VW Cephei
catalogues and names
| catalogues and names | VW Cep, HD 197433, SAO 9828, BD +75 752, WDS 20374+7536 |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 20h 37min 21.515sec | DEC: +75° 36' 1.75'' | ±0.43 arcsec | source: 16 |
| position (2000.73) | RA: 20h 37min 21sec | DEC: +75° 36' 12'' | JD: 2451810.12 | |
| proper motion (J2000) | RA: 0.0871 arcsec/a | DEC: 0.551 arcsec/a | source: 16 | |
| radial velocity | 10 km/s | source: 26 | ||
| trigonometric parallax | 0.049 arcsec | ±0.005 arcsec | source: 26 | |
| galactic coord. (B1950) | longitude: 109.22° | latitude: 20.06° | ||
magnitude:
| visual | 7.2 (observed) | source: 31 |
| photovisual | 7.6 | source: 2 |
| photographic | 8.3 | source: 16 |
spectral information:
| spectral class | G5 | source: 96 | |
| Morgan-Keenan | K0/1V+G5/6 | source: 26 | |
| B-magnitude | 7.94 ±0.2 | B-V-magnitude | 0.86 |
| U-magnitude | 8.38 ±0.2 | U-B-magnitude | 0.44 |
variability information:
| variability type | 10 |
| var. amplitude | 0.45 |
| var. period | 0.28 |
| var. epoch | 2444157 10. October 1979, 12:00:00 UT |
| next max light | 2451810.24 22. September 2000, 17:45:36 UT |
double/multiple star system information:
| separation between brightest and second brightest component | 0.5 arcsec |
| magnitude difference between brightest and second brightest component | 2.9 |
| position angle | 285 ° |
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 | |
| 19 | WDS Catalog |
| Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996 | |
| 26 | Bright Star Supplement |
| Hoffleit, D. and Warren, W.H. Jr., A Supplement to the Bright Star Catalogue, 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 (B1950) | RA: 20h 38min 3.009sec | DEC: +75° 24' 58.37'' | ±0.037 arcsec |
| position (2000.73) | RA: 20h 37min 16sec | DEC: +75° 35' 43'' | JD: 2451810.12 |
| position (J2000) | RA: 20h 37min 21.658sec | DEC: +75° 36' 2.59'' | |
| proper motion B1950 (FK4) | RA: 0.0899 arcsec/a | DEC: 0.56 arcsec/a | ±0.006 arcsec/a in RA ±0.006 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0.0895 arcsec/a | DEC: 0.561 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 7.1 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | G5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Variable star in visual magnitude in source catalog |
catalogues
| source catalogue | GC, catalogue number: 28804 |
| Durchmusterung | BD+75 752 |
| Boss General Catalogue | 28804 |
| Henry Draper Catalogue | 197433 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 20h 37.4min | DEC: +75° 36' |
| proper motion (J2000) | RA: 0.331 arcsec/a | DEC: 0.555 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 |
| - | 1974 | 11 | 223° | 0.6'' | 7.1 | 10 | K0V | HEI 7 |
| 1988 | 285° | 0.5'' |
discoverer information:
| discoverer code | discoverer | reference |
| HEI 7 | - |
notes:
| note | P = 30.4yr., a = 0.51", motion direct. A is the W UMa system VW Cep. BD+74@889, one degree distant, shares common proper motion and radial velocity. |
data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
| position (B1900) | RA: 20h 38.7min | DEC: +75° 14' |
magnitudes, spectral classes, orbital elements:
| author: | J.L. Hershey |
| date of observation: | 1974 |
| spectral class component B: | K0V |
| spectral class component B: | K0V |
| period [y]: | 30.45 |
| semi-major axis [arcsec]: | 0.51 |
| inclination [deg]: | 29.2 |
| node [deg]: | 0.9 (ascending) |
| equinox of node: | 2000 |
| eccentricity: | 0.595 |
| time of periastron passage: | 1966.48 |
| grade: | reliable |
| reference: | Astron. J. 80, 662; 1975. |
| notes | The primary is the class W eclipsing and spectroscopic binary VW Cep, P = 0.278 d. The light amplitude is 0.5 mag. and the light curve is variable. The quoted orbit is astrometric; only the value of the semi-major axis was computed after the companion was resolved. Ascending node tentatively identified from what appears to be a lighttime effect superimposed on intrinsic period changes in the eclipsing pair. BD +74 889 (mag. 7.9, G5) 1 degree distant appears to share the proper motion. |