EY Canis Majoris

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

note (category: star names):

Old sources call this Pi1 CMa, HR 2558 Pi2 and HR 2590 Pi3. Superscripts no longer retained.

position, motion, parallax:

position (J2000)	RA: 6h 53min 32.9sec	DEC: -20° 13' 27''
position (2000.72)	RA: 6h 53min 35sec	DEC: -20° 13' 30''
position (B1900)	RA: 6h 49min 13.4sec	DEC: -20° 6' 2''
proper motion (J2000)	RA: -0.009 arcsec/a	DEC: 0.004 arcsec/a
radial velocity	28 km/s note: variable radial velocity
rotational velocity	49 km/s (uncertain) (variable)
galactic coordinates	longitude: 231.3°	latitude: -8.62°

note (category: radial and/or rotational velocities):

0.184558d.

magnitude

visual magnitude

4.83
(V on UBV Johnson system)

spectral / color information

spectral class	B1IV
B-V-magnitude	-0.21
U-B-magnitude	-0.96
R-I-magnitude

variability information

variable star identification

EY CMa

note (category: variability):

Beta C 4.60 - 4.63B, 0.184557 and 0.19296d, beat per. about 2d.

miscellaneous information

note (category: group membership):

Probable member Collinder 121 (#24); OB group near Omicron CMa.

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

position, motion, parallax:

position (J2000)	RA: 6h 53min 32.893sec	DEC: -20° 13' 27.41''	ą0.22 arcsec	source: 15
position (2000.72)	RA: 6h 53min 35sec	DEC: -20° 13' 30''	JD: 2451809.23
proper motion (J2000)	RA: -0.0007 arcsec/a	DEC: 0.004 arcsec/a		source: 25
radial velocity	28 km/s			source: 25
galactic coord. (B1950)	longitude: 231.31°	latitude: -8.62°

magnitude:

visual	4.83 (observed)	source: 25
photovisual	4.7	source: 2
photographic	4.4	source: 2

spectral information:

spectral class	B1		source: 96
Morgan-Keenan	B1IV		source: 25
B-magnitude	4.62 ą0.05	B-V-magnitude	-0.21
U-magnitude	3.66 ą0.05	U-B-magnitude	-0.96

variability information:

source of data: 30

variability type	140
var. amplitude	0.05
var. period	0.18
var. epoch	2441296 10. December 1971, 12:00:00 UT
next max light	2451809.26 21. September 2000, 18:14:24 UT

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
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: 6h 51min 23.118sec	DEC: -20° 9' 40.03''	ą0.023 arcsec
position (2000.72)	RA: 6h 53min 35sec	DEC: -20° 13' 31''	JD: 2451809.23
position (J2000)	RA: 6h 53min 32.899sec	DEC: -20° 13' 27.18''
proper motion B1950 (FK4)	RA: -0.0009 arcsec/a	DEC: 0.003 arcsec/a	ą0.004 arcsec/a in RA ą0.004 arcsec/a in DEC
proper motion J2000 (FK5)	RA: -0.0005 arcsec/a	DEC: 0.005 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	B1
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue	GC, catalogue number: 9034
Durchmusterung	BD-20 1616
Boss General Catalogue	9034
Henry Draper Catalogue	50707

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

position:

position (equinox 1950.0)

RA: 6h 51min 23.1sec

DEC: -20° 9' 40''

variability informations:

variability type	BCEP	pulsating variable star
magnitute at max. brightness	4.79
magnitute at min. brightness	4.84
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2441296.164 10. December 1971, 15:56:10 UT
period [d]	0.184557
next maximum light [JD]	2451809.268948 21. September 2000, 18:27:17 UT
rising time	50 % of period

spectral information

spectral class

B1III-IV

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	14/168
constellation	Canis Major
notes on existence	The star is equivalent to '0140169 EZ'.
There are notes in published catalog.

variability type description

variability type

description

BCEP

Variables of the Beta Cephei type (Beta Cep, Beta CMa), which are pulsating O8-B6 I-V stars with periods of light and radial-velocity variations in the range of 0.1 - 0.6 days and light amplitudes from 0.01 to 0.3 mag in V. The light curves are similar in shape to average radial-velocity curves but lag in phase by a quarter of the period, so that maximum brightness corresponds to
maximum contraction, i.e., to minimum stellar radius. The majority of these stars probably show radial pulsations, but some (V649 Per) display nonradial pulsations; multiperiodicity is characteristic of many of these stars.

catalogues and names	EY CMa, 15 CMa, HR 2571, HD 50707, SAO 172520, BD -20 1616, FK5: 2532
constellation	Canis Major