Alula Borealis
| catalogues and names | Alula Borealis, n UMa, NSV 18715, 54 UMa, HR 4377, HD 98262, SAO 62486, FK5: 425, WDS 11185+3306 |
| constellation | Ursa Major |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Alula Borealis. |
position, motion, parallax:
| position (J2000) | RA: 11h 18min 28,7sec | DEC: +33° 5' 39'' |
| position (J1900) | RA: 11h 13min 4,7sec | DEC: +33° 38' 24'' |
| proper motion (J2000) | RA: -0,026 arcsec/a | DEC: 0,028 arcsec/a |
| radial velocity | -9 km/s note: spectroscopic binaries |
|
| rotational velocity | <19 km/s | |
| trigonometric parallax | 0,02 arcsec | |
| note (category: dynamical parallaxes): | 0.005". |
magnitude
| visual magnitude | 3,48 (V on UBV Johnson system) |
spectral / color information
| spectral class | K3-IIIBa0.3 |
| B-V-magnitude | 1,4 |
| U-B-magnitude | 1,55 |
| R-I-magnitude | 0,7 |
double/multiple star system information
| separation | 7,2 arcsec |
| mag difference (of double or brightest multiple) | 6 |
| note (category: double and multiple data): | CPM. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 11h 18min 28,738sec | DEC: +33° 5' 39,44'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: -0,0021 arcsec/a | DEC: 0,028 arcsec/a | source: 25 | |
| radial velocity | -9 km/s | source: 25 | ||
| trigonometric parallax | 0,02 | ±0,002 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 190,74° | latitude: 69,08° | ||
| GCI unit vector (J2000) | X: -0,824062 | Y: 0,15095 | Z: 0,546018 | |
magnitude:
| visual | 3,48 (observed) | source: 25 |
| photovisual | 3,7 | source: 2 |
spectral information:
| spectral class | K0 | source: 96 | |
| Morgan-Keenan | K3-III | source: 25 | |
| B-magnitude | 4,88 ±0,05 | B-V-magnitude | 1,4 |
| U-magnitude | 6,43 ±0,05 | U-B-magnitude | 1,55 |
double/multiple star system information:
| separation between brightest and second brightest component | 7,3 arcsec |
| magnitude difference between brightest and second brightest component | 6,6 |
| position angle | 147 ° |
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 | |
| 15 | FK5, FK5 Extension and FK5 Supplement |
| Fricke, W., H. Schwan and T. Lederle, "Fifth Fundamental Catalogue (FK5), Part I. The Basic Fundamental Stars," Veroff. Astronomisches Recheninstitut, No. 32, Heidelberg, Germany, 1988, and Fricke, W., H. Schwan, and T.E. Corbin, "Fifth Fundamental Catalogue (FK5), Part II. The FK5 Extension," Veröff. Astronomisches Recheninstitut, No. 33, Heidelberg, Germany, 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: 11h 15min 46,947sec | DEC: +33° 22' 2,56'' | ±0,004 arcsec |
| position (J2000) | RA: 11h 18min 28,735sec | DEC: +33° 5' 39,4'' | |
| proper motion J1950 (FK4) | RA: -0,0022 arcsec/a | DEC: 0,023 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0021 arcsec/a | DEC: 0,028 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 3,7 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | K0 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 425 |
| Durchmusterung | BD+33 2098 |
| Boss General Catalogue | 15547 |
| Henry Draper Catalogue | 98262 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 11h 18,5min | DEC: +33° 6' |
| proper motion (J2000) | RA: -0,026 arcsec/a | DEC: 0,028 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 |
| - | 1830 | 30 | 147° | 7,1'' | 3,48 | 10,1 | K3IIIBaO | STF1524 |
| 1973 | - | 7,3'' |
discoverer information:
| discoverer code | discoverer | reference |
| STF1524 | Struve, F.G.W. | - |
notes:
| note | Nu UMa. |