ET Ursae Majoris
catalogues and names
| catalogues and names | ET UMa, HR 4072, HD 89822, SAO 15163, BD +66 664, FK5: 387 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 10h 24min 7.9sec | DEC: +65° 33' 59'' | ||
| position (2000.72) | RA: 10h 24min 11sec | DEC: +65° 33' 46'' | ||
| position (B1900) | RA: 10h 16min 55.5sec | DEC: +66° 4' 20'' | ||
| proper motion (J2000) | RA: -0.008 arcsec/a | DEC: -0.022 arcsec/a | ||
| radial velocity | 0 km/s note: spectroscopic binaries, double lined spectra note: orbital data avaible |
|||
| rotational velocity | 15 km/s (uncertain) (variable) | |||
| trigonometric parallax | 0.043 arcsec | |||
| galactic coordinates | longitude: 143.54° | latitude: 45.22° | ||
magnitude
| visual magnitude | 4.97 (V on UBV Johnson system) |
spectral / color information
| spectral class | A0pSiSr:Hg: |
| B-V-magnitude | -0.06 |
| U-B-magnitude | -0.13 |
| R-I-magnitude |
| note (category: spectra): | HgMn star; SrII 4077; Pt II. |
variability information
| variable star identification | 4839 |
| note (category: variability): | Alpha CV?, 4.91 - 4.99V. |
double/multiple star system information
| note (category: spectroscopic binaries): | 11.5791d, K 38.9k/s, V0 -2.6k/s, msin3i 0.754, asini 5.98. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 10h 24min 7.852sec | DEC: +65° 33' 59.01'' | ±0.06 arcsec | source: 15 |
| position (2000.72) | RA: 10h 24min 11sec | DEC: +65° 33' 46'' | JD: 2451809.25 | |
| proper motion (J2000) | RA: -0.0013 arcsec/a | DEC: -0.022 arcsec/a | source: 25 | |
| radial velocity | 0 km/s | source: 25 | ||
| trigonometric parallax | 0.043 arcsec | ±0.004 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 143.54° | latitude: 45.22° | ||
magnitude:
| visual | 4.97 (observed) | source: 25 |
| photovisual | 4.9 | source: 2 |
spectral information:
| spectral class | A0 | source: 96 | |
| Morgan-Keenan | A0pSiSr:Hg: | source: 25 | |
| B-magnitude | 4.91 ±0.05 | B-V-magnitude | -0.06 |
| U-magnitude | 4.78 ±0.05 | U-B-magnitude | -0.13 |
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 | |
| 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 (B1950) | RA: 10h 20min 33.038sec | DEC: +65° 49' 12.47'' | ±0.005 arcsec |
| position (2000.72) | RA: 10h 24min 11sec | DEC: +65° 33' 46'' | JD: 2451809.25 |
| position (J2000) | RA: 10h 24min 7.85sec | DEC: +65° 33' 59.01'' | |
| proper motion B1950 (FK4) | RA: -0.0015 arcsec/a | DEC: -0.025 arcsec/a | ±0.001 arcsec/a in RA ±0.001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.0013 arcsec/a | DEC: -0.022 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4.9 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | A0 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 387 |
| Durchmusterung | BD+66 664 |
| Boss General Catalogue | 14260 |
| Henry Draper Catalogue | 89822 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (equinox 1950.0) | RA: 10h 20min 33sec | DEC: +65° 49' 12'' |
variability informations:
| variability type | ACV | rotating variable star |
| magnitute at max. brightness | 4.91 | |
| magnitute amplitude | 0.05 | |
| photometric system |
references
| to a study | F.A.Catalono, F.Leone, AsAp 244, No.2, 327, 1991. |
| to a chart/photograph | no chart is avaible, but the star is contained in the 'Bonner Durchmusterung' |
miscanellous
| ID in the GCVS catalogue | 83/163 |
| constellation | Ursa Major |
| notes on existence | The star is equivalent to '72136'. |
variability type description
| variability type | description |
| ACV | Alpha2 Canum Venaticorum variables. These are main-sequence stars with spectral types B8p-A7p and displaying strong magnetic fields. Spectra show abnormally strong lines of Si, Sr, Cr, and rare earths whose intensities vary with rotation. They exhibit magnetic field and brightness changes (periods of 0.5-160 days or more). The amplitudes of the brightness changes are usually withine 0.01-0.1 mag in V. ACVO Rapidly oscillating Alpha2 CVn variables. These are nonradially pulsating, rotating magnetic variables of Ap spectral type (DO Eri). Pulsation periods are in the range of 6-12 mmag (0.004-0.01 days), while amplitudes of light variation caused by the pulsation are about 0.01 mag in V. The pulsational variations are superposed on those caused by rotation. |