y1Draconis
catalogues and names
| catalogues and names | y1Dra, 31 Dra, HR 6637, HD 162004, SAO 8891, BD +72 805, WDS 17419+7209B |
| constellation | Draco |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Some catalogues call HR 6636 Psi1, 6637 Psi2; most, however, call 6636/7 Psi1 and 6725 Psi2. |
position, motion, parallax:
| position (J2000) | RA: 17h 41min 58sec | DEC: +72° 9' 25'' | ||
| position (2001,17) | RA: 17h 41min 57sec | DEC: +72° 9' 23'' | ||
| position (B1900) | RA: 17h 43min 44,6sec | DEC: +72° 12' 22'' | ||
| proper motion (J2000) | RA: 0,03 arcsec/a | DEC: -0,278 arcsec/a | ||
| radial velocity | -10 km/s note: suspected variable radial velocity |
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| rotational velocity | =<25 km/s (uncertain) (variable) | |||
| trigonometric parallax | 0,054 arcsec | |||
| galactic coordinates | longitude: 102,98° | latitude: 31,03° | ||
magnitude
| visual magnitude | 5,79 (V on UBV Johnson system) |
spectral / color information
| spectral class | G0V |
| B-V-magnitude | 0,53 |
| U-B-magnitude | 0,02 |
double/multiple star system information
| number of components of multiple star system | 4 |
| separation | 30,2 arcsec |
| mag difference (of double or brightest multiple) | 1,2 |
| component ID | AB |
| note (category: double and multiple data): | CPM with HR 6636. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 17h 41min 58,143sec | DEC: +72° 9' 24,82'' | ±0,2 arcsec | source: 52 |
| position (2001,17) | RA: 17h 41min 57sec | DEC: +72° 9' 23'' | JD: 2451973,11 | |
| proper motion (J2000) | RA: 0,0079 arcsec/a | DEC: -0,277 arcsec/a | source: 25 | |
| radial velocity | -10 km/s | source: 25 | ||
| trigonometric parallax | 0,054 arcsec | ±0,005 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 102,98° | latitude: 31,03° | ||
magnitude:
| visual | 5,79 (observed) | source: 25 |
| photovisual | 6,1 | source: 2 |
| photographic | 6,5 | source: 16 |
spectral information:
| spectral class | F5 | source: 96 | |
| Morgan-Keenan | G0V | source: 25 | |
| B-magnitude | 6,32 ±0,05 | B-V-magnitude | 0,53 |
| U-magnitude | 6,34 ±0,05 | U-B-magnitude | 0,02 |
double/multiple star system information:
| separation between brightest and second brightest component | 30,2 arcsec |
| magnitude difference between brightest and second brightest component | 1,2 |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4,58 | F5 | Dsiban, y1Draconis, 31 Dra, HR 6636, HD 162003, SAO 8890 |
| B | 5,79 | F5 | y1Draconis, 31 Dra, HR 6637, HD 162004, SAO 8891 |
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 | |
| 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 (B1950) | RA: 17h 42min 50,929sec | DEC: +72° 10' 55,38'' | ±0,017 arcsec |
| position (2001,17) | RA: 17h 41min 56sec | DEC: +72° 9' 36'' | JD: 2451973,11 |
| position (J2000) | RA: 17h 41min 57,951sec | DEC: +72° 9' 24,67'' | |
| proper motion B1950 (FK4) | RA: 0,0041 arcsec/a | DEC: -0,278 arcsec/a | ±0,003 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0065 arcsec/a | DEC: -0,278 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 6,1 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | F5 |
| 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: 24090 |
| Durchmusterung | BD+72 805 |
| Boss General Catalogue | 24090 |
| Henry Draper Catalogue | 162004 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 17h 41,9min | DEC: +72° 9' |
| proper motion (J2000) | RA: 0,025 arcsec/a | DEC: -0,267 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 | 1832 | 56 | 15° | 30,3'' | 4,58 | 5,79 | F5IV F8V | STF2241 |
| AC | 1857 | 7 | 128° | 101,5'' | 4,9 | 11,4 | - | STF2241 |
| 1923 | 120° | 89,7'' | ||||||
| AD | 1905 | 1 | 84° | 100,5'' | 4,9 | 12,9 | - | STF2241 |
| CD | 1908 | 1 | 19° | 67,6'' | 11,4 | 12,9 | - | STF2241 |
discoverer information:
| discoverer code | discoverer | reference |
| STF2241 | Struve, F.G.W. | - |
notes:
| note | Psi (1) Dra. B is BD+72@805. Proper motion of B +017 -279. A premature orbit has been computed. |