Deneb el Okab

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

note (category: star names):

Deneb el Okab; Deneb. Names combined with HR 7235.

position, motion, parallax:

position (J2000)	RA: 18h 59min 37.4sec	DEC: +15° 4' 6''
position (B1900)	RA: 18h 55min 5sec	DEC: +14° 55' 57''
proper motion (J2000)	RA: -0.051 arcsec/a	DEC: -0.073 arcsec/a
radial velocity	-48 km/s note: spectroscopic binaries
rotational velocity	<17 km/s (uncertain) (variable)
trigonometric parallax	0.028 arcsec
galactic coordinates	longitude: 47.3°	latitude: 5.04°

magnitude

visual magnitude

4.02
(V on UBV Johnson system)

spectral / color information

spectral class	K1-IIICN0.5Ba0.2
B-V-magnitude	1.08
U-B-magnitude	1.04
R-I-magnitude
IR-note	object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

note (category: colors):

V magnitudes scatter from 5.56 to 5.81, B-V from +0.35 to +0.45, U-B from -0.01 to +0.04.

double/multiple star system information

number of components of multiple star system	3
separation	131.1 arcsec
mag difference (of double or brightest multiple)	5.9
component ID	AB
note	Worley (1978) update of the IDS

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

position, motion, parallax:

magnitude:

visual	4.02 (observed)	source: 25
photovisual	4.2	source: 2

spectral information:

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	130.5 arcsec
magnitude difference between brightest and second brightest component	5.9
position angle	186 °

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
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: 18h 57min 21.119sec	DEC: +14° 59' 56.41''	±0.004 arcsec
position (J2000)	RA: 18h 59min 37.363sec	DEC: +15° 4' 5.76''
proper motion B1950 (FK4)	RA: -0.0036 arcsec/a	DEC: -0.073 arcsec/a	±0.001 arcsec/a in RA ±0.001 arcsec/a in DEC
proper motion J2000 (FK5)	RA: -0.0035 arcsec/a	DEC: -0.074 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.2 (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

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

position and proper motion:

position (J2000)	RA: 18h 59.6min	DEC: +15° 4'
proper motion (J2000)	RA: -0.051 arcsec/a	DEC: -0.073 arcsec/a

double/multiple star system information:

discoverer information:

discoverer code	discoverer	reference
ENG 65	Engelmann, R.	-

notes:

note	Epsilon Aql. A is a spectroscopic binary. Spectral type K1IIICN0.5Ba0.2.

catalogues and names	Deneb el Okab, e Aql, 13 Aql, HR 7176, HD 176411, SAO 104318, BD +14 3736, FK5: 712, WDS 18596+1504A
constellation	Aquila