4. Optical variability
In Fig. 2 we show the R and I light curves obtained in the first 3 nights, together with those of stars #2 and #3. The latter two do not show any sign of variability, with upper limits to random peak-to-peak variability of mag and mag for star 3, and mag and mag for star 2. V592 Her on the other hand, shows 98.9% significant variability in R with a standard deviation of mag ( upper limit to random peak-to-peak variability of mag). There is no sign of any systematic variability such as an orbital modulation, and the variability in R looks more like random flickering. Because V592 Her is much fainter in I we can only put a upper limit of mag.
Howell et al. (1991) report much larger-amplitude flickering ( mag in wide R) from Duerbeck's star #1 (assuming that their identification refers to the publeshed coordinates).
© European Southern Observatory (ESO) 1999
Online publication: February 23, 1999