g1Sagittarii
| catalogues and names | g1Sgr, W Sgr, HR 6742, HD 164975, SAO 186237, 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 (J1900) | 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) | |
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 | 0,45 |
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 |
| 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° | ||
| GCI unit vector (J2000) | X: 0,019049 | Y: -0,869458 | Z: -0,493639 | |
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:
| variability type | 111 |
| var. amplitude | 0,85 |
| var. period | 7,6 |
| var. epoch | 2443375 19. August 1977, 12:00:00 UT |
| next max light | 2451628,6 25. March 2000, 02:24:00 UT |
double/multiple star system information:
| 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 (J1950) | RA: 18h 1min 49,519sec | DEC: -29° 35' 3,04'' | ±0,021 arcsec |
| position (J2000) | RA: 18h 5min 1,277sec | DEC: -29° 34' 48,09'' | |
| proper motion J1950 (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 (J1950) | 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] | 2451622,97258 19. March 2000, 11:20:31 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 | Scorpius |
| 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. |