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  V1357 Cyg  
000-BCJ-914 (1261 observations)  
Cygnus Sequence
19 58 21.68 +35 12 05.8  (299.59033 +35.20161) Search nearby
B1950.0 19 56 28.95 +35 03 54.8
Proper motion
RA: -3.37 +/- 0.75 mas/yDec: -7.15 +/- 0.86 mas/ySource: F. Van Leeuwen, 2007
Galactic coord. 71.335 +3.067
Other names

(Internal only)
1RXS J195821.9+351156 4U 1956+35 4U 1956+350
AAVSO 1954+34 BD+34 3815 Cyg X-1
HD 226868 HIP 98298 IOMC 2678000054
SAO 69181 SVS 1808 UCAC4 627-087910
X 19564+350    
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Variability type
Spectral type O9.7Iab+BH
Mag. range
8.72 - 8.93 V
Discoverer --
31 Aug 1972 (HJD 2441561.22) Ephemeris
Outburst --
Period 5.599824 d
Rise/eclipse dur. --
Some references may be clicked to view in new window. Roll over index number to view submission details.
1 Otero, Sebastian Alberto Microquasar. Black hole component. Gamma Ray emitter.
2 GCVS Team Cyg X-1. SB1. The epoch of the inferior conjunction of the optical component is given in the Table. Min II 8.88. The shape of the light curve varies; Min II sometimes are not observed. The periodicity in the light curve variations as well as in polarization changes is possible with P = 78.4d [J.C.Kemp, L.C.Herman, M.S.Barbour, AJ 83, 962-970, 1978., E.A.Karitskaya, Astron. Tsirk. N1088, 1979.]. Rapidly variable X-ray source in wide range up to 3 MeV characterized by the change of high and low states. Light and X-ray variation with P = 294d is also detected [R.K.Manchanda, ApSS 91, N2, 455, 1983., J.C.Kemp, IAU Circ N3780, 1983.]. Variable and flare radio source at 2695 and 8085 MHz.
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Click reference title/citation to view in new window. Roll over index number to view submission details.
1 Corral-Santana, J. M.; Casares, J.; Muņoz-Darias, T.; et al., 2016,
WATCHDOG: A Comprehensive All-sky Database of Galactic Black Hole X-ray
2 J. Alfonso-Garzon, A. Domingo, J.M. Mas-Hesse, A. Gimenez, 2012,
arXiv:1210.0821 [astro-ph.IM] (online info)
3 A Multiwavelength Study of Cygnus X-1: The First Mid-infrared Spectroscopic
Detection of Compact Jets
4 C. Koen, L. Eyer, 2002, MNRAS 331, 45 2002MNRAS.331...45K
5 E.N.Walker, MN 177, 63P, 1975. 1976MNRAS.177P..63W
6 V.M.Lyutyj, Perem. Zvezdy 18, N5, 417, 1972. 1972PZ.....18..417L
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Catalog Data
Information from selected catalogs obtained by cross-matching to 2 arc seconds using the CDS X-Match Service. These data may not be complete.
2MASS J = 6.87H = 6.65K = 6.50J - K = 0.37
AllWISE W1 = 6.41W2 = 6.22W3 = 6.11W4 = 5.47W1 - W2 = 0.18W3 - W4 = 0.64
APASS-DR9 B = 9.56V = 8.69g' = 9.16r' = 8.42i' = 7.97B - V = 0.88
Please review Digitized Sky Survey Acknowledgment and Copyright.
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Revision History
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4 Otero, Sebastian Alberto 2018-02-27 21:56 UTC Type and spectral type from 2016ApJS..222...15T. UCAC4 position.
3 Otero, Sebastian Alberto 2011-08-11 16:55 UTC Type from reference.
2 Admin, VSX 2010-01-04 23:43 UTC Position updated from the GCVS version of November 2009.
1 Admin, VSX 2005-12-17 20:33 UTC Initial upload.