Alpheratz
| catalogues and names | Alpheratz, a And, alf And, 21 And, HR 15, HD 358, SAO 73765, FK5: 1, WDS 00084+2905 |
| other names | Alpherat, Sirrah, Sirah |
| constellation | Andromeda |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | ALPHERATZ; Alpherat; Sirrah; Sirah. Also formerly called Delta Peg. |
position, motion, parallax:
| position (J2000) | RA: 0h 8min 23,3sec | DEC: +29° 5' 26'' |
| position (J1900) | RA: 0h 3min 13sec | DEC: +28° 32' 18'' |
| proper motion (J2000) | RA: 0,136 arcsec/a | DEC: -0,163 arcsec/a |
| radial velocity | -12 km/s note: spectroscopic binaries note: orbital data avaible |
|
| rotational velocity | 56 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,032 arcsec | |
magnitude
| visual magnitude | 2,06 (V on UBV Johnson system) |
spectral / color information
| spectral class | B8IVpMnHg |
| B-V-magnitude | -0,11 |
| U-B-magnitude | -0,46 |
| R-I-magnitude | -0,1 |
| note (category: spectra): | Gallium II lines strong. HgMn star. Spectrum appears earlier at shorter wavelengths. |
variability information
| variable star identification | Alp And |
| note (category: variability): | Alpha CV 2.02 - 2.06V, 0.9636 or 0.966222d. Some spectral lines vary same period, others half period, some nonvariable. |
double/multiple star system information
| separation | 81,5 arcsec |
| mag difference (of double or brightest multiple) | 8,5 |
| note (category: spectroscopic binaries): | ADS 94A, 96.6960d, K 30.8k/s, V0 -11.6k/s, asini 34.2. |
miscellaneous information
| note (category: group membership): | Pleiades group. |
| note (category: stellar radii or diameters): | Radius 5 solar. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 0h 8min 23,265sec | DEC: +29° 5' 25,58'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: 0,0104 arcsec/a | DEC: -0,163 arcsec/a | source: 25 | |
| radial velocity | -12 km/s | source: 25 | ||
| trigonometric parallax | 0,032 | ±0,003 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 111,74° | latitude: -32,84° | ||
| GCI unit vector (J2000) | X: 0,873268 | Y: 0,031975 | Z: 0,48619 | |
magnitude:
| visual | 2,06 (observed) | source: 25 |
| photovisual | 2,2 | source: 2 |
spectral information:
| spectral class | A0 | source: 96 | |
| Morgan-Keenan | B9IV:pHgMn | source: 25 | |
| B-magnitude | 1,95 ±0,05 | B-V-magnitude | -0,11 |
| U-magnitude | 1,49 ±0,05 | U-B-magnitude | -0,46 |
variability information:
| variability type | 160 |
| var. amplitude | 0,04 |
| var. period | 0,97 |
| var. epoch | 2441862 28. June 1973, 12:00:00 UT |
| next max light | 2451616,32 12. March 2000, 19:40:48 UT |
double/multiple star system information:
| separation between brightest and second brightest component | 81,5 arcsec |
| magnitude difference between brightest and second brightest component | 9,3 |
| position angle | 280 ° |
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 | |
| 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: 0h 5min 47,841sec | DEC: +28° 48' 52,12'' | ±0,003 arcsec |
| position (J2000) | RA: 0h 8min 23,269sec | DEC: +29° 5' 25,55'' | |
| proper motion J1950 (FK4) | RA: 0,0104 arcsec/a | DEC: -0,158 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0104 arcsec/a | DEC: -0,163 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 2,1 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | A0p |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 1 |
| Durchmusterung | BD+28 4 |
| Boss General Catalogue | 127 |
| Henry Draper Catalogue | 358 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 0h 8,4min | DEC: +29° 5' |
| proper motion (J2000) | RA: 0,136 arcsec/a | DEC: -0,163 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 |
| - | 1830 | 18 | 264° | 64,9'' | 2,06 | 11,4 | B8IVpMnHg | H 32 |
| 1954 | 280° | 81,5'' |
discoverer information:
| discoverer code | discoverer | reference |
| H 32 | Herschel, W. | - |
notes:
| note | H V 32. Alpha And. A is a spectroscopic binary, P = 96.7d. Proper motion of the optical companion, B, -004 -024. |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 0h 5min 47,8sec | DEC: +28° 48' 52'' |
variability informations:
| variability type | ACV | rotating variable star |
| magnitute at max. brightness | 2,02 | |
| magnitute at min. brightness | 2,06 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2441862,126 28. June 1973, 15:01:26 UT |
|
| period [d] | 0,966222 | |
| next maximum light [JD] | 2451617,103312 13. March 2000, 14:28:46 UT |
spectral information
| spectral class | B8IVp(Hg-Mn) |
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 | 1/9001 |
| constellation | Andromeda |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| ACV | Alpha2 Canum Venaticorum variables. These are main-sequence stars with spectral types B8p-A7p and displaying strong magnetic fields. Spectra show abnormally strong lines of Si, Sr, Cr, and rare earths whose intensities vary with rotation. They exhibit magnetic field and brightness changes (periods of 0.5-160 days or more). The amplitudes of the brightness changes are usually withine 0.01-0.1 mag in V. ACVO Rapidly oscillating Alpha2 CVn variables. These are nonradially pulsating, rotating magnetic variables of Ap spectral type (DO Eri). Pulsation periods are in the range of 6-12 mmag (0.004-0.01 days), while amplitudes of light variation caused by the pulsation are about 0.01 mag in V. The pulsational variations are superposed on those caused by rotation. |