j Draconis
catalogues and names
| catalogues and names | j Dra, phi Dra, 43 Dra, HR 6920, HD 170000, SAO 9084, BD +71 889, WDS 18208+7120A |
| constellation | Draco |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 18h 20min 45.5sec | DEC: +71° 20' 16'' | ||
| position (2000.72) | RA: 18h 20min 45sec | DEC: +71° 20' 17'' | ||
| position (B1900) | RA: 18h 22min 11.4sec | DEC: +71° 17' 5'' | ||
| proper motion (J2000) | RA: -0.004 arcsec/a | DEC: 0.04 arcsec/a | ||
| radial velocity | -16 km/s note: spectroscopic binaries, single lined spectra note: orbital data avaible |
|||
| rotational velocity | 88 km/s (uncertain) (variable) | |||
| trigonometric parallax | 0.012 arcsec | |||
| galactic coordinates | longitude: 101.88° | latitude: 28.04° | ||
| note (category: dynamical parallaxes): | 0.003". |
magnitude
| visual magnitude | 4.22 (V on UBV Johnson system) |
spectral / color information
| spectral class | A0pSi: |
| B-V-magnitude | -0.1 |
| U-B-magnitude | -0.33 |
| R-I-magnitude |
| note (category: spectra): | Also classified B8Vp. |
variability information
| variable star identification | Phi Dra |
| note (category: variability): | Alpha CV, amp. 0.04V, 1.71646d. Same rotation period. |
double/multiple star system information
| number of components of multiple star system | 3 |
| separation | 0.2 arcsec |
| mag difference (of double or brightest multiple) | 1.7 |
| component ID | AB |
| note (category: double and multiple data): | 4.4, 6.1v, 271.7y, a = 0.392". |
| note (category: spectroscopic binaries): | 26.768d, K 26.6k/s, V0 -20.8k/s, asini 9.02. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 18h 20min 45.43sec | DEC: +71° 20' 16.15'' | ±0.35 arcsec | source: 17 |
| position (2000.72) | RA: 18h 20min 44sec | DEC: +71° 20' 17'' | JD: 2451809.24 | |
| proper motion (J2000) | RA: -0.001 arcsec/a | DEC: 0.036 arcsec/a | source: 25 | |
| radial velocity | -16 km/s | source: 25 | ||
| trigonometric parallax | 0.012 arcsec | ±0.001 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 101.88° | latitude: 28.04° | ||
magnitude:
| visual | 4.22 (observed) | source: 25 |
| photovisual | 4.2 | source: 2 |
| photographic | 4.2 | source: 16 |
spectral information:
| spectral class | A0 | source: 96 | |
| Morgan-Keenan | A0pSi: | source: 25 | |
| B-magnitude | 4.12 ±0.05 | B-V-magnitude | -0.1 |
| U-magnitude | 3.79 ±0.05 | U-B-magnitude | -0.33 |
variability information:
| variability type | 160 |
| var. amplitude | 0.04 |
| var. period | 1.72 |
| var. epoch | 2442229 30. June 1974, 12:00:00 UT |
| next max light | 2451809.4 21. September 2000, 21:36:00 UT |
double/multiple star system information:
| separation between brightest and second brightest component | 0.5 arcsec |
| magnitude difference between brightest and second brightest component | 1.5 |
| position angle | 271 ° |
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 | |
| 30 | GCVS, 4th edition |
| Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88 | |
| 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: 18h 21min 28.505sec | DEC: +71° 18' 42.23'' | ±0.009 arcsec |
| position (2000.72) | RA: 18h 20min 45sec | DEC: +71° 20' 16'' | JD: 2451809.24 |
| position (J2000) | RA: 18h 20min 45.453sec | DEC: +71° 20' 16.44'' | |
| proper motion B1950 (FK4) | RA: -0.002 arcsec/a | DEC: 0.041 arcsec/a | ±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.0009 arcsec/a | DEC: 0.04 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4.2 (accuracy: 2 decimals) |
| source of visual magnitude data | Combined magnitude of component stars. |
spectral information:
| spectral class | A0p |
| source of spectral data | Taken from the HD with M stars reclassified by Miss Cannon. |
remarks for duplicity and variability
| Double star - see source catalog for source |
catalogues
| source catalogue | FK3, catalogue number: 693 |
| Durchmusterung | BD+71 889 |
| Boss General Catalogue | 25114 |
| Henry Draper Catalogue | 170000 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 18h 20.8min | DEC: +71° 20' |
| proper motion (J2000) | RA: -0.005 arcsec/a | DEC: 0.036 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 | 1843 | 61 | 64° | 0.6'' | 4.5 | 6 | A0pSi: | STT 353 |
| 1993 | 271° | 0.5'' | ||||||
| AB-C | 1912 | 2 | 115° | 70.8'' | 4.4 | 12.7 | - | STT 353 |
| 1962 | 116° | 71.8'' |
discoverer information:
| discoverer code | discoverer | reference |
| STT 353 | Struve, O. | - |
notes:
| note | Phi Dra. A premature orbit has been computed. A is an Alpha CVn-type variable and spectroscopic binary. |
data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
| position (B1900) | RA: 18h 22.2min | DEC: +71° 17' |
magnitudes, spectral classes, orbital elements:
| author: | D. Olevic |
| date of observation: | 1968 |
| magnitude of component A: | 4.4 |
| magnitude of component B: | 4.4 |
| spectral class component B: | A0p |
| spectral class component B: | A0p |
| period [y]: | 271.7 |
| semi-major axis [arcsec]: | 0.392 |
| inclination [deg]: | 118.96 |
| node [deg]: | 72.25 |
| eccentricity: | 0.44 |
| time of periastron passage: | 1720.75 |
| dates of ephemeris: | 1974-1980 |
| grade: | indeterminate |
| reference: | Bull. Obs. Beograd No. 126, 49; 1975. |
| notes | Star A is a single-lined spectroscopic binary, probable P = 27 d,and also an Alpha CVn type variable. |