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	g1Sgr, W Sgr, HR 6742, HD 164975, SAO 186237, CD -29 14447, WDS 18050-2935A
constellation	Sagittarius

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

note (category: star names):

Although HR 6742 and 6746 are named gamma1 and gamma2 Sgr, respectively, more often 6746 is simply called gamma Sgr and the Greek letter is omitted for HR 6742.

position, motion, parallax:

position (J2000)	RA: 18h 5min 1.3sec	DEC: -29° 34' 48''
position (2000.72)	RA: 18h 5min 4sec	DEC: -29° 34' 48''
position (B1900)	RA: 17h 58min 37.9sec	DEC: -29° 35' 4''
proper motion (J2000)	RA: 0.013 arcsec/a	DEC: 0 arcsec/a
radial velocity	-28 km/s note: spectroscopic binaries note: orbital data avaible
rotational velocity	25 km/s (uncertain) (variable)
galactic coordinates	longitude: 1.58°	latitude: -3.98°

magnitude

visual magnitude

4.69 (V on UBV Johnson system)

spectral / color information

spectral class	F4-G1Ib
B-V-magnitude	0.78
U-B-magnitude	0.52
R-I-magnitude

variability information

variable star identification

W Sgr

note (category: variability):

ADS 11029A, CDelta 4.30 - 5.08V, 7.594710d. Period changes. Spectrum and magnetic field variable. One component of SB.

double/multiple star system information

number of components of multiple star system	4
separation	0.1 arcsec
mag difference (of double or brightest multiple)	0

note (category: double and multiple data):

ADS 11029A is speckle interferometric double, sep. 0.116". Visual companions, 13.5v at 33" and 13.5v at 48".

note (category: spectroscopic binaries):

80y, K 2.65k/s, V0 -27.7k/s, asini 60.

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

position, motion, parallax:

position (J2000)	RA: 18h 5min 1.222sec	DEC: -29° 34' 48.25''	±0.19 arcsec	source: 16
position (2000.72)	RA: 18h 5min 4sec	DEC: -29° 34' 48''	JD: 2451806.24
proper motion (J2000)	RA: 0 arcsec/a	DEC: -0.001 arcsec/a		source: 25
radial velocity	-28 km/s			source: 25
galactic coord. (B1950)	longitude: 1.58°	latitude: -3.98°

magnitude:

visual	4.29 (observed)	source: 30
photovisual	4.7	source: 16

spectral information:

spectral class	F8		source: 96
Morgan-Keenan	F4-G1Ib		source: 25
B-magnitude	5.47 ±0.05	B-V-magnitude	0.78
U-magnitude	5.99 ±0.05	U-B-magnitude	0.52

variability information:

source of data: 30

variability type	111
var. amplitude	0.85
var. period	7.6
var. epoch	2443375 19. August 1977, 12:00:00 UT
next max light	2451811 23. September 2000, 12:00:00 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	0.1 arcsec
position angle	153 °

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
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 1min 49.519sec	DEC: -29° 35' 3.04''	±0.021 arcsec
position (2000.72)	RA: 18h 5min 4sec	DEC: -29° 34' 48''	JD: 2451806.24
position (J2000)	RA: 18h 5min 1.277sec	DEC: -29° 34' 48.09''
proper motion B1950 (FK4)	RA: 0.0011 arcsec/a	DEC: -0.001 arcsec/a	±0.004 arcsec/a in RA ±0.004 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.001 arcsec/a	DEC: 0 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.3 (accuracy: 1 decimal)
source of visual magnitude data	Source cited in source catalog introduction.

spectral information:

spectral class	F8p
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: 24605
Durchmusterung	CD-2914447
Boss General Catalogue	24605
Henry Draper Catalogue	164975

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

position and proper motion:

position (J2000)	RA: 18h 5min	DEC: -29° 35'
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
Aa	1976	1	153°	0.1''	-	-	F4-G1Ib	BLM
Aa-B	1897	2	234°	32.9''	-	13.5	-	SEE 346
Aa-C	1897	2	100°	47.8''	-	13.5	-	SEE 346

discoverer information:

discoverer code	discoverer	reference
BLM	Morgan, B. et al
SEE 346	See, T.J.	-

notes:

note	Gamma (1) Sgr. A is the Cepheid W Sgr, spectrum also variable. It is a long-period spectroscopic binary and speckle and occultation pair.

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

position:

position (equinox 1950.0)

RA: 18h 1min 49.5sec

DEC: -29° 35' 3''

variability informations:

variability type	DCEP	pulsating variable star
magnitute at max. brightness	4.29
magnitute at min. brightness	5.14
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2443374.77 19. August 1977, 06:28:48 UT
period [d]	7.59503
next maximum light [JD]	2451812.84833 25. September 2000, 08:21:36 UT
rising time	32 % of period

spectral information

spectral class

F4-G2Ib

references

to a study	the main characteristics of the star was determined by the authors themselves
to a chart/photograph	Vol. I GCVS (see Kholopov et al. 1985-1988)

miscanellous

ID in the GCVS catalogue	72/6
constellation	Sagittarius
notes on existence	The star is equivalent to '0720007 X'.
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.