V1931 Cygni

data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)

position, motion, parallax:

position (J2000)	RA: 21h 1min 10.9sec	DEC: +46° 9' 21''
position (B1900)	RA: 20h 57min 41.4sec	DEC: +45° 45' 47''
proper motion (J2000)	RA: 0.006 arcsec/a	DEC: 0.008 arcsec/a
radial velocity	-12 km/s note: spectroscopic binaries
rotational velocity	320 km/s (uncertain) (variable)
galactic coordinates	longitude: 87.15°	latitude: -0.1°

note (category: radial and/or rotational velocities):

2.48257d.

magnitude

visual magnitude

5.37
(V on UBV Johnson system)

spectral / color information

spectral class	B1Ve
B-V-magnitude	-0.21
U-B-magnitude	-0.93

note (category: spectra):

Shell star. Long-term variation in hydrogen emission.

variability information

variable star identification

V1931 Cyg

note (category: variability):

5.34 - 5.48V, probably eclipsing; same period as SB.

double/multiple star system information

separation	2.6 arcsec
mag difference (of double or brightest multiple)	4.5

data from SKY2000 - Master Star Catalog (Myers+ 1997)

position, motion, parallax:

position (J2000)	RA: 21h 1min 10.936sec	DEC: +46° 9' 21.09''	ą0.35 arcsec	source: 17
proper motion (J2000)	RA: 0.0008 arcsec/a	DEC: 0.007 arcsec/a		source: 25
radial velocity	-12 km/s			source: 25
galactic coord. (B1950)	longitude: 87.16°	latitude: -0.1°

magnitude:

visual	5.37 (observed)	source: 25
photovisual	5.2	source: 2
photographic	5.1	source: 16

spectral information:

spectral class	B3		source: 96
Morgan-Keenan	B1Ve		source: 25
B-magnitude	5.16 ą0.05	B-V-magnitude	-0.21
U-magnitude	4.23 ą0.05	U-B-magnitude	-0.93

variability information:

source of data: 27

variability type	300
var. amplitude	0.2

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	2.5 arcsec
magnitude difference between brightest and second brightest component	4.2
position angle	164 °

sources:

2	HD and HDE Catalogs
Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University
16	PPM North and PPM South Catalogs and PPM Supplement
Roser, S., and U. Bastian, "Catalogue of Positions and Proper Motions," A&AS, Vol. 74, p. 449, 1988, and Bastian, U., et al., "Catalogue of Positions and Proper Motions - South," 1993
17	ACRS
Corbin, T.E., and S.E. Urban, Astrographic Catalog Reference Stars, United States Naval Observatory, 1991
19	WDS Catalog
Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996
25	Bright Star Catalogue, 5th edition
Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994
27	Catalog of Red Magnitudes (CRM)
Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 1994
96	SAO or HD/HDE Catalog
Reference from Value 1 or Reference from Value 2

data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)

position and proper motion:

position (B1950)	RA: 20h 59min 26.064sec	DEC: +45° 57' 31.35''	ą0.016 arcsec
position (J2000)	RA: 21h 1min 10.923sec	DEC: +46° 9' 21.27''
proper motion B1950 (FK4)	RA: 0.0003 arcsec/a	DEC: 0.011 arcsec/a	ą0.003 arcsec/a in RA ą0.003 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0006 arcsec/a	DEC: 0.008 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	5.2 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	B3
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Double star in Aitken's Double Star Catalogue (Aitken 1932)

catalogues

source catalogue	GC, catalogue number: 29354
Durchmusterung	BD+45 3364
Boss General Catalogue	29354
Henry Draper Catalogue	200310

data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

position and proper motion:

position (J2000)	RA: 21h 1.2min	DEC: +46° 9'
proper motion (J2000)	RA: 0.009 arcsec/a	DEC: 0.007 arcsec/a

double/multiple star system information:

component	year	number of measures	position angle	angular separation	magnitude of 1st component	magnitude of 2nd component	spectral class(es)	discoverer code
-	1848	12	164°	2.5''	5.2	9.4	B1Ve	STT 426

discoverer information:

discoverer code	discoverer	reference
STT 426	Struve, O.	-

notes:

note	60 Cyg. A is probably a spectroscopic binary, and is the variable V1931 Cyg.

data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)

position:

position (equinox 1950.0)

RA: 20h 59min 26.1sec

DEC: +45° 57' 31''

variability informations:

variability type	E+BE	close binary eclipsing system
magnitute at max. brightness	5.33
magnitute at min. brightness	5.48
photometric system	visual, photovisual or Johnson's V

references

to a study	P.Harmanec, J.Horn, P.Koubsky, H.Bozic, IBVS No.2912,1986.
to a chart/photograph	no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'

miscanellous

ID in the GCVS catalogue	31/1931
constellation	Cygnus
notes on existence	The star is equivalent to '69292'.

variability type description

variability type	description
E	Eclipsing binary systems. These are binary systems with orbital planes so close to the observer's line of sight (the inclination i of the orbital plane to the plane orthogonal to the line of sight is close to 90 deg) that the components periodically eclipse each other. Consequently, the observer finds changes of the apparent combined brightness of the system with the period coincident with that of the components' orbital motion. EA Algol (Beta Persei)-type eclipsing systems. Binaries with spherical or slightly ellipsoidal components. It is possible to specify, for their light curves, the moments of the beginning and end of the eclipses. Between eclipses the light remains almost constant or varies insignificantly because of reflection effects, slight ellipsoidality of components, or physical variations. Secondary minima may be absent. An extremely wide range of periods is observed, from 0.2 to >= 10000 days. Light amplitudes are also quite different and may reach several magnitudes. EB Beta Lyrae-type eclipsing systems. These are eclipsing systems having ellipsoidal components and light curves for which it is impossible to specify the exact times of onset and end of eclipses because of a continuous change of a system's apparent combined brightness between eclipses; secondary minimum is observed in all cases, its depth usually being considerably smaller than that of the primary minimum; periods are mainly longer than 1 day. The components generally belong to early spectral types (B-A). Light amplitudes are usually <2 mag in V. EW W Ursae Majoris-type eclipsing variables. These are eclipsers with periods shorter than 1 days, consisting of ellipsoidal components almost in contact and having light curves for which it is impossible to specify the exact times of onset and end of eclipses. The depths of the primary and secondary minima are almost equal or differ insignificantly. Light amplitudes are usually <0.8 mag in V. The components generally belong to spectral types F-G and later.
BE	It becomes more and more clear that, although the majority of Be stars are photometrically variable, not all of them could be properly called GCAS variables. Quite a number of them show small-scale variations not necessarily related to shell events; in some cases the variations are quasi-periodic. By now we are not able to present an elaborated system of classification for Be variables, but we adopt a decision that in the cases when a Be variable cannot be readily described as a GCAS star we give simply BE for the type of variability.

catalogues and names	V1931 Cyg, 60 Cyg, HR 8053, HD 200310, SAO 50359, BD +45 3364, WDS 21012+4609
constellation	Cygnus