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	e Cap, eps Cap, 39 Cap, HR 8260, HD 205637, SAO 164520, BD -20 6251, FK5: 3724, WDS 21371-1928A
constellation	Capricornus

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

position, motion, parallax:

position (J2000)	RA: 21h 37min 4.8sec	DEC: -19° 27' 58''
position (B1900)	RA: 21h 31min 28.9sec	DEC: -19° 54' 51''
proper motion (J2000)	RA: 0.015 arcsec/a	DEC: 0.003 arcsec/a
radial velocity	-24 km/s note: spectroscopic binaries
rotational velocity	293 km/s (uncertain) (variable)
galactic coordinates	longitude: 31.94°	latitude: -44.99°

magnitude

visual magnitude

4.68 (V on UBV Johnson system)

spectral / color information

spectral class	B2.5Vpe
B-V-magnitude	-0.17
U-B-magnitude	-0.65
R-I-magnitude

note (category: spectra):

Shell star. Shell spectrum resembles supergiant A-type with vsini 50k/s. Also classified B3IIIe.

variability information

variable star identification

Eps Cap

note (category: variability):

Gamma Cas 4.44 - 4.72V. Polarization variable. Slight variation in H alpha line width.

double/multiple star system information

number of components of multiple star system	3
separation	0 arcsec
mag difference (of double or brightest multiple)	1.3
note	Worley (1978) update of the IDS

note (category: double and multiple data):

Component A is SB, 5.0, 6.3v, 0.0047"; component B, 9.5v K1III-IV: at 68", physical, vsini =<54k/s.

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

position, motion, parallax:

position (J2000)	RA: 21h 37min 4.84sec	DEC: -19° 27' 57.53''	±0.22 arcsec	source: 15
proper motion (J2000)	RA: 0.0011 arcsec/a	DEC: 0.003 arcsec/a		source: 25
radial velocity	-24 km/s			source: 25
galactic coord. (B1950)	longitude: 31.95°	latitude: -44.99°

magnitude:

visual	4.48 (observed)	source: 30
photovisual	4.7	source: 2
photographic	4.6	source: 2

spectral information:

spectral class	B5		source: 96
Morgan-Keenan	B2.5Vpe		source: 25
B-magnitude	4.51 ±0.05	B-V-magnitude	-0.17
U-magnitude	3.86 ±0.05	U-B-magnitude	-0.65

variability information:

source of data: 30

variability type	264
var. amplitude	0.24

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	68.1 arcsec
magnitude difference between brightest and second brightest component	4.88
position angle	47 °

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
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: 21h 34min 17.002sec	DEC: -19° 41' 27.69''	±0.01 arcsec
position (J2000)	RA: 21h 37min 4.815sec	DEC: -19° 27' 57.42''
proper motion B1950 (FK4)	RA: 0.0007 arcsec/a	DEC: 0.006 arcsec/a	±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0008 arcsec/a	DEC: 0.003 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.7 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	B5p
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Double star in Aitken's Double Star Catalogue (Aitken 1932)

catalogues

source catalogue	GC, catalogue number: 30252
Durchmusterung	BD-20 6251
Boss General Catalogue	30252
Henry Draper Catalogue	205637

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

position and proper motion:

position (J2000)	RA: 21h 37.1min	DEC: -19° 28'
proper motion (J2000)	RA: 0.015 arcsec/a	DEC: 0.003 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	10	47°	68.1''	4.64	9.52	B2.5Vpe	H 6

discoverer information:

discoverer code	discoverer	reference
H 6	Herschel, W.	-

notes:

note	H VI 6. Epsilon Cap. A is a Cepheid and shell star. It is also an occultation double. B is BD-20@6253.

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

position:

position (equinox 1950.0)

RA: 21h 34min 17sec

DEC: -19° 41' 28''

variability informations:

variability type	GCAS	eruptive variable star
magnitute at max. brightness	4.48
magnitute at min. brightness	4.72
photometric system	visual, photovisual or Johnson's V

spectral information

spectral class

B3IV-Vpeq

references

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'

miscanellous

ID in the GCVS catalogue	16/9005
constellation	Capricornus
notes on existence	The star is equivalent to '0169009 iot'.
There are notes in published catalog.

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.