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	Schedar, a Cas, alf Cas, 18 Cas, HR 168, HD 3712, SAO 21609, BD +55 139, FK5: 21, WDS 00405+5632A
other names	Shedir, Schedir
constellation	Cassiopeia

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

note (category: star names):

SHEDIR; Schedar; Schedir.

position, motion, parallax:

position (J2000)	RA: 0h 40min 30.5sec	DEC: +56° 32' 14''
position (B1900)	RA: 0h 34min 49.7sec	DEC: +55° 59' 20''
proper motion (J2000)	RA: 0.053 arcsec/a	DEC: -0.032 arcsec/a
radial velocity	-4 km/s note: suspected variable radial velocity
rotational velocity	21 km/s (uncertain) (variable)
trigonometric parallax	0.016 arcsec
galactic coordinates	longitude: 121.42°	latitude: -6.3°

magnitude

visual magnitude

2.23 (V on UBV Johnson system)

spectral / color information

spectral class	K0IIIa
B-V-magnitude	1.17
U-B-magnitude	1.13
R-I-magnitude
IR-note	object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

variability information

variable star identification

Alp Cas

note (category: variability):

Cst 2.20 - 2.27V.

double/multiple star system information

number of components of multiple star system	4
separation	64.4 arcsec
mag difference (of double or brightest multiple)	6.7
component ID	AD

note (category: double and multiple data):

D is 8.5v K2IV-V, vsini <54k/s. All components probably optical.

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

position, motion, parallax:

position (J2000)	RA: 0h 40min 30.45sec	DEC: +56° 32' 14.46''	±0.06 arcsec	source: 15
proper motion (J2000)	RA: 0.0064 arcsec/a	DEC: -0.032 arcsec/a		source: 25
radial velocity	-4 km/s			source: 25
trigonometric parallax	0.016 arcsec		±0.002 arcsec	source: 25
galactic coord. (B1950)	longitude: 121.42°	latitude: -6.3°

magnitude:

visual	2.2 (observed)	source: 31
photovisual	2.5	source: 2

spectral information:

spectral class	K0		source: 96
Morgan-Keenan	K0-IIIa		source: 25
B-magnitude	3.4 ±0.05	B-V-magnitude	1.17
U-magnitude	4.53 ±0.05	U-B-magnitude	1.13

variability information:

source of data: 30

variability type	999
var. amplitude	0.07

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	19.8 arcsec
magnitude difference between brightest and second brightest component	11.5
position angle	275 °

component	magnitude	spectral class	catalogue(s)/name(s)
A	2.2	K0	Schedar, a Cassiopeiae, 18 Cas, HR 168, HD 3712, SAO 21609
B	8.784	K0

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: 0h 37min 39.313sec	DEC: +56° 15' 48.6''	±0.003 arcsec
position (J2000)	RA: 0h 40min 30.465sec	DEC: +56° 32' 14.43''
proper motion B1950 (FK4)	RA: 0.0064 arcsec/a	DEC: -0.027 arcsec/a	±0.001 arcsec/a in RA ±0.001 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0065 arcsec/a	DEC: -0.032 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	2.5 (accuracy: 2 decimals)
source of visual magnitude data	Taken from the "Henry Draper Catalogue".

spectral information:

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

catalogues

source catalogue	FK4, catalogue number: 21
Durchmusterung	BD+55 139
Boss General Catalogue	792
Henry Draper Catalogue	3712

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

position and proper motion:

position (J2000)	RA: 0h 40.5min	DEC: +56° 32'
proper motion (J2000)	RA: 0.053 arcsec/a	DEC: -0.032 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
AB	1889	2	272°	17.6''	2.5	14	K0IIIa	BU 1349
	1934		275°	19.8''
AC	1878	4	109°	40.1''	2.5	13	-	BU 1349
	1908		105°	38.3''
AD	1781	11	275°	56.2''	2.5	8.5	-	H 18
	1913		280°	64.4''

discoverer information:

discoverer code	discoverer	reference
BU 1349	Burnham, S.W.	-
H 18	Herschel, W.	-

notes:

note	Alpha Cas. AD: H V 18. Also HJ 1993.

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

position:

position (equinox 1950.0)

RA: 0h 37min 39.3sec

DEC: +56° 15' 49''

variability informations:

variability type	CST:
magnitute at max. brightness	2.2
magnitute at min. brightness	2.27
photometric system	visual, photovisual or Johnson's V

spectral information

spectral class

K0IIIa

references

to a chart/photograph

no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'

miscanellous

ID in the GCVS catalogue	18/9001
constellation	Cassiopeia
notes on existence	The star is equivalent to '0189002 bet'.
There are notes in published catalog.

variability type description

variability type	description
CST	Nonvariable stars, formerly suspected to be variable and hastily designated. Further observations have not confirmed their variability.