catalogues and names

The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

SKY2000 - Master Star Catalog

Smithsonian Astrophysical Observatory Star Catalog

The Washington Visual Double Star Catalog, 1996.0

Combined General Catalogue of Variable Stars (Vol. I-III)

catalogues and names

catalogues and names	s Aql, sig Aql, 44 Aql, HR 7474, HD 185507, SAO 124903, BD +5 4225, WDS 19392+0524
constellation	Aquila

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

position, motion, parallax:

position (J2000)	RA: 19h 39min 11.6sec	DEC: +5° 23' 52''
position (2000.73)	RA: 19h 39min 14sec	DEC: +5° 23' 58''
position (B1900)	RA: 19h 34min 15.5sec	DEC: +5° 10' 11''
proper motion (J2000)	RA: 0.001 arcsec/a	DEC: -0.001 arcsec/a
radial velocity	-5 km/s note: spectroscopic binaries note: orbital data avaible
rotational velocity	121 km/s (uncertain) (variable)
galactic coordinates	longitude: 43.27°	latitude: -8.07°

magnitude

visual magnitude

5.17 (V on UBV Johnson system)

spectral / color information

spectral class	B3V+B3V
B-V-magnitude	0.03
U-B-magnitude	-0.6

variability information

variable star identification

Sig Aql

note (category: variability):

ADS 12737A, EB 5.18 - 5.36B, 1.95026827d. i 71.7d. Spectra vary in period 1.950271d.

double/multiple star system information

number of components of multiple star system	3
separation	47.8 arcsec
mag difference (of double or brightest multiple)	6.6
component ID	AB

note (category: double and multiple data):

B, 12v K0Ve at 48" optical. C, 12v at 130". Rotational velocity of A 123k/s, of B 142k/s.

note (category: spectroscopic binaries):

ADS 12737A, 1.950271d, K 164.2k/s, V0 -4.5k/s, msin3i 5.84, asini 4.40. vsini of secondary 129k/s.

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

position, motion, parallax:

position (J2000)	RA: 19h 39min 11.614sec	DEC: +5° 23' 52.02''	±0.2 arcsec	source: 52
position (2000.73)	RA: 19h 39min 14sec	DEC: +5° 23' 58''	JD: 2451810.11
proper motion (J2000)	RA: -0.0004 arcsec/a	DEC: -0.007 arcsec/a		source: 25
radial velocity	-5 km/s			source: 25
galactic coord. (B1950)	longitude: 43.27°	latitude: -8.07°

magnitude:

visual	5.1 (observed)	source: 31
photovisual	5.2	source: 2
photographic	5.1	source: 16

spectral information:

spectral class	B3		source: 96
Morgan-Keenan	B3V+B3V		source: 25
B-magnitude	5.2 ±0.05	B-V-magnitude	0.03
U-magnitude	4.6 ±0.05	U-B-magnitude	-0.6

variability information:

source of data: 30

variability type	10
var. amplitude	0.2
var. period	1.95
var. epoch	2422487 11. June 1920, 12:00:00 UT
next max light	2451811.1 23. September 2000, 14:24:00 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	47.8 arcsec
magnitude difference between brightest and second brightest component	7.11
position angle	328 °

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
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 36min 43.517sec	DEC: +5° 16' 56.88''	±0.012 arcsec
position (2000.73)	RA: 19h 39min 14sec	DEC: +5° 23' 59''	JD: 2451810.11
position (J2000)	RA: 19h 39min 11.62sec	DEC: +5° 23' 52.28''
proper motion B1950 (FK4)	RA: -0.0001 arcsec/a	DEC: 0.001 arcsec/a	±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0001 arcsec/a	DEC: -0.001 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	5.2 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	B3
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Double star in Aitken's Double Star Catalogue (Aitken 1932)

catalogues

source catalogue	GC, catalogue number: 27185
Durchmusterung	BD+05 4225
Boss General Catalogue	27185
Henry Draper Catalogue	185507

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

position and proper motion:

position (J2000)	RA: 19h 39.2min	DEC: +5° 24'
proper motion (J2000)	RA: 0.004 arcsec/a	DEC: -0.003 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
-	1903	4	328°	47.8''	5.22	12.33	B3V+B3V	HJ 2886

discoverer information:

discoverer code	discoverer	reference
HJ 2886	Herschel, J.	-

notes:

note	Sigma Aql. A is a Beta Lyrae-type system, spectrum composite. Spectrum of B G8V.

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

position:

position (equinox 1950.0)

RA: 19h 36min 43.5sec

DEC: +5° 16' 57''

variability informations:

variability type	EB/DM	close binary eclipsing system
magnitute at max. brightness	5.14
magnitute amplitude	0.2
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2422486.797 11. June 1920, 07:07:41 UT
period [d]	1.95026
next maximum light [JD]	2451810.90636 23. September 2000, 09:45:10 UT

spectral information

spectral class

B3V+B3V

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	5/9018
constellation	Aquila
notes on existence	The star is equivalent to '0060001 R'.
There are notes in published catalog.

variability type description

variability type	description
EB	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.
DM	Detached main-sequence systems. Both components are main-sequence stars and do not fill their inner Roche lobes.