z Sagitta
| catalogues and names | z Sge, 8 Sge, HR 7546, HD 187362, SAO 105298, WDS 19490+1909A |
| constellation | Sagitta |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 19h 48min 58,7sec | DEC: +19° 8' 32'' |
| position (J1900) | RA: 19h 44min 32,3sec | DEC: +18° 53' 28'' |
| proper motion (J2000) | RA: 0,021 arcsec/a | DEC: 0,03 arcsec/a |
| radial velocity | -14 km/s note: variable radial velocity |
|
| rotational velocity | 225 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,01 arcsec | |
| note (category: radial and/or rotational velocities): | ADS 12973A, suspected SB. |
| note (category: dynamical parallaxes): | 0.010". |
magnitude
| visual magnitude | 5 (V on UBV Johnson system) |
spectral / color information
| spectral class | A3V |
| B-V-magnitude | 0,1 |
| U-B-magnitude | 0,05 |
| R-I-magnitude | 0,06 |
double/multiple star system information
| number of components of multiple star system | 4 |
| separation | 0,2 arcsec |
| mag difference (of double or brightest multiple) | 0,5 |
| component ID | AB |
| note (category: double and multiple data): | AB 5.5 A1V, 6.2 A3V, 22.8y, a = 0.146". Masses 4.0, 2.0 solar. C, 8.7v at 8" physical. Speckle interferometry 1985.5 gives sep. 0.180". |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 19h 48min 58,658sec | DEC: +19° 8' 31,24'' | ±0,35 arcsec | source: 17 |
| proper motion (J2000) | RA: 0,0013 arcsec/a | DEC: 0,025 arcsec/a | source: 25 | |
| radial velocity | -14 km/s | source: 25 | ||
| trigonometric parallax | 0,01 | ±0,001 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 56,49° | latitude: -3,4° | ||
| GCI unit vector (J2000) | X: 0,432475 | Y: -0,839905 | Z: 0,327911 | |
magnitude:
| visual | 5 (observed) | source: 25 |
| photovisual | 5 | source: 2 |
| photographic | 5 | source: 16 |
spectral information:
| spectral class | A2 | source: 96 | |
| Morgan-Keenan | A3V | source: 25 | |
| B-magnitude | 5,1 ±0,05 | B-V-magnitude | 0,1 |
| U-magnitude | 5,15 ±0,05 | U-B-magnitude | 0,05 |
double/multiple star system information:
| magnitude difference between brightest and second brightest component | 1 |
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 | |
| 17 | ACRS |
| Corbin, T.E., and S.E. Urban, Astrographic Catalog Reference Stars, United States Naval Observatory, 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 (J1950) | RA: 19h 46min 45,415sec | DEC: +19° 0' 55,54'' | ±0,014 arcsec |
| position (J2000) | RA: 19h 48min 58,674sec | DEC: +19° 8' 31,52'' | |
| proper motion J1950 (FK4) | RA: 0,0014 arcsec/a | DEC: 0,031 arcsec/a | ±0,003 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0015 arcsec/a | DEC: 0,03 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | A2 |
| 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: 27431 |
| Durchmusterung | BD+18 4254 |
| Boss General Catalogue | 27431 |
| Henry Draper Catalogue | 187362 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 19h 49min | DEC: +19° 9' |
| proper motion (J2000) | RA: 0,018 arcsec/a | DEC: 0,025 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 | 1878 | often | ° | '' | 5,4 | 6,4 | A1V | AGC 11 |
| AB-C | 1822 | 84 | 311° | 8,6'' | 5,04 | 9,03 | - | STF2585 |
| 1987 | - | 8,4'' | ||||||
| AB-D | 1921 | 3 | 248° | 74,7'' | 5,04 | 11 | - | STF2585 |
| 1971 | 247° | 76'' |
discoverer information:
| discoverer code | discoverer | reference |
| AGC 11 | - | - |
| STF2585 | Struve, F.G.W. | - |
notes:
| note | Zeta Sge. P = 23.22yr., a = 0.136", motion retrograde. A is a suspected spectroscopic binary. AB-C: C is physical. |