Long-term photometry of variables at ESO. I - The first data catalogue (1982-1986) This paper presents the catalog of photometric data in the Stromgrensystem obtained during the first four years (October 1982 - September1986) of the Long-Term Photometry of Variables (LTPV) program at ESO.The data are available in computer-readable form.
The frequency of Ap-stars with long rotation periods Light variability was observed over time intervals of months to years inthe stars HD 55540, HD 71066, HD 94660, and HD 187474. The significanceof these results is discussed in terms of the frequency of chemicallypeculiar CP2 stars showing (light) variability with periods longer thanone month. This frequency, relative to the whole CP2 population, mustlie somewhere between 4 and 16 percent. Observations, properlydistributed in time, of a small subgroup of CP2 stars will be sufficientto obtain an accurate ratio of the number of LP-CP2 stars to the totalnumber of CP2 stars. These observations, when continued until theperiodicity is detected, could contribute also to the discussion whetherthese long periods should be identified with the rotation period.