Gomeisa

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 (B1900)	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
galactic coordinates	longitude: 209.52°	latitude: 11.68°

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

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 arcsec		±0.002 arcsec	source: 25
galactic coord. (B1950)	longitude: 209.53°	latitude: 11.68°

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 (B1950)	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 B1950 (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 (equinox 1950.0)

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	Canis Minor
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.

catalogues and names	Gomeisa, b CMi, bet CMi, 3 CMi, HR 2845, HD 58715, SAO 115456, BD +8 1774, FK5: 285, WDS 07271+0817A
other names	Algomeyla, Gomelza
constellation	Canis Minor