U Aquilae

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

position, motion, parallax:

position (J2000)	RA: 19h 29min 21.5sec	DEC: -7° 2' 38''
position (2000.72)	RA: 19h 29min 24sec	DEC: -7° 2' 33''
position (B1900)	RA: 19h 23min 58.4sec	DEC: -7° 14' 58''
proper motion (J2000)	RA: 0.024 arcsec/a	DEC: 0.003 arcsec/a
radial velocity	-7 km/s note: variable radial velocity
trigonometric parallax	0.013 arcsec
galactic coordinates	longitude: 30.91°	latitude: -11.62°

magnitude

visual magnitude

6.61
(V on UBV Johnson system)

spectral / color information

spectral class	F7-G1I-II
B-V-magnitude	1.1
U-B-magnitude	0.7
R-I-magnitude

note (category: spectra):

Also classified F5I-II-G1.

variability information

variable star identification

U Aql

note (category: variability):

ADS 12503A, CDelta 6.08 - 6.86V, 7.02393d. Period changes.

double/multiple star system information

number of components of multiple star system	3
separation	1.5 arcsec
mag difference (of double or brightest multiple)	5.5
component ID	AB

note (category: double and multiple data):

AB fixed. C, 7v at 2", binary.

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

position, motion, parallax:

position (J2000)	RA: 19h 29min 21.382sec	DEC: -7° 2' 38.78''	ą0.19 arcsec	source: 16
position (2000.72)	RA: 19h 29min 23sec	DEC: -7° 2' 34''	JD: 2451806.24
proper motion (J2000)	RA: 0.0005 arcsec/a	DEC: -0.006 arcsec/a		source: 25
radial velocity	1 km/s			source: 25
trigonometric parallax	0.013 arcsec		ą0.001 arcsec	source: 25
galactic coord. (B1950)	longitude: 30.91°	latitude: -11.62°

magnitude:

visual	6.1 (observed)	source: 31
photovisual	6.7	source: 16

spectral information:

spectral class	F8		source: 96
Morgan-Keenan	F7-G1I-II		source: 25
B-magnitude	7.71 ą0.05	B-V-magnitude	1.1
U-magnitude	8.41 ą0.05	U-B-magnitude	0.7

variability information:

source of data: 30

variability type	111
var. amplitude	0.78
var. period	7.02
var. epoch	2434922 28. June 1954, 12:00:00 UT
next max light	2451812.12 24. September 2000, 14:52:48 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	1.6 arcsec
position angle	230 °

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
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 26min 39.93sec	DEC: -7° 8' 53.4''	ą0.059 arcsec
position (2000.72)	RA: 19h 29min 24sec	DEC: -7° 2' 32''	JD: 2451806.24
position (J2000)	RA: 19h 29min 21.509sec	DEC: -7° 2' 37.73''
proper motion B1950 (FK4)	RA: 0.0014 arcsec/a	DEC: 0.003 arcsec/a	ą0.011 arcsec/a in RA ą0.011 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0016 arcsec/a	DEC: 0.003 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	6.3 (accuracy: 1 decimal)
source of visual magnitude data	Source cited in source catalog introduction.

spectral information:

spectral class	G4v
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: 26905
Durchmusterung	BD-07 4968
Boss General Catalogue	26905
Henry Draper Catalogue	183344

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

position and proper motion:

position (J2000)	RA: 19h 29.4min	DEC: -7° 3'
proper motion (J2000)	RA: 0.004 arcsec/a	DEC: -0.008 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	1934	3	230°	1.6''	-	11.7	F7-G1I-II	KUI 91
AC	1900	3	348°	35.2''	-	14	-	HJ 887

discoverer information:

discoverer code	discoverer	reference
KUI 91	Kuiper, G.P.	-
HJ 887	Herschel, J.	-

notes:

note	A is the Cepheid U Aql.

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

position:

position (equinox 1950.0)

RA: 19h 26min 39.9sec

DEC: -7° 8' 53''

variability informations:

variability type	DCEP	pulsating variable star
magnitute at max. brightness	6.08
magnitute at min. brightness	6.86
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2434922.31 28. June 1954, 19:26:24 UT
period [d]	7.02393
next maximum light [JD]	2451807.83772 20. September 2000, 08:06:19 UT
rising time	30 % of period

spectral information

spectral class

F5I-II-G1

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	5/4
constellation	Aquila
notes on existence	The star is equivalent to '0050005 V'.
There are notes in published catalog.

variability type description

variability type

description

DCEP

These are the classical cepheids, or Delta Cep-type variables. Comparatively young objects that have left the main sequence and evolved into the instability strip of the Hertzsprung-Russell (H-R) diagram, they obey the well-known Cepheid period-luminosity relation and belong to the young disk population. DCEP stars are present in open clusters. They display a certain relation between the shapes of their light curves and their periods.