ER Vulpeculae

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

position, motion, parallax:

position (J2000)	RA: 21h 2min 25.908sec	DEC: +27° 48' 26.39''	ą0.43 arcsec	source: 16
position (2000.73)	RA: 21h 2min 28sec	DEC: +27° 48' 36''	JD: 2451810.12
proper motion (J2000)	RA: 0.0067 arcsec/a	DEC: 0.005 arcsec/a		source: 16
radial velocity	-26 km/s			source: 11
galactic coord. (B1950)	longitude: 73.35°	latitude: -12.3°

magnitude:

visual	7.3 (observed)	source: 31
photovisual	7.2	source: 2
photographic	7.8	source: 16

spectral information:

spectral class	G0		source: 96
Morgan-Keenan	G0III		source: 98
B-magnitude	7.92 ą0.02	B-V-magnitude	0.62
U-magnitude	7.99 ą0.02	U-B-magnitude	0.07

variability information:

source of data: 30

variability type	10
var. amplitude	0.22
var. period	0.7
var. epoch	2440182 21. November 1968, 12:00:00 UT
next max light	2451810.4 22. September 2000, 21:36:00 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
11	General Catalogue of Stellar Radial Velocities
Wilson, R.E., General Catalogue of Stellar of Stellar Radial Radial Velocities, Washington, DC: Carnegie Institute of Washington, 1953
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
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
98	SKYMAP Master Catalog Version 3.7
Reference from Value 97 [original data sources Catalog Version 3.7 are identified in SKYMAP Version 3.7]

data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)

position and proper motion:

position (B1950)	RA: 21h 0min 16.429sec	DEC: +27° 36' 33.36''	ą0.025 arcsec
position (2000.73)	RA: 21h 2min 27sec	DEC: +27° 48' 36''	JD: 2451810.12
position (J2000)	RA: 21h 2min 25.858sec	DEC: +27° 48' 26.3''
proper motion B1950 (FK4)	RA: 0.0062 arcsec/a	DEC: 0.007 arcsec/a	ą0.011 arcsec/a in RA ą0.008 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0063 arcsec/a	DEC: 0.004 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	7.5 (accuracy: 1 decimal)
source of visual magnitude data	Taken from AGK1.
photographic	8.1 (accuracy: 2 decimals)
source of photographic magnitude data	Determined by source catalog.

spectral information:

spectral class	G0
source of spectral data	Taken from the HD with M stars reclassified by Miss Cannon.

catalogues

source catalogue	Yale Transactions 24, catalogue number: 12031
Durchmusterung	BD+27 3952
Henry Draper Catalogue	200391

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

position:

position (equinox 1950.0)

RA: 21h 0min 16.4sec

DEC: +27° 36' 33''

variability informations:

variability type	EW/DW/RS	close binary eclipsing system eruptive variable star
magnitute at max. brightness	7.27
magnitute at min. brightness	7.49
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2440182.2621 21. November 1968, 18:17:25 UT
period [d]	0.69809409
next maximum light [JD]	2451810.41535713 22. September 2000, 21:58:07 UT

spectral information

spectral class

G0V+G5V

references

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

miscanellous

ID in the GCVS catalogue	88/161
constellation	Vulpecula
notes on existence	The star is equivalent to '0880162 ES'.
There are notes in published catalog.

variability type description

variability type	description
EW	Eclipsing binary systems. These are binary systems with orbital planes so close to the observer's line of sight (the inclination i of the orbital plane to the plane orthogonal to the line of sight is close to 90 deg) that the components periodically eclipse each other. Consequently, the observer finds changes of the apparent combined brightness of the system with the period coincident with that of the components' orbital motion. EA Algol (Beta Persei)-type eclipsing systems. Binaries with spherical or slightly ellipsoidal components. It is possible to specify, for their light curves, the moments of the beginning and end of the eclipses. Between eclipses the light remains almost constant or varies insignificantly because of reflection effects, slight ellipsoidality of components, or physical variations. Secondary minima may be absent. An extremely wide range of periods is observed, from 0.2 to >= 10000 days. Light amplitudes are also quite different and may reach several magnitudes. EB Beta Lyrae-type eclipsing systems. These are eclipsing systems having ellipsoidal components and light curves for which it is impossible to specify the exact times of onset and end of eclipses because of a continuous change of a system's apparent combined brightness between eclipses; secondary minimum is observed in all cases, its depth usually being considerably smaller than that of the primary minimum; periods are mainly longer than 1 day. The components generally belong to early spectral types (B-A). Light amplitudes are usually <2 mag in V. EW W Ursae Majoris-type eclipsing variables. These are eclipsers with periods shorter than 1 days, consisting of ellipsoidal components almost in contact and having light curves for which it is impossible to specify the exact times of onset and end of eclipses. The depths of the primary and secondary minima are almost equal or differ insignificantly. Light amplitudes are usually <0.8 mag in V. The components generally belong to spectral types F-G and later.
DW	Systems similar to W UMa systems in physical properties (KW, see below), but not in contact.
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.