x Ursae Majoris
| catalogues and names | x UMa, ksi UMa, 53 UMa, HR 4374, HD 98230, SAO 62484, WDS 11182+3132B |
| constellation | Ursa Major |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 11h 18min 10,9sec | DEC: +31° 31' 45'' |
| position (J1900) | RA: 11h 12min 50,9sec | DEC: +32° 5' 31'' |
| proper motion (J2000) | RA: -0,432 arcsec/a | DEC: -0,586 arcsec/a |
| radial velocity | -16 km/s note: spectroscopic binaries, single lined spectra note: orbital data avaible |
|
| rotational velocity | 3 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,137 arcsec | |
| note (category: dynamical parallaxes): | 0.120". |
magnitude
| visual magnitude | 4,87 (original HR magnitude) |
spectral / color information
| spectral class | G0V |
| note (category: spectra): | Xi UMa B has low lithium abundance while its companion has high. |
variability information
| variable star identification | 5165 |
| note (category: variability): | Blend of 4374-5. Amp. 0.03V. |
double/multiple star system information
| number of components of multiple star system | 4 |
| separation | 3,1 arcsec |
| mag difference (of double or brightest multiple) | 0,5 |
| component ID | AB |
| note (category: double and multiple data): | Binary with HR 4375, q.v. |
| note (category: spectroscopic binaries): | 3.9805d, K 5.0k/s, V0 -15.9k/s, asini 0.274. Unresolved by speckle interferometry 1982.17. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 11h 18min 10,95sec | DEC: +31° 31' 45,6'' | ±0,76 arcsec | source: 18 |
| proper motion (J2000) | RA: -0,0336 arcsec/a | DEC: -0,586 arcsec/a | source: 25 | |
| radial velocity | -16 km/s | source: 25 | ||
| trigonometric parallax | 0,137 | ±0,014 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 195,09° | latitude: 69,25° | ||
| GCI unit vector (J2000) | X: -0,838223 | Y: 0,154665 | Z: 0,522935 | |
magnitude:
| visual | 4,79 (observed) | source: 25 |
| photovisual | 4,9 | source: 2 |
| photographic | 5,4 | source: 2 |
spectral information:
| spectral class | G0 | source: 29 | |
| Morgan-Keenan | G2V | source: 25 | |
| B-magnitude | 5,38 ±0,005 | B-V-magnitude | 0,59 |
| U-magnitude | 5,42 ±0,009 | U-B-magnitude | 0,04 |
variability information:
| variability type | 273 |
| var. amplitude | 0 |
double/multiple star system information:
| magnitude difference between brightest and second brightest component | 0,5 |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4,32 | G0 | Alula Australis, x Ursae Majoris, 53 UMa, HR 4375, HD 98231, SAO 62484 |
| B | 4,79 | G0 | x Ursae Majoris, 53 UMa, HR 4374, HD 98230, SAO 62484 |
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 | |
| 18 | Hipparcos Input Catalog Version 2 Annex |
| Turon, C., et al., "The Hipparcos Input Catalog, Version 2," Centre de Donnees Stellaires Information Bulletin, Vol. 43, p. 5, 1993 | |
| 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 | |
| 27 | Catalog of Red Magnitudes (CRM) |
| Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 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: 11h 15min 31,162sec | DEC: +31° 48' 38,88'' | ±0,011 arcsec |
| position (J2000) | RA: 11h 18min 10,938sec | DEC: +31° 31' 45,24'' | |
| proper motion J1950 (FK4) | RA: -0,0339 arcsec/a | DEC: -0,591 arcsec/a | ±0,002 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0338 arcsec/a | DEC: -0,586 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 3,9 (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. |
catalogues
| source catalogue | GC, catalogue number: 15537 |
| Durchmusterung | BD+32 2132 |
| Boss General Catalogue | 15537 |
| Henry Draper Catalogue | 98230 The "SAO Catalog" entry refers to two consecutive HD numbers, the lower of which is given. |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 11h 18,2min | DEC: +31° 32' |
| proper motion (J2000) | RA: -0,428 arcsec/a | DEC: -0,592 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 |
| - | 1826 | often | ° | '' | 4,4 | 4,9 | G0V G5V | STF1523 |
| Bb | 1988 | 1 | 104° | 0,1'' | 4,4 | - | - | CHR 178 |
| AC | 1990 | 1 | 314° | 54,3'' | 4,4 | 15 | - | POP |
discoverer information:
| discoverer code | discoverer | reference |
| STF1523 | Struve, F.G.W. | - |
| CHR 178 | - | - |
| POP | Popovic, G. |
notes:
| note | Xi UMa. P = 59.8yr., a = 2.53", motion retrograde. A is known to have an unseen companion, P = 1.83yr. B is a spectroscopic binary. |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 11h 15min 31,2sec | DEC: +31° 48' 39'' |
variability informations:
| variability type | RS | eruptive variable star |
| magnitute at max. brightness | 4,38 | |
| magnitute amplitude | 0,01 | |
| photometric system | visual, photovisual or Johnson's V |
references
| to a study | K.G.Strassmeier, D.S.Hall, L.J.Boyd, R.M.Genet, ApJ Suppl 69,141,1989. |
| to a chart/photograph | no chart is avaible, but the star is contained in the 'Bonner Durchmusterung' |
miscanellous
| ID in the GCVS catalogue | 83/9014 |
| constellation | Ursa Major |
| notes on existence | The star is equivalent to '70083'. |
variability type description
| variability type | description |
| RS | Eruptive variables of the RS Canum Venaticorum type. This type is ascribed to close binary systems with spectra showing Ca II H and K in emission, their components having enhanced chromospheric activity that causes quasi-periodic light variability. The period of variation is close to the orbital one, and the variability amplitude is usually as great as 0.2 mag in V (UX Ari). They are X-ray sources and rotating variables. RS CVn itself is also an eclipsing system. |