g1Delphini
| catalogues and names | g1Del, 12 Del, HR 7947, HD 197963, SAO 106475, WDS 20467+1607B |
| constellation | Delphinus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 20h 46min 38,7sec | DEC: +16° 7' 28'' |
| position (J1900) | RA: 20h 42min 0,3sec | DEC: +15° 45' 49'' |
| proper motion (J2000) | RA: -0,03 arcsec/a | DEC: -0,191 arcsec/a |
| radial velocity | -7 km/s note: suspected variable radial velocity |
|
| rotational velocity | =<25 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,026 arcsec | |
| note (category: dynamical parallaxes): | 0.033". |
magnitude
| visual magnitude | 5,14 (V on UBV Johnson system) |
spectral / color information
| spectral class | F7V |
| B-V-magnitude | 0,49 |
| U-B-magnitude | 0,08 |
double/multiple star system information
| separation | 9,8 arcsec |
| mag difference (of double or brightest multiple) | 1 |
| note (category: double and multiple data): | 3249y, a = 13.813". Binary with HR 7948. |
miscellaneous information
| note (category: group membership): | Wolf 630 group. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 20h 46min 38,837sec | DEC: +16° 7' 26,95'' | ±0,5 arcsec | source: 25 |
| proper motion (J2000) | RA: -0,0022 arcsec/a | DEC: -0,197 arcsec/a | source: 25 | |
| radial velocity | -7 km/s | source: 25 | ||
| trigonometric parallax | 0,026 | ±0,003 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 61,5° | latitude: -16,57° | ||
| GCI unit vector (J2000) | X: 0,638583 | Y: -0,717693 | Z: 0,27772 | |
magnitude:
| visual | 5,14 (observed) | source: 25 |
| photovisual | 5,5 | source: 2 |
| photographic | 6,3 | source: 2 |
spectral information:
| spectral class | F8 | source: 29 | |
| Morgan-Keenan | F7V | source: 25 | |
| B-magnitude | 5,63 ±0,05 | B-V-magnitude | 0,49 |
| U-magnitude | 5,71 ±0,05 | U-B-magnitude | 0,08 |
double/multiple star system information:
| separation between brightest and second brightest component | 9,6 arcsec |
| magnitude difference between brightest and second brightest component | 0,87 |
| position angle | 267 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4,27 | G5 | g2Delphini, 12 Del, HR 7948, HD 197964, SAO 106476 |
| B | 5,14 | F8 | g1Delphini, 12 Del, HR 7947, HD 197963, SAO 106475 |
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 | |
| 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 | |
| 29 | SAOJ2000 |
| SAO on FK5 at J2000, 1989 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (J1950) | RA: 20h 44min 19,473sec | DEC: +15° 56' 34,71'' | ±0,018 arcsec |
| position (J2000) | RA: 20h 46min 38,737sec | DEC: +16° 7' 27,59'' | |
| proper motion J1950 (FK4) | RA: -0,0022 arcsec/a | DEC: -0,188 arcsec/a | ±0,006 arcsec/a in RA ±0,007 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0021 arcsec/a | DEC: -0,191 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5,2 (accuracy: 1 decimal) |
| source of visual magnitude data | Taken from AGK1. |
spectral information:
| spectral class | F8 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | Yale Transactions 18, catalogue number: 8382 |
| Durchmusterung | BD+15 4255B |
| Boss General Catalogue | 28965 |
| Henry Draper Catalogue | 197963 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 20h 46,7min | DEC: +16° 7' |
| proper motion (J2000) | RA: -0,032 arcsec/a | DEC: -0,197 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 |
| - | 1823 | often | 274° | 11,9'' | 4,27 | 5,14 | K1IV F7V | STF2727 |
| 1988 | 267° | 9,6'' |
discoverer information:
| discoverer code | discoverer | reference |
| STF2727 | Struve, F.G.W. | - |
notes:
| note | Gamma Del. A premature orbit has been computed. |