Alpheratz


The object was found in the following catalogues:
  1. The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

  2. SKY2000 - Master Star Catalog

  3. Smithsonian Astrophysical Observatory Star Catalog

  4. The Washington Visual Double Star Catalog, 1996.0

  5. Combined General Catalogue of Variable Stars (Vol. I-III)


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.

object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

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:

source of data: 30
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:

source of data: 19
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.