TIME-RESOLVED SPECTROSCOPY OF THE POST-AGB STAR HD-56126

We have investigated the report of Tamura and Takeuti that the H alpha line of the F-type post-AGB star HD56126 is variable on time-scales o f minutes. To this end, HD 56126 was observed on two occasions with th e William Herschel Telescope. 17 and 30 spectra (first and second runs , respectively) were taken within time-spans of 1.5 h in order to dete ct any short-term variations. We find that the H alpha line profile ch anged strongly over the two-month interval, but no evidence is found f or shortterm variability. The variability Tamura and Takeuti claim to find is probably due to the low signal-to-noise ratio in their spectra .