- Sternwarte der Universität Bonn, Germany
- Kitt Peak National Observatory, Tucson, Arizona, USA
A new set of photoelectric B and V observations of W Ursae Majoris obtained during a period of one week in 1968 is presented. From the measurements it can be concluded that in general the light curve in both colors is free from complications. In particular, no systematic brightness differences between consecutive periods can be found. The observations made during total eclipse in two different periods yield flat minima fitting almost perfectly together, the mean error of the single measurement beeing of the order of 0.m003. The duration of the phase of totality is estimated to 0.036P=17.3 m thus confirming the value given by Cester and Gridelli. From a plot of the square deviations of the single observations (?I/I)2 from the mean intensity curve vs phase it can be shown that the scattering decreases strongly during primary eclipse thus indicating that the source producing these fluctuations is essentially confined to the space between the two components. A comparison with earlier photoelectric observations also supports the assumption that the variational behavior of the light curve is caused by a gaseous cloud between the two components rather than by an envelope surrounding the whole system.
- 1 - natural sciences ; 2 - physics & astronomy ; 3 - astronomy & astrophysics
- 1 - sciences appliquees, technologies et medecines ; 2 - sciences biologiques et medicales ; 3 - sciences biologiques fondamentales et appliquees. psychologie
- 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Space and Planetary Science
- 1 - Physical Sciences ; 2 - Physics and Astronomy ; 3 - Astronomy and Astrophysics