catalogues and names

The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

SKY2000 - Master Star Catalog

Smithsonian Astrophysical Observatory Star Catalog

The Washington Visual Double Star Catalog, 1996.0

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

catalogues and names

catalogues and names	s Gem, sig Gem, 75 Gem, HR 2973, HD 62044, SAO 79638, BD +29 1590, WDS 07433+2853
constellation	Gemini

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

position, motion, parallax:

position (J2000)	RA: 7h 43min 18.7sec	DEC: +28° 53' 1''
position (B1900)	RA: 7h 37min 3.7sec	DEC: +29° 7' 32''
proper motion (J2000)	RA: 0.065 arcsec/a	DEC: -0.232 arcsec/a
radial velocity	46 km/s note: spectroscopic binaries, single lined spectra note: orbital data avaible
rotational velocity	22 km/s (uncertain) (variable)
trigonometric parallax	0.018 arcsec
galactic coordinates	longitude: 191.19°	latitude: 23.27°

magnitude

visual magnitude

4.28 (V on UBV Johnson system)

spectral / color information

spectral class	K1III
B-V-magnitude	1.12
U-B-magnitude	0.97
R-I-magnitude
IR-note	object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

note (category: spectra):

H alpha emission.

variability information

variable star identification

Sig Gem

note (category: variability):

RS 4.13 - 4.29V, 19.423d.

double/multiple star system information

separation	182.2 arcsec
mag difference (of double or brightest multiple)	6.5
note	Worley (1978) update of the IDS

note (category: spectroscopic binaries):

19.605d, K 34.2k/s, V0 +45.8k/s, asini 9.22. Possible radio binary.

miscellaneous information

note (category: group membership):

Eta Cep group.

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

position, motion, parallax:

position (J2000)	RA: 7h 43min 18.721sec	DEC: +28° 53' 0.74''	±0.2 arcsec	source: 52
proper motion (J2000)	RA: 0.0047 arcsec/a	DEC: -0.225 arcsec/a		source: 25
radial velocity	46 km/s			source: 25
trigonometric parallax	0.018 arcsec		±0.002 arcsec	source: 25
galactic coord. (B1950)	longitude: 191.19°	latitude: 23.27°

magnitude:

visual	4.1 (observed)	source: 31
photovisual	4.3	source: 2
photographic	5.3	source: 16

spectral information:

spectral class	K0		source: 96
Morgan-Keenan	K1III		source: 25
B-magnitude	5.4 ±0.05	B-V-magnitude	1.12
U-magnitude	6.37 ±0.05	U-B-magnitude	0.97

variability information:

source of data: 30

variability type	273
var. amplitude	0.16
var. period	19.42
var. epoch	2444677 13. March 1981, 12:00:00 UT
next max light	2452231.38 17. November 2001, 21:07:12 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	182.2 arcsec
magnitude difference between brightest and second brightest component	6.5
position angle	316 °

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
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
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
52	PPMN-HP subset
PPMN Star Catalogue (Reference 16) High-Precision Subset (Code H)
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 40min 11.382sec	DEC: +29° 0' 22.55''	±0.015 arcsec
position (J2000)	RA: 7h 43min 18.737sec	DEC: +28° 53' 0.52''
proper motion B1950 (FK4)	RA: 0.0051 arcsec/a	DEC: -0.234 arcsec/a	±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0049 arcsec/a	DEC: -0.232 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.3 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	K0
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue	GC, catalogue number: 10373
Durchmusterung	BD+29 1590
Boss General Catalogue	10373
Henry Draper Catalogue	62044

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

position and proper motion:

position (J2000)	RA: 7h 43.3min	DEC: +28° 53'
proper motion (J2000)	RA: 0.062 arcsec/a	DEC: -0.232 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
-	1877	2	315°	178.6''	4.28	10.8	K1III	BLL 23
	1909		316°	182.2''

discoverer information:

discoverer code	discoverer	reference
BLL 23	Ball, R.S.	-

notes:

note	Sigma Gem. A is a spectroscopic binary and variable.

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

position:

position (equinox 1950.0)

RA: 7h 40min 11.4sec

DEC: +29° 0' 23''

variability informations:

variability type	RS	eruptive variable star
magnitute at max. brightness	4.13
magnitute at min. brightness	4.29
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2444677.1 13. March 1981, 14:24:00 UT
period [d]	19.423
next maximum light [JD]	2452232.647 19. November 2001, 03:31:41 UT

spectral information

spectral class

K1III

references

to a study	Vol. II GCVS
to a chart/photograph	no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'

miscanellous

ID in the GCVS catalogue	38/9018
constellation	Gemini
notes on existence	The star is equivalent to '0389024 ome'.
There are notes in published catalog.

variability type description

variability type

description

RS

Eruptive variables of the RS Canum Venaticorum type. This type is ascribed to close binary systems with spectra showing Ca II H and K in emission, their components having enhanced chromospheric activity that causes quasi-periodic light variability. The period of variation is close to the orbital one, and the variability amplitude is usually as great as 0.2 mag in V (UX Ari). They are X-ray sources and rotating variables. RS CVn itself is also an eclipsing system.