Deneb
| 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. |
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. |
magnitude
| 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 | |
magnitude:
| 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:
| variability type | 133 |
| var. amplitude | 0,08 |
double/multiple star system information:
| separation between brightest and second brightest component | 75,4 arcsec |
| magnitude difference between brightest and second brightest component | 10,4 |
| position angle | 106 ° |
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 | |
| 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 | ||
magnitude:
| 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. |
catalogues
| 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. | - |
notes:
| note | H N 73. Alpha Cyg. |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| 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 |
references
| 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' |
miscanellous
| 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. |