Sham
| catalogues and names | Sham, a Sge, 5 Sge, HR 7479, HD 185758, SAO 105120, WDS 19401+1801A |
| other names | Alsahm |
| constellation | Sagitta |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Sham; Alsahm. Names originally corresponded to whole constellation Sagitta. |
position, motion, parallax:
| position (J2000) | RA: 19h 40min 5,8sec | DEC: +18° 0' 50'' |
| position (J1900) | RA: 19h 35min 37,5sec | DEC: +17° 47' 2'' |
| proper motion (J2000) | RA: 0,014 arcsec/a | DEC: -0,021 arcsec/a |
| radial velocity | 2 km/s note: suspected variable radial velocity |
|
| rotational velocity | 0 km/s (uncertain) (variable) | |
magnitude
| visual magnitude | 4,37 (V on UBV Johnson system) |
spectral / color information
| spectral class | G1II |
| B-V-magnitude | 0,78 |
| U-B-magnitude | 0,43 |
| R-I-magnitude | 0,37 |
double/multiple star system information
| number of components of multiple star system | 4 |
| separation | 90 arcsec |
| mag difference (of double or brightest multiple) | 6,8 |
| component ID | AD |
| note (category: double and multiple data): | Companions B and C optical. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 19h 40min 5,775sec | DEC: +18° 0' 50'' | ±0,2 arcsec | source: 52 |
| proper motion (J2000) | RA: 0,0005 arcsec/a | DEC: -0,02 arcsec/a | source: 25 | |
| radial velocity | 2 km/s | source: 25 | ||
| galactic coord. (B1950) | longitude: 54,46° | latitude: -2,14° | ||
| GCI unit vector (J2000) | X: 0,402264 | Y: -0,861713 | Z: 0,309248 | |
magnitude:
| visual | 4,37 (observed) | source: 25 |
| photovisual | 4,4 | source: 2 |
| photographic | 5,1 | source: 16 |
spectral information:
| spectral class | G0 | source: 96 | |
| Morgan-Keenan | G1II | source: 25 | |
| B-magnitude | 5,15 ±0,05 | B-V-magnitude | 0,78 |
| U-magnitude | 5,58 ±0,05 | U-B-magnitude | 0,43 |
double/multiple star system information:
| separation between brightest and second brightest component | 30,8 arcsec |
| magnitude difference between brightest and second brightest component | 8,8 |
| position angle | 179 ° |
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 | |
| 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 (J1950) | RA: 19h 37min 51,612sec | DEC: +17° 53' 51,21'' | ±0,015 arcsec |
| position (J2000) | RA: 19h 40min 5,779sec | DEC: +18° 0' 49,69'' | |
| proper motion J1950 (FK4) | RA: 0,0009 arcsec/a | DEC: -0,02 arcsec/a | ±0,002 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,001 arcsec/a | DEC: -0,021 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4,4 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | G0 |
| 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: 27215 |
| Durchmusterung | BD+17 4042 |
| Boss General Catalogue | 27215 |
| Henry Draper Catalogue | 185758 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 19h 40,1min | DEC: +18° 1' |
| proper motion (J2000) | RA: 0,02 arcsec/a | DEC: -0,021 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 | 1910 | 4 | 180° | 33'' | 4,37 | 13,2 | G1III | J 121 |
| 1985 | 179° | 30,8'' | ||||||
| AC | 1910 | 1 | 249° | 35,8'' | 4,37 | 14,9 | - | J 121 |
discoverer information:
| discoverer code | discoverer | reference |
| J 121 | Jonckheere, R. | - |
notes:
| note | Alpha Sge. |