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 Deneb, a Cyg, alf Cyg, 50 Cyg, HR 7924, HD 197345, SAO 49941, FK5: 777, WDS 20414+4517
other names Deneb Cygni, Deneb el Adige, Arided, Aridif, Gallina, Arrioph
constellation Cygnus

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

note (category: star names): DENEB; Deneb Cygni; Deneb el Adige; Arided; Aridif; Gallina; Arrioph.

object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

position, motion, parallax:

position (J2000) RA: 20h 41min 25,9sec DEC: +45 16' 49''
position (J1900) RA: 20h 38min 1,3sec DEC: +44 55' 22''
proper motion (J2000) RA: 0,003 arcsec/a DEC: 0,002 arcsec/a
radial velocity -5 km/s
note: spectroscopic binaries
note: orbital data avaible
rotational velocity 21 km/s (uncertain) (variable)
trigonometric parallax -0,006 arcsec
note (category: radial and/or rotational velocities): Mass loss 3x10E-10 solar masses/y.


visual magnitude 1,25
(V on UBV Johnson system)

spectral / color information

spectral class A2Ia
B-V-magnitude 0,09
U-B-magnitude -0,24
R-I-magnitude 0,1

variability information

variable star identification Alp Cyg
note (category: variability): Alpha Cyg 1.21 - 1.29V. Change in H:H epsilon. No emission recorded before 1944.

double/multiple star system information

separation 75,4 arcsec
mag difference (of double or brightest multiple) 10
note (category: spectroscopic binaries): The following two orbits are reported as equally probable: 846.8d, K 3.12k/s, V0 -2.81k/s; 776.4d, K 2.61k/s, V0 -3.24k/s.

miscellaneous information

note (category: group membership): Cyg OB7.

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

position, motion, parallax:

position (J2000) RA: 20h 41min 25,917sec DEC: +45 16' 49,31'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,0003 arcsec/a DEC: 0,002 arcsec/a source: 25
radial velocity -5 km/s source: 25
galactic coord. (B1950) longitude: 84,29 latitude: 2
GCI unit vector (J2000) X: 0,455649 Y: -0,536182 Z: 0,710558


visual 1,2 (observed) source: 31
photovisual 1,3 source: 2

spectral information:

spectral class A2 source: 96
Morgan-Keenan A2Ia source: 25
B-magnitude 1,34 0,05 B-V-magnitude 0,09
U-magnitude 1,1 0,05 U-B-magnitude -0,24

variability information:

source of data: 30
variability type 133
var. amplitude 0,08

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 75,4 arcsec
magnitude difference between brightest and second brightest component 10,4
position angle 106


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
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
30 GCVS, 4th edition
Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88
31 CRM' (non-GCVS variable data)
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: 20h 39min 43,539sec DEC: +45 6' 3,12'' 0,003 arcsec
position (J2000) RA: 20h 41min 25,93sec DEC: +45 16' 49,29''
proper motion J1950 (FK4) RA: 0,0001 arcsec/a DEC: 0,005 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0004 arcsec/a DEC: 0,002 arcsec/a
source of proper motion data Determined by source catalog


visual 1,3 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class A2p
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.


source catalogue FK4, catalogue number: 777
Durchmusterung BD+44 3541
Boss General Catalogue 28846
Henry Draper Catalogue 197345

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

position and proper motion:

position (J2000) RA: 20h 41,4min DEC: +45 17'
proper motion (J2000) RA: 0,003 arcsec/a DEC: 0,002 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
- 1879 7 106 75,4'' 1,25 11,7 A2Iae H 73

discoverer information:

discoverer code discoverer reference
H 73 Herschel, W. -


note H N 73. Alpha Cyg.

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


position (J1950) RA: 20h 39min 43,5sec DEC: +45 6' 3''

variability informations:

variability type ACYG pulsating variable star
magnitute at max. brightness 1,21
magnitute at min. brightness 1,29
photometric system visual, photovisual or Johnson's V

spectral information

spectral class A2Iae


to a study Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'


ID in the GCVS catalogue 31/9001
constellation Cygnus
notes on existence The star is equivalent to '0319019 tau'.
There are notes in published catalog.

variability type description

variability type description
ACYG Variables of the Alpha Cygni type, which are nonradially pulsating supergiants of Bep-AepIa spectral types. The light changes with amplitudes of the order of 0.1 mag often seem irregular, being caused by the superposition of many oscillations with close periods. Cycles from several days to several weeks are observed.