g Equulei

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 g Equ, gam Equ, 5 Equ, HR 8097, HD 201601, SAO 126593, FK5: 1555, WDS 21103+1008A
constellation Equuleus

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

position, motion, parallax:

position (J2000) RA: 21h 10min 20,5sec DEC: +10 7' 54''
position (J1900) RA: 21h 5min 28,7sec DEC: +9 43' 43''
proper motion (J2000) RA: 0,057 arcsec/a DEC: -0,153 arcsec/a
radial velocity -17 km/s
note: variable radial velocity
rotational velocity 8 km/s (uncertain) (variable)
trigonometric parallax 0,028 arcsec
note (category: radial and/or rotational velocities): 1786d, possibly also short period? Rotation 17.492d?
note (category: dynamical parallaxes): 0.011".


visual magnitude 4,69
(V on UBV Johnson system)

spectral / color information

spectral class F0IIIp
B-V-magnitude 0,26
U-B-magnitude 0,1
R-I-magnitude 0,11
note (category: spectra): Extreme oxygen deficiency. Eu, Cr, Sr strong, DyIII identified. The spectrum has been variously classified as cF1, F0III, and F0pV. Also classified A9Vp(SrCrEu st.,Ca wk.).

variability information

variable star identification Gam Equ
note (category: variability): ADS 14702A, Alpha CV 4.58 - 4.77V, 314d, 0 00868d. Magnetic field var. 1786d and 72y. Spectrum var. 72y.

double/multiple star system information

number of components of multiple star system 4
separation 352,5 arcsec
mag difference (of double or brightest multiple) 1,2
component ID AD
note (category: double and multiple data): AB binary, B, 11.6v at 2". C, 12.6v at 48" optical.

miscellaneous information

note (category: group membership): Wolf 630 group.
note (category: stellar radii or diameters): 3 solar radii.

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

position, motion, parallax:

position (J2000) RA: 21h 10min 20,518sec DEC: +10 7' 53,57'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,0038 arcsec/a DEC: -0,153 arcsec/a source: 25
radial velocity -17 km/s source: 25
trigonometric parallax 0,028 0,003 arcsec source: 25
galactic coord. (B1950) longitude: 59,94 latitude: -24,76
GCI unit vector (J2000) X: 0,726772 Y: -0,663972 Z: 0,175909


visual 4,6 (observed) source: 31
photovisual 4,8 source: 2

spectral information:

spectral class F0 source: 96
Morgan-Keenan F0IIIp source: 25
B-magnitude 4,95 0,05 B-V-magnitude 0,26
U-magnitude 5,05 0,05 U-B-magnitude 0,1

variability information:

source of data: 30
variability type 161
var. amplitude 0,19
var. period 0,01

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 1,4 arcsec
magnitude difference between brightest and second brightest component 3,5
position angle 264

component magnitude spectral class catalogue(s)/name(s)
A 4,6 F0 g Equulei, 5 Equ, HR 8097, HD 201601, SAO 126593
B 6,07 A2 6 Equ, HR 8098, HD 201616, SAO 126597


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: 21h 7min 54,579sec DEC: +9 55' 44,82'' 0,005 arcsec
position (J2000) RA: 21h 10min 20,546sec DEC: +10 7' 53,33''
proper motion J1950 (FK4) RA: 0,004 arcsec/a DEC: -0,152 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0042 arcsec/a DEC: -0,156 arcsec/a
source of proper motion data Determined by source catalog


visual 4,8 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class F0p
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.


source catalogue FK4, catalogue number: 1555
Durchmusterung BD+09 4732
Boss General Catalogue 29591
Henry Draper Catalogue 201601

data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

position and proper motion:

position (J2000) RA: 21h 10,3min DEC: +10 8'
proper motion (J2000) RA: 0,057 arcsec/a DEC: -0,153 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 1867 23 276 2,1'' 4,7 8,2 A9V KNT 5
1994 264 1,4''
AC 1877 10 10 41,3'' 4,8 12,6 - BU 71
1925 5 47,7''
AD 1835 7 153 366,2'' 4,8 6 - STF 54
1922 - 352,5''

discoverer information:

discoverer code discoverer reference
KNT 5 Knott, G. -
BU 71 Burnham, S.W. -
STF 54 Struve, F.G.W. -


note Gamma Equ. A is an Alpha CVn-type variable. There apparently is a long-period spectroscopic binary present.

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


position (J1950) RA: 21h 7min 54,6sec DEC: +9 55' 45''

variability informations:

variability type ACVO rotating variable star
magnitute at max. brightness 4,58
magnitute at min. brightness 4,77
photometric system visual, photovisual or Johnson's V
period [d] 0,00868

spectral information

spectral class F0p(Sr-Cr-Eu)


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'


ID in the GCVS catalogue 35/9003
constellation Equuleus
notes on existence The star is equivalent to '0360001 R'.
There are notes in published catalog.

variability type description

variability type description
ACVO 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.

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.