12 Camelopardalis

Star in the constellation of Camelopardalis 250px 12 Camelopardalis (center) in optical light J2000.0 Camelopardalis 05 06 12.13609 +59 01 16.8261 6.08 giant K0 IIIe 1.112 0.009 RS CVn −1.92 0.27 −2.264 −26.949 4.6513 0.0706 −0.332 12 Cam A 1.1 23.08 0.75 1.34 212 4 12 Cam B 0.6 BM Cam 12 Cam +58°805 32357 23743 1623 25003 2480 05062+5900 J05061+5858B 12+Cam 12 Camelopardalis is a binary star in the northern circumpolar constellation of Camelopardalis, located 700 light years away from the Sun as determined from parallax measurements. It forms a double star with 11 Camelopardalis, which is only 3 arcminutes away. The system has the variable star designation BM Camelopardalis; 12 Camelopardalis is the Flamsteed designation. It is just visible to the naked eye, appearing as a dim, orange-hued star with an apparent visual magnitude of 6.08. The system is moving closer to the Earth with a heliocentric radial velocity of −2 km/s. thumb|left|A visual band light curve for BM Camelopardalis, adapted from Zboril and Messina (2009). The main plot shows the long-term variability, and the inset plot shows the variability due to the star's rotation. Abt et al. (1969) determined this to be a single-lined spectroscopic binary system and computed an orbital solution with a period of 80.17 days and an eccentricity of 0.35. However, what appeared to be an ellipticity effect with a period of 79.93 0.05 days was found, which was inconsistent with the computed orbit, and the lack of modulation of the amplitude did not fit with the large orbital eccentricity. Hall et al. (1995) made additional measurements, finding an orbital period of 80.9 days and an eccentricity that is statistically indistinguishable from zero. The visible component is an evolved giant star with a stellar classification of K0 IIIe, showing strong emission lines. Joel A. Eaton et al. discovered that the star's brightness varies, in 1980. It was given its variable star designation in 1981. It is an RS Canum Venaticorum variable and its brightness varies by 0.14 magnitudes with a period of 82.9 days due to starspots. The star is most likely rotating in synchronous manner with its orbital period. The magnetic activity has two overlapping cycles of 14.8 and 8.5 years, with the activity occurring at two latitudes. BM Cam emits X-rays and is the designated X-ray source 1H 0501+592. It has been detected by HEAO 1, the Einstein Observatory, and ROSAT. References 283927609195553792 12 Cam 2019-04-15 Keenan Philip C. McNeil Raymond C. The Perkins catalog of revised MK types for the cooler stars Astrophysical Journal Supplement Series 71 245 1989 . 1989ApJS...71..245K 10.1086/191373 Eaton J. A. Hall D. S. Henry G. W. Landis H. J. McFaul T. G. Renner T. R. 12 Camelopardalis: a new variable star Information Bulletin on Variable Stars December 1980 1902 1 1980IBVS.1902....1E https://ibvs.konkoly.hu/pub/ibvs/1901/1902.pdf 29 December 2024 Kholopov P. N. Samus N. N. Kukarkina N. P. Medvedeva G. I. Perova N. B. 66th Name-List of Variable Stars Information Bulletin on Variable Stars November 1981 2042 1 1981IBVS.2042....1K https://ibvs.konkoly.hu/pub/ibvs/2001/2042.pdf 29 December 2024 Ultraviolet Emission Lines in BA and Non-BA Giants 1 Böhm-Vitense Erika Carpenter Kenneth G. Robinson Richard D. The Astrophysical Journal . 545 2 992–999 December 2000 10.1086/317850 2000ApJ...545..992B free . Wood K. S. Meekins J. F. Yentis D. J. Smathers H. W. McNutt D. P. Bleach R. D. The HEAO A-1 X-ray source catalog Astrophysical Journal Supplement Series Dec 1984 56 12 507–649 1984ApJS...56..507W 10.1086/190992 free Magnetic activity on 12 Cam and 29 Dra from long-term photometry Zboril M. Messina S. Astronomische Nachrichten . 330 4 377 April 2009 10.1002/asna.200811190 2009AN....330..377Z 12 Cam., Calcium emission in giant binaries. 1 Abt Helmut A. Dukes Robert J. Weaver W. Bruce Astrophysical Journal . 157 717 August 1969 10.1086/150108 1969ApJ...157..717A free A spectroscopic and photometric study of 12 BM Camelopardalis 1 Hall D. S. Fekelf C. Henry G. W. Eaton J. A. Barksdale W. S. Dadonas V. Eker Z. Kalv P. Chambliss C. R. Fried R. E. Fortier G. L. Landis H. J. Louth H. P. Powell H. D. McFaul T. G. Miles R. Nielsen P. Renner T. R. Robb S. P. Slauson D. M. Stelzer H. J. Wasson R. Wood J. E. Astronomical Journal . 109 3 1277–1288 March 1995 10.1086/117360 1995AJ....109.1277H free 1 Samus N. N. Kazarovets E. V. Durlevich O. V. Kireeva N. N. Pastukhova E. N. General Catalogue of Variable Stars 5.1 Astronomy Reports 2017 61 1 80–88 10.1134/S1063772917010085 2017ARep...61...80S 125853869 . XHIP: An extended hipparcos compilation Anderson E. Francis Ch. Astronomy Letters 38 5 331 2012 2012AstL...38..331A 10.1134/S1063773712050015 1108.4971 119257644 . Category:RS Canum Venaticorum variables Category:Astronomical X-ray sources Category:Spectroscopic binaries Category:Double stars Category:Camelopardalis Category:Durchmusterung objects Camelopardalis, 12 032357 023743 1623 Camelopardalis, BM Category:K0III stars