxy. The star loses 1.5×10−5 M ☉ [ 8] O7V star. It has a mass of 46M ☉ [ 5]
TheWashington Double Star Catalog lists 11 companions within onearc minute of HD 15558 A, all fainter than 10th magnitude. In addition, it lists component E just over one arc minute away; it is another hot massive star, the 9th magnitude BD+60°501 with a spectral type of O7 V(n)((f))z.[ 4] [ 9]
^a b 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 . ^a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023)."Gaia Data Release 3. Summary of the content and survey properties" .Astronomy and Astrophysics .674 : A1.arXiv :2208.00211 Bibcode :2023A&A...674A...1G .doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source atVizieR .^a b c d e f Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system".CDS/ADC Collection of Electronic Catalogues .2237 .Bibcode :2002yCat.2237....0D . ^a b Sota, A.; Mainz Apellantiz, J.; Morrell, N.L; Barba, R.H; Walborn, N.R; et al. (2014). "The Galactic O-star spectroscopic survey (GOSSS). II. Bright southern stars".The Astrophysical Journal Supplement .211 (1): 10.arXiv :1312.6222 Bibcode :2014ApJS..211...10S .doi :10.1088/0067-0049/211/1/10 .S2CID 118847528 . ^a b c d e f g h i j k De Becker, M.; Rauw, G.; Manfroid, J.; Eenens, P. (2006)."Early-type stars in the young open cluster IC 1805. II. The probably single stars HD 15570 and HD 15629, and the massive binary/triple system HD 15558" .Astronomy & Astrophysics .456 (3): 1121.arXiv :astro-ph/0606379 Bibcode :2006A&A...456.1121D .doi :10.1051/0004-6361:20065300 .S2CID 16519684 . [permanent dead link ^ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits".Astronomy & Astrophysics .424 (2):727– 732.arXiv :astro-ph/0406573 Bibcode :2004A&A...424..727P .doi :10.1051/0004-6361:20041213 .S2CID 119387088 . ^a b c d Hillwig, T. C.; Gies, D. R.; Huang, W.; McSwain, M. V.; Wingert, D. W. (2006). "Binary and Multiple O-Type Stars in the Cassiopeia OB6 Association".The Astrophysical Journal .639 (2):1069– 1080.arXiv :astro-ph/0512407 Bibcode :2006ApJ...639.1069H .doi :10.1086/499771 .S2CID 119451956 . ^a b Garmany, C. D.; Massey, P. (1981)."HD 15558 - an extremely luminous O-type binary star" .Publications of the Astronomical Society of the Pacific .93 : 500.Bibcode :1981PASP...93..500G .doi :10.1086/130866 S2CID 121457874 . ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001)."The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog" .The Astronomical Journal .122 (6): 3466.Bibcode :2001AJ....122.3466M .doi :10.1086/323920
