As the observing runs are too short in 1987 and 1992 to separate the first two periods ( and have a beat period of about 18 days), we find in the period analysis a mixture - weighted by their respective real amplitudes - of both periods. For example, the PDM analysis (Stellingwerf, 1978) on the 1992 b filter data shows, in the 0.15 - 0.21 d range, periods of 0.1702 and 0.1703 day using respectively the 150 cm telescope data, and all data (i.e. including the 84 cm telescope data as well). As we will see later, the conventional periods and weighted by their real amplitudes give a 0.1703 d resulting "mixture". So on our data sample, we have no direct access to an independent determination of (0.1692d) and (0.1708d). However, we easily detect on our data the third period (its beat period with either or is under 3 days) at 0.1814 and 0.1818 d (using respectively the PDM analysis method (Stellingwerf, 1978) for the 150 cm telescope, and for the whole data. Breger's "Period" program (1990) finds 0.1815 d).
© European Southern Observatory (ESO) 1997
Online publication: June 30, 1998