V1803 Cyg

The object was found in the following catalogues:
  1. The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

  2. SKY2000 - Master Star Catalog

  3. Smithsonian Astrophysical Observatory Star Catalog

  4. The Washington Visual Double Star Catalog, 1996.0

  5. Combined General Catalogue of Variable Stars (Vol. I-III)

catalogues and names V1803 Cyg, 61 Cyg, HR 8085, HD 201091, SAO 70919, FK5: 793, WDS 21069+3845A
constellation Cygnus

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

position, motion, parallax:

position (J2000) RA: 21h 6min 54,6sec DEC: +38 44' 45''
position (J1900) RA: 21h 2min 24,8sec DEC: +38 15' 31''
proper motion (J2000) RA: 4,136 arcsec/a DEC: 3,203 arcsec/a
radial velocity -64 km/s
note: variable radial velocity
rotational velocity <17 km/s (uncertain) (variable)
trigonometric parallax 0,292 arcsec
note (category: dynamical parallaxes): 0.300".


visual magnitude 5,21
(V on UBV Johnson system)

spectral / color information

spectral class K5V
B-V-magnitude 1,18
U-B-magnitude 1,11
R-I-magnitude 0,65

variability information

variable star identification V1803 Cyg
note (category: variability): 5.19 - 5.27V, 350 - 400d.

double/multiple star system information

number of components of multiple star system 6
separation 28,7 arcsec
mag difference (of double or brightest multiple) 0,8
component ID AB
note (category: double and multiple data): AB 5.22 K5V, 6.04 K7V, 722y, a = 24.65". B is HR 8086. Aa x P, 4.9y, a = 0.014". Astrometric measures indicate 3 invisible companions, periods 6, 7 and 12y. Unresolved by speckle interferometry. Suspected planetary companion not substantiated.

miscellaneous information

note (category: group membership): 61 Cyg group.
note (category: miscellaneous): Proper motions for HR 8085 and 8086 taken from Luyten LHS. SAO has only one entry (component A?), but appears to give the mean position of A and B.

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

position, motion, parallax:

position (J2000) RA: 21h 6min 53,951sec DEC: +38 44' 57,83'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,3535 arcsec/a DEC: 3,203 arcsec/a source: 25
radial velocity -64 km/s source: 25
trigonometric parallax 0,292 0,029 arcsec source: 25
galactic coord. (B1950) longitude: 82,25 latitude: -5,81
GCI unit vector (J2000) X: 0,567815 Y: -0,534618 Z: 0,625915


visual 5,21 (observed) source: 25
photovisual 5,6 source: 2
photographic 6,7 source: 16

spectral information:

spectral class K5 source: 96
Morgan-Keenan K5V source: 25
B-magnitude 6,39 0,05 B-V-magnitude 1,18
U-magnitude 7,5 0,05 U-B-magnitude 1,11

variability information:

source of data: 27
variability type 430
var. amplitude 0,1

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 30,4 arcsec
magnitude difference between brightest and second brightest component 0,82
position angle 149

component magnitude spectral class catalogue(s)/name(s)
A 5,21 K5 61 Cyg, HR 8085, HD 201091, SAO 70919
B 6,03 K5 61 Cyg, HR 8086, HD 201092,
C 10,25 A0


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
15 FK5, FK5 Extension and FK5 Supplement
Fricke, W., H. Schwan and T. Lederle, "Fifth Fundamental Catalogue (FK5), Part I. The Basic Fundamental Stars," Veroff. Astronomisches Recheninstitut, No. 32, Heidelberg, Germany, 1988, and Fricke, W., H. Schwan, and T.E. Corbin, "Fifth Fundamental Catalogue (FK5), Part II. The FK5 Extension," Veröff. Astronomisches Recheninstitut, No. 33, Heidelberg, Germany, 1991
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
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 (J1950) RA: 21h 4min 39,935sec DEC: +38 29' 59,1'' 0,004 arcsec
position (J2000) RA: 21h 6min 54,572sec DEC: +38 44' 44,83''
proper motion J1950 (FK4) RA: 0,3523 arcsec/a DEC: 3,185 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,3528 arcsec/a DEC: 3,197 arcsec/a
source of proper motion data Determined by source catalog


visual 5,4 (accuracy: 2 decimals)
source of visual magnitude data Combined magnitude of component stars.

spectral information:

spectral class K5
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Double star - see source catalog for source


source catalogue FK4, catalogue number: 793
Durchmusterung BD+38 4343
Boss General Catalogue 29509
Henry Draper Catalogue 201091
The "SAO Catalog" entry refers to two consecutive HD numbers, the lower of which is given.

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

position and proper motion:

position (J2000) RA: 21h 6,9min DEC: +38 45'
proper motion (J2000) RA: 0 arcsec/a DEC: 0 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
AB 1822 often 86 14,9'' 5,23 6,05 K5V K7V STF2758
1993 149 30,4''
AC 1907 2 196 306,1'' 5,6 - - STF2758
1914 195 321,4''
AD 1918 1 282 304,9'' 5,7 8,6 - STF2758
AE 1918 1 12 306'' 5,7 8,1 - STF2758
Aa 1918 2 31 157,1'' 5,6 10,5 - STF2758
1921 30 140,6''
BC 1902 3 198 277,7'' 6,3 - K7V STF2758
1924 208 375,8''

discoverer information:

discoverer code discoverer reference
STF2758 Struve, F.G.W. -


note 61 Cyg. Premature orbits have been computed for AB. Proper motion of A +4136 +3203. B is BD+38@4344. Proper motion of B +4122 +3125.

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


position (J1950) RA: 21h 4min 39,9sec DEC: +38 29' 59''

variability informations:

variability type BY rotating variable star
magnitute at max. brightness 5,19
magnitute at min. brightness 5,27
photometric system visual, photovisual or Johnson's V


to a study J.D.Dorren, E.F.Guinan, SAO Special Report No.392,Vol.II,49,1982.
to a chart/photograph no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'


ID in the GCVS catalogue 31/1803
constellation Cygnus
notes on existence The star is equivalent to '67612'.

variability type description

variability type description
BY BY Draconis-type variables, which are emission-line dwarfs of dKe-dMe spectral type showing quasiperiodic light changes with periods from a fraction of a day to 120 days and amplitudes from several hundredths to 0.5 mag in V. The light variability is caused by axial rotation of a star with a variable degree of nonuniformity of the surface brightness (spots) and chromospheric activity.
Some of these stars also show flares similar to those of UV Cet stars, and in those cases they also belong to the latter type and are simultaneously considered eruptive variables.