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

catalogues and names Merope, V0971 Tau, 23 Tau, HR 1156, HD 23480, SAO 76172
constellation Taurus

data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)

note (category: star names): Merope.

position, motion, parallax:

position (J2000) RA: 3h 46min 19,6sec DEC: +23 56' 54''
position (J1900) RA: 3h 40min 23,3sec DEC: +23 38' 13''
proper motion (J2000) RA: 0,021 arcsec/a DEC: -0,045 arcsec/a
radial velocity 6 km/s
note: variable radial velocity
rotational velocity 282 km/s (uncertain) (variable)


visual magnitude 4,18
(V on UBV Johnson system)

spectral / color information

spectral class B6IVe
B-V-magnitude -0,06
U-B-magnitude -0,42
R-I-magnitude -0,04

variability information

variable star identification V971 Tau
note (category: variability): Variable hydrogen emission.

double/multiple star system information

note (category: double and multiple data): Suspected double probably single star.

miscellaneous information

note (category: group membership): Pleiades cluster; Mel 22 #980; in reflection nebula; Pleiades nebula; member assoc. Tau R1 at 110 pc.

data from SKY2000 - Master Star Catalog (Myers+ 1997)

position, motion, parallax:

position (J2000) RA: 3h 46min 19,537sec DEC: +23 56' 53,42'' 0,43 arcsec source: 16
proper motion (J2000) RA: 0,0008 arcsec/a DEC: -0,057 arcsec/a source: 25
radial velocity 6 km/s source: 25
galactic coord. (B1950) longitude: 166,57 latitude: -23,75
GCI unit vector (J2000) X: 0,503339 Y: 0,762815 Z: 0,40591


visual 4,18 (observed) source: 25
photovisual 4,3 source: 2
photographic 4,1 source: 16

spectral information:

spectral class B5 source: 96
Morgan-Keenan B6IVe source: 25
B-magnitude 4,12 0,05 B-V-magnitude -0,06
U-magnitude 3,7 0,05 U-B-magnitude -0,42

variability information:

source of data: 27
variability type 140
var. amplitude 0


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
25 Bright Star Catalogue, 5th edition
Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994
27 Catalog of Red Magnitudes (CRM)
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: 3h 43min 21,195sec DEC: +23 47' 38,99'' 0,018 arcsec
position (J2000) RA: 3h 46min 19,589sec DEC: +23 56' 54,06''
proper motion J1950 (FK4) RA: 0,0016 arcsec/a DEC: -0,042 arcsec/a 0,003 arcsec/a in RA
0,002 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0015 arcsec/a DEC: -0,045 arcsec/a
source of proper motion data Determined by source catalog


visual 4,3 (accuracy: 2 decimals)
source of visual magnitude data Taken from Harvard or San Luis photometry.

spectral information:

spectral class B5
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.


source catalogue GC, catalogue number: 4512
Durchmusterung BD+23 522
Boss General Catalogue 4512
Henry Draper Catalogue 23480

data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)


position (J1950) RA: 3h 43min 21,2sec DEC: +23 47' 39''

variability informations:

variability type BCEP pulsating variable star
magnitute at max. brightness 4,18
magnitute amplitude 0,01
photometric system visual, photovisual or Johnson's V


to a study B.J.McNamara, ApJ 312,778,1987.
to a chart/photograph no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'


ID in the GCVS catalogue 78/971
constellation Taurus
notes on existence The star is equivalent to '69056'.

variability type description

variability type description
BCEP Variables of the Beta Cephei type (Beta Cep, Beta CMa), which are pulsating O8-B6 I-V stars with periods of light and radial-velocity variations in the range of 0.1 - 0.6 days and light amplitudes from 0.01 to 0.3 mag in V. The light curves are similar in shape to average radial-velocity curves but lag in phase by a quarter of the period, so that maximum brightness corresponds to
maximum contraction, i.e., to minimum stellar radius. The majority of these stars probably show radial pulsations, but some (V649 Per) display nonradial pulsations; multiperiodicity is characteristic of many of these stars.