Gomeisa
| catalogues and names | Gomeisa, b CMi, bet CMi, 3 CMi, HR 2845, HD 58715, SAO 115456, FK5: 285, WDS 07271+0817A |
| other names | Algomeyla, Gomelza |
| constellation | Canis Minor |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Gomeisa; Algomeyla; Gomelza. |
position, motion, parallax:
| position (J2000) | RA: 7h 27min 9sec | DEC: +8° 17' 22'' |
| position (J1900) | RA: 7h 21min 43,6sec | DEC: +8° 29' 27'' |
| proper motion (J2000) | RA: -0,052 arcsec/a | DEC: -0,038 arcsec/a |
| radial velocity | 22 km/s note: spectroscopic binaries |
|
| rotational velocity | 276 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,019 arcsec | |
magnitude
| visual magnitude | 2,9 (V on UBV Johnson system) |
spectral / color information
| spectral class | B8Ve |
| B-V-magnitude | -0,09 |
| U-B-magnitude | -0,28 |
| R-I-magnitude | -0,06 |
| note (category: spectra): | Rotationally unstable Be shell star. |
variability information
| variable star identification | Bet CMi |
| note (category: variability): | Gamma Cas 2.84 - 2.92V. |
double/multiple star system information
| number of components of multiple star system | 5 |
| separation | 138,7 arcsec |
| mag difference (of double or brightest multiple) | 7,8 |
| component ID | AE |
| note | Worley (1978) update of the IDS |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 7h 27min 9,039sec | DEC: +8° 17' 21,5'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: -0,0035 arcsec/a | DEC: -0,038 arcsec/a | source: 25 | |
| radial velocity | 22 km/s | source: 25 | ||
| trigonometric parallax | 0,019 | ±0,002 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 209,53° | latitude: 11,68° | ||
| GCI unit vector (J2000) | X: -0,36729 | Y: 0,918865 | Z: 0,144172 | |
magnitude:
| visual | 2,8 (observed) | source: 31 |
| photovisual | 3,1 | source: 2 |
spectral information:
| spectral class | B8 | source: 96 | |
| Morgan-Keenan | B8Ve | source: 25 | |
| B-magnitude | 2,81 ±0,05 | B-V-magnitude | -0,09 |
| U-magnitude | 2,53 ±0,05 | U-B-magnitude | -0,28 |
variability information:
| variability type | 264 |
| var. amplitude | 0,08 |
double/multiple star system information:
| separation between brightest and second brightest component | 47,8 arcsec |
| magnitude difference between brightest and second brightest component | 10,1 |
| position angle | 82 ° |
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: 7h 24min 26,357sec | DEC: +8° 23' 29,89'' | ±0,003 arcsec |
| position (J2000) | RA: 7h 27min 9,038sec | DEC: +8° 17' 21,5'' | |
| proper motion J1950 (FK4) | RA: -0,0036 arcsec/a | DEC: -0,04 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0035 arcsec/a | DEC: -0,038 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 3,1 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | B8 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 285 |
| Durchmusterung | BD+08 1774 |
| Boss General Catalogue | 9947 |
| Henry Draper Catalogue | 58715 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 7h 24min 26,4sec | DEC: +8° 23' 30'' |
variability informations:
| variability type | GCAS | eruptive variable star |
| magnitute at max. brightness | 2,84 | |
| magnitute at min. brightness | 2,92 | |
| photometric system | visual, photovisual or Johnson's V |
spectral information
| spectral class | B8Ve |
references
| to a chart/photograph | no chart is avaible, but the star is contained in the 'Bonner Durchmusterung' |
miscanellous
| ID in the GCVS catalogue | 15/9002 |
| constellation | Canes Venatici |
| notes on existence | The star is equivalent to '0160001 R'. |
variability type description
| variability type | description |
| GCAS | Eruptive irregular variables of the Gamma Cas type. These are rapidly rotating B III-IVe stars with mass outflow from their equatorial zones. The formation of equatorial rings or disks is often accompanied by temporary fading. Light amplitudes may reach 1.5 mag in V. |