Mekbuda
| catalogues and names | Mekbuda, z Gem, zet Gem, 43 Gem, HR 2650, HD 52973, SAO 79031, FK5: 269, WDS 07041+2034A |
| constellation | Gemini |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Mekbuda. |
position, motion, parallax:
| position (J2000) | RA: 7h 4min 6,5sec | DEC: +20° 34' 13'' |
| position (J1900) | RA: 6h 58min 10,6sec | DEC: +20° 43' 2'' |
| proper motion (J2000) | RA: -0,009 arcsec/a | DEC: 0 arcsec/a |
| radial velocity | 7 km/s note: spectroscopic binaries |
|
| rotational velocity | =<54 km/s (uncertain) (variable) | |
| trigonometric parallax | -0,006 arcsec | |
| note (category: radial and/or rotational velocities): | Same period. |
magnitude
| visual magnitude | 3,79 (V on UBV Johnson system) |
spectral / color information
| spectral class | F7-G3Ib |
| B-V-magnitude | 0,79 |
| U-B-magnitude | 0,62 |
| R-I-magnitude | 0,41 |
variability information
| variable star identification | Zet Gem |
| note (category: variability): | ADS 5742A, CDelta 3.62 - 4.18V, 10.15073d. Period decreasing 3.1s/y. |
double/multiple star system information
| number of components of multiple star system | 6 |
| separation | 0,1 arcsec |
| mag difference (of double or brightest multiple) | 0 |
| component ID | O |
| note (category: double and multiple data): | Component A is suspected occultation double, 4.5, 4.5v, sep. 0.1". B, 10.5v at 87". C, +20d1686, 7.55V, +0.62(B-V), +0. +0.07(U-B), G1V at 96" has high proper motion, 0.100", optical, vsini =<54k/s. Other components fainter. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 7h 4min 6,522sec | DEC: +20° 34' 13'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: -0,0007 arcsec/a | DEC: -0,001 arcsec/a | source: 25 | |
| radial velocity | 7 km/s | source: 25 | ||
| galactic coord. (B1950) | longitude: 195,75° | latitude: 11,9° | ||
| GCI unit vector (J2000) | X: -0,25849 | Y: 0,899851 | Z: 0,351356 | |
magnitude:
| visual | 3,7 (observed) | source: 31 |
spectral information:
| spectral class | G0P | source: 29 | |
| Morgan-Keenan | F7-G3Ib | source: 25 | |
| B-magnitude | 4,58 ±0,05 | B-V-magnitude | 0,79 |
| U-magnitude | 5,2 ±0,05 | U-B-magnitude | 0,62 |
variability information:
| variability type | 111 |
| var. amplitude | 0,56 |
| var. period | 10,15 |
| var. epoch | 2443806 24. October 1978, 12:00:00 UT |
| next max light | 2451621,5 18. March 2000, 00:00:00 UT |
double/multiple star system information:
| separation between brightest and second brightest component | 87 arcsec |
| magnitude difference between brightest and second brightest component | 6,7 |
| position angle | 84 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 3,7 | G0P | Mekbuda, z Geminorum, 43 Gem, HR 2650, HD 52973, SAO 79031 |
| B | 7,58 | G5 |
sources:
| 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 | |
| 29 | SAOJ2000 |
| SAO on FK5 at J2000, 1989 | |
| 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 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (J1950) | RA: 7h 1min 8,627sec | DEC: +20° 38' 43,45'' | ±0,003 arcsec |
| position (J2000) | RA: 7h 4min 6,521sec | DEC: +20° 34' 12,99'' | |
| proper motion J1950 (FK4) | RA: -0,0006 arcsec/a | DEC: -0,003 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0007 arcsec/a | DEC: 0 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 3,9 (accuracy: 2 decimals) |
| source of visual magnitude data | Arithmetic mean of maximum and minimum magnitudes of a variable star |
spectral information:
| spectral class | G0p |
| 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 | FK4, catalogue number: 269 |
| Durchmusterung | BD+20 1687 |
| Boss General Catalogue | 9313 |
| Henry Draper Catalogue | 52973 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 7h 4,1min | DEC: +20° 34' |
| proper motion (J2000) | RA: -0,009 arcsec/a | DEC: -0,001 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 | 1880 | 10 | 84° | 87'' | 3,8 | 10,5 | F7-G3Ib | SHJ 77 |
| AC | 1821 | 19 | 355° | 91'' | 3,8 | 7,56 | - | SHJ 77 |
| 1984 | 348° | 99,8'' | ||||||
| Aa | 1905 | 2 | 83° | 80'' | - | 12 | - | SHJ 77 |
| 1984 | 352° | 70,3'' | ||||||
| BC | 1913 | 1 | 310° | 133'' | 10,6 | 8,7 | - | SHJ 77 |
| CR | 1907 | 1 | 166° | 27,2'' | 7,56 | 12,9 | G0 | SHJ 77 |
discoverer information:
| discoverer code | discoverer | reference |
| SHJ 77 | South & Herschel | - |
notes:
| note | Zeta Gem. A is a Cepheid, and an occultation double. |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 7h 1min 8,6sec | DEC: +20° 38' 43'' |
variability informations:
| variability type | DCEP | pulsating variable star |
| magnitute at max. brightness | 3,62 | |
| magnitute at min. brightness | 4,18 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2443805,927 24. October 1978, 10:14:53 UT |
|
| period [d] | 10,15073 | |
| next maximum light [JD] | 2451621,9891 18. March 2000, 11:44:18 UT |
|
| rising time | 50 % of period |
spectral information
| spectral class | F7Ib-G3Ib |
references
| to a study | the main characteristics of the star was determined by the authors themselves |
| to a chart/photograph | Vol. I GCVS (see Kholopov et al. 1985-1988) |
miscanellous
| ID in the GCVS catalogue | 38/9006 |
| constellation | Gemini |
| notes on existence | The star is equivalent to '0389007 eta'. |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| DCEP | These are the classical cepheids, or Delta Cep-type variables. Comparatively young objects that have left the main sequence and evolved into the instability strip of the Hertzsprung-Russell (H-R) diagram, they obey the well-known Cepheid period-luminosity relation and belong to the young disk population. DCEP stars are present in open clusters. They display a certain relation between the shapes of their light curves and their periods. |