z2Cancri
| catalogues and names | z2Cnc, 16 Cnc, HR 3210, HD 68255, SAO 97646, WDS 08122+1739B |
| constellation | Cancer |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 8h 12min 13,3sec | DEC: +17° 38' 52'' |
| position (J1900) | RA: 8h 6min 29sec | DEC: +17° 56' 55'' |
| proper motion (J2000) | RA: 0,097 arcsec/a | DEC: -0,109 arcsec/a |
| radial velocity | -11 km/s note: variable radial velocity |
|
| trigonometric parallax | 0,039 arcsec | |
| note (category: dynamical parallaxes): | 0.031". |
magnitude
| visual magnitude | 6,2 (V on UBV Johnson system) |
spectral / color information
| spectral class | G5V |
| B-V-magnitude | 0,6 |
| U-B-magnitude | 0,13 |
double/multiple star system information
| number of components of multiple star system | 5 |
| separation | 5,9 arcsec |
| mag difference (of double or brightest multiple) | 1,2 |
| component ID | ABxC |
| note (category: double and multiple data): | See HR 3208. C* 6.20 G5V, 17.5y, a = 0.191". Astrometric companion also found by occultation, 9.0v. Cc resolved by speckle interferometry. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 8h 12min 12,778sec | DEC: +17° 38' 51,5'' | ±0,35 arcsec | source: 17 |
| proper motion (J2000) | RA: 0,0056 arcsec/a | DEC: -0,142 arcsec/a | source: 25 | |
| radial velocity | -6 km/s | source: 25 | ||
| trigonometric parallax | 0,039 | ±0,004 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 205,31° | latitude: 25,53° | ||
| GCI unit vector (J2000) | X: -0,51975 | Y: 0,798719 | Z: 0,303162 | |
magnitude:
| visual | 6,02 (observed) | source: 25 |
| photovisual | 6,3 | source: 2 |
| photographic | 6,8 | source: 2 |
spectral information:
| Morgan-Keenan | F9V | source: 25 | |
| B-magnitude | 6,56 ±0,05 | B-V-magnitude | 0,54 |
| U-magnitude | 6,62 ±0,05 | U-B-magnitude | 0,06 |
double/multiple star system information:
| magnitude difference between brightest and second brightest component | 0,4 |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 5,63 | G0 | Tegmine, z1Cancri, 16 Cnc, HR 3208, HD 68257, SAO 97645 |
| B | 6,02 | - | z1Cancri, 16 Cnc, HR 3209, HD 68256, SAO 97645 |
| C | 6,2 | - | z2Cancri, 16 Cnc, HR 3210, HD 68255, SAO 97646 |
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 | |
| 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 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (J1950) | RA: 8h 9min 21,213sec | DEC: +17° 47' 58,38'' | ±0,032 arcsec |
| position (J2000) | RA: 8h 12min 13,263sec | DEC: +17° 38' 51,63'' | |
| proper motion J1950 (FK4) | RA: 0,0069 arcsec/a | DEC: -0,112 arcsec/a | ±0,005 arcsec/a in RA ±0,004 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0068 arcsec/a | DEC: -0,108 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 6 (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: 11142 |
| Durchmusterung | BD+18 1867C |
| Boss General Catalogue | 11142 |
| Henry Draper Catalogue | 68255 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 8h 12,2min | DEC: +17° 39' |
| proper motion (J2000) | RA: 0,081 arcsec/a | DEC: -0,142 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 | 1826 | often | ° | '' | 5,6 | 6 | F8V | STF1196 |
| AB-C | 1821 | often | 160° | 5,3'' | 5,05 | 6,2 | G0V | STF1196 |
| 1987 | 82° | 5,7'' | ||||||
| AB-D | 1887 | 5 | 108° | 293,4'' | - | 9,7 | - | STF1196 |
| 1984 | - | 283,2'' | ||||||
| AC | 1821 | often | 160° | 5,7'' | 5,6 | 6,3 | - | STF1196 |
| 1992 | 80° | 5,3'' | ||||||
| AB-E | 1887 | 1 | 27° | 9,1'' | - | - | - | ENH 1 |
| AB-F | 1887 | 1 | 47° | 10,5'' | - | - | - | ENH 1 |
| AB-G | 1887 | 1 | 331° | 10,7'' | - | - | - | ENH 1 |
| BC | 1840 | often | 155° | 5,6'' | 6 | 6,3 | - | STF1196 |
| 1965 | 79° | - | ||||||
| CD | 1913 | 3 | 108° | 283,6'' | 6,3 | 10,5 | - | STF1196 |
| 1922 | - | 281'' |
discoverer information:
| discoverer code | discoverer | reference |
| STF1196 | Struve, F.G.W. | - |
| ENH 1 | Engelhardt, von | (Astron. Nachr. 117, 1; 1887.) |
notes:
| note | Zeta Cnc. P = 59.7yr., a = 0.88", motion retrograde. AB-C: A premature orbit has been computed. An unseen companion of C with P = 17.2yr. is known. AB-D: D is BD+18@1870. |
data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
| position (J1900) | RA: 8h 6,5min | DEC: +17° 57' |
magnitudes, spectral classes, orbital elements:
| author: | C. Gasteyer | C. Gasteyer | C. Gasteyer |
| date of observation: | 1951 | 1953 | 1953 |
| magnitude of component A: | 5,63 | 5,05 | 6,2 |
| magnitude of component B: | 5,63 | 5,05 | 6,2 |
| spectral class component B: | F8V | G0V | |
| spectral class component B: | F8V | G0V | |
| period [y]: | 59,7 | 1150 | 17,5 |
| semi-major axis [arcsec]: | 0,884 | 7,96 | 0,191 |
| inclination [deg]: | 172 | 144,6 | 144 |
| node [deg]: | 58 | 256,7 (ascending) | 251 (ascending) |
| equinox of node: | 1900 | 1900 | 1900 |
| eccentricity: | 0,32 | 0,26 | 0,11 |
| time of periastron passage: | 1930 | 1960 | 1944,4 |
| dates of ephemeris: | 1950-1972 | 1950-1972 | |
| grade: | definitive | indeterminate | |
| reference: | Astron. J. 59, 243; 1954. | Ibid. | Ibid. |
| other name(s) | STF 1196 Cc-P |