Gomeisa


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 Gomeisa, b CMi, bet CMi, 3 CMi, HR 2845, HD 58715, SAO 115456, FK5: 285, WDS 07271+0817A
other names Algomeyla, Gomelza
constellation Canis Minor

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

note (category: star names): Gomeisa; Algomeyla; Gomelza.

position, motion, parallax:

position (J2000) RA: 7h 27min 9sec DEC: +8 17' 22''
position (J1900) RA: 7h 21min 43,6sec DEC: +8 29' 27''
proper motion (J2000) RA: -0,052 arcsec/a DEC: -0,038 arcsec/a
radial velocity 22 km/s
note: spectroscopic binaries
rotational velocity 276 km/s (uncertain) (variable)
trigonometric parallax 0,019 arcsec

magnitude

visual magnitude 2,9
(V on UBV Johnson system)

spectral / color information

spectral class B8Ve
B-V-magnitude -0,09
U-B-magnitude -0,28
R-I-magnitude -0,06
note (category: spectra): Rotationally unstable Be shell star.

variability information

variable star identification Bet CMi
note (category: variability): Gamma Cas 2.84 - 2.92V.

double/multiple star system information

number of components of multiple star system 5
separation 138,7 arcsec
mag difference (of double or brightest multiple) 7,8
component ID AE
note Worley (1978) update of the IDS

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

position, motion, parallax:

position (J2000) RA: 7h 27min 9,039sec DEC: +8 17' 21,5'' 0,06 arcsec source: 15
proper motion (J2000) RA: -0,0035 arcsec/a DEC: -0,038 arcsec/a source: 25
radial velocity 22 km/s source: 25
trigonometric parallax 0,019 0,002 arcsec source: 25
galactic coord. (B1950) longitude: 209,53 latitude: 11,68
GCI unit vector (J2000) X: -0,36729 Y: 0,918865 Z: 0,144172

magnitude:

visual 2,8 (observed) source: 31
photovisual 3,1 source: 2

spectral information:

spectral class B8 source: 96
Morgan-Keenan B8Ve source: 25
B-magnitude 2,81 0,05 B-V-magnitude -0,09
U-magnitude 2,53 0,05 U-B-magnitude -0,28

variability information:

source of data: 30
variability type 264
var. amplitude 0,08

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 47,8 arcsec
magnitude difference between brightest and second brightest component 10,1
position angle 82

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
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: 7h 24min 26,357sec DEC: +8 23' 29,89'' 0,003 arcsec
position (J2000) RA: 7h 27min 9,038sec DEC: +8 17' 21,5''
proper motion J1950 (FK4) RA: -0,0036 arcsec/a DEC: -0,04 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,0035 arcsec/a DEC: -0,038 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 3,1 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class B8
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue FK4, catalogue number: 285
Durchmusterung BD+08 1774
Boss General Catalogue 9947
Henry Draper Catalogue 58715

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

position:

position (J1950) RA: 7h 24min 26,4sec DEC: +8 23' 30''

variability informations:

variability type GCAS eruptive variable star
magnitute at max. brightness 2,84
magnitute at min. brightness 2,92
photometric system visual, photovisual or Johnson's V

spectral information

spectral class B8Ve

references

to a chart/photograph no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'

miscanellous

ID in the GCVS catalogue 15/9002
constellation Canes Venatici
notes on existence The star is equivalent to '0160001 R'.

variability type description

variability type description
GCAS Eruptive irregular variables of the Gamma Cas type. These are rapidly rotating B III-IVe stars with mass outflow from their equatorial zones.
The formation of equatorial rings or disks is often accompanied by temporary fading. Light amplitudes may reach 1.5 mag in V.