U Sagitta

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

position, motion, parallax:

position (J2000)	RA: 19h 18min 48.5sec	DEC: +19° 36' 38''
position (B1900)	RA: 19h 14min 25.7sec	DEC: +19° 25' 40''
proper motion (J2000)	RA: 0.022 arcsec/a	DEC: 0.002 arcsec/a
radial velocity	-17 km/s note: spectroscopic binaries note: orbital data avaible
rotational velocity	76 km/s (uncertain) (variable)
galactic coordinates	longitude: 53.44°	latitude: 3.05°

magnitude

visual magnitude

6.58
(V on UBV Johnson system)

spectral / color information

spectral class	B8III+K:
B-V-magnitude	0.03
U-B-magnitude	-0.38

note (category: spectra):

Shell star.

variability information

variable star identification

U Sge

note (category: variability):

EA 6.58 - 9.18V, 3.3806260d. Period varies irregularly. i 90d. Semi-detached system.

double/multiple star system information

separation	92 arcsec
mag difference (of double or brightest multiple)	3
note	Worley (1978) update of the IDS

note (category: spectroscopic binaries):

3.3806d, K 69.7k/s, V0 -10.1k/s, asini 3.24. Alternate orbit 3.3806205d, K 76k/s, V0 -5k/s, asini 3.25.

miscellaneous information

note (category: group membership):

In cluster 4-5 Vul = Collinder 399 (nonmember).

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

position, motion, parallax:

position (J2000)	RA: 19h 18min 48.405sec	DEC: +19° 36' 37.87''	ą0.2 arcsec	source: 52
proper motion (J2000)	RA: 0.0001 arcsec/a	DEC: 0.009 arcsec/a		source: 25
radial velocity	-17 km/s			source: 25
galactic coord. (B1950)	longitude: 53.45°	latitude: 3.05°

magnitude:

visual	6.496 (observed)	source: 31
photographic	6.3	source: 16

spectral information:

spectral class	B9		source: 96
Morgan-Keenan	B8III+K:		source: 25
B-magnitude	6.61 ą0.05	B-V-magnitude	0.03
U-magnitude	6.23 ą0.05	U-B-magnitude	-0.38

variability information:

source of data: 30

variability type	10
var. amplitude	2.83
var. period	3.38
var. epoch	2417130 11. October 1905, 12:00:00 UT
next max light	2452221.16 7. November 2001, 15:50:24 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	0.1 arcsec
position angle	331 °

sources:

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
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
52	PPMN-HP subset
PPMN Star Catalogue (Reference 16) High-Precision Subset (Code H)
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: 19h 16min 37.057sec	DEC: +19° 31' 4.09''	ą0.039 arcsec
position (J2000)	RA: 19h 18min 48.526sec	DEC: +19° 36' 37.59''
proper motion B1950 (FK4)	RA: 0.0015 arcsec/a	DEC: 0.003 arcsec/a	ą0.009 arcsec/a in RA ą0.008 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0016 arcsec/a	DEC: 0.002 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	6.5 (accuracy: 1 decimal)
source of visual magnitude data	Source cited in source catalog introduction.

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

Variable star in visual magnitude in source catalog

catalogues

source catalogue	GC, catalogue number: 26639
Durchmusterung	BD+19 3975
Boss General Catalogue	26639
Henry Draper Catalogue	181182

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

position and proper motion:

position (J2000)	RA: 19h 18.8min	DEC: +19° 37'
proper motion (J2000)	RA: 0 arcsec/a	DEC: 0 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
Aa	1992	1	331°	0.1''	6.6	-	B8III+K	MIU
Aa-B	1875	2	318°	92''	-	9.5	-	AG 432

discoverer information:

discoverer code	discoverer	reference
MIU	Miura, N. et al
AG 432	-	-

notes:

note	A is the eclipsing binary U Sge. Proper motion of B +002 -001.

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

position:

position (equinox 1950.0)

RA: 19h 16min 37.1sec

DEC: +19° 31' 4''

variability informations:

variability type	EA/SD	close binary eclipsing system
magnitute at max. brightness	6.45
magnitute at min. brightness	9.28
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2417130.4114 11. October 1905, 21:52:25 UT
period [d]	3.38061933
next maximum light [JD]	2452221.2400454 7. November 2001, 17:45:40 UT
duration of the eclipse	17 % of period

spectral information

spectral class

B8V+G2IV-III

references

to a study	Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph	Vol. I GCVS (see Kholopov et al. 1985-1988)

miscanellous

ID in the GCVS catalogue	71/4
constellation	Sagitta
notes on existence	The star is equivalent to '0710005 V'.
There are notes in published catalog.

variability type description

variability type	description
EA	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.
SD	Semidetached systems in which the surface of the less massive component is close to its inner Roche lobe.