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	EN Eri, 66 Eri, HR 1657, HD 32964, SAO 131777, BD -4 1044, WDS 05068-0439
constellation	Eridanus

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

position, motion, parallax:

position (J2000)	RA: 5h 6min 45.7sec	DEC: -4° 39' 18''
position (B1900)	RA: 5h 1min 48.9sec	DEC: -4° 47' 21''
proper motion (J2000)	RA: 0.016 arcsec/a	DEC: 0.008 arcsec/a
radial velocity	31 km/s note: spectroscopic binaries, double lined spectra note: orbital data avaible
rotational velocity	=<41 km/s (uncertain) (variable)
trigonometric parallax	0.024 arcsec
galactic coordinates	longitude: 204.78°	latitude: -25.35°

magnitude

visual magnitude

5.12 (V on UBV Johnson system)

spectral / color information

spectral class	B9V+A1V
B-V-magnitude	-0.06
U-B-magnitude	-0.17
R-I-magnitude

variability information

variable star identification

1831

note (category: variability):

E? 5.1 - 5.6v. About 2d.

double/multiple star system information

separation	52.8 arcsec
mag difference (of double or brightest multiple)	5.4

note (category: spectroscopic binaries):

B9.5, B9.5, 5.5227d, K 103.8k/s, V0 +32.6k/s, msin3i 2.38, asini 7.85. Nearly equal components; secondary is the more massive, a mercury star. vsini of both components =<41k/s.

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

position, motion, parallax:

position (J2000)	RA: 5h 6min 45.628sec	DEC: -4° 39' 18.89''	±0.19 arcsec	source: 16
proper motion (J2000)	RA: -0.0002 arcsec/a	DEC: -0.006 arcsec/a		source: 25
radial velocity	31 km/s			source: 25
trigonometric parallax	0.024 arcsec		±0.002 arcsec	source: 25
galactic coord. (B1950)	longitude: 204.78°	latitude: -25.35°

magnitude:

visual	5.12 (observed)	source: 25
photovisual	5	source: 16
photographic	5.2	source: 2

spectral information:

spectral class	B9		source: 96
Morgan-Keenan	B9V+A1V		source: 25
B-magnitude	5.06 ±0.05	B-V-magnitude	-0.06
U-magnitude	4.89 ±0.05	U-B-magnitude	-0.17

variability information:

source of data: 27

variability type	160
var. amplitude	0

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	52.8 arcsec
magnitude difference between brightest and second brightest component	5.6
position angle	10 °

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
27	Catalog of Red Magnitudes (CRM)
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: 5h 4min 17.22sec	DEC: -4° 43' 13.98''	±0.021 arcsec
position (J2000)	RA: 5h 6min 45.692sec	DEC: -4° 39' 17.52''
proper motion B1950 (FK4)	RA: 0.0007 arcsec/a	DEC: 0.009 arcsec/a	±0.004 arcsec/a in RA ±0.003 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0011 arcsec/a	DEC: 0.008 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	5.2 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	B9
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: 6246
Durchmusterung	BD-04 1044
Boss General Catalogue	6246
Henry Draper Catalogue	32964

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

position and proper motion:

position (J2000)	RA: 5h 6.8min	DEC: -4° 39'
proper motion (J2000)	RA: 0.007 arcsec/a	DEC: -0.009 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
-	1879	7	10°	52.8''	5.12	10.7	B9V+A1V	STF 642

discoverer information:

discoverer code	discoverer	reference
STF 642	Struve, F.G.W.	-

notes:

note	66 Eri. A is a spectroscopic binary.

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

position:

position (equinox 1950.0)

RA: 5h 4min 17.2sec

DEC: -4° 43' 14''

variability informations:

variability type	ACV:	rotating variable star
magnitute at max. brightness	4.89
magnitute amplitude	0.01
photometric system

references

to a study	H.Schneider, Hvar Obs Bull 11,No.1,29,1987.
to a chart/photograph	no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'

miscanellous

ID in the GCVS catalogue	36/157
constellation	Eridanus
notes on existence	The star is equivalent to '70047'.

variability type description

variability type

description

ACV

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. ACVO 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.