A search for pulsating pre-main sequence ( PMS ) stars was performed in the young open cluster NGC 6383 using CCD time series photometry in Johnson B & V filters .
With an age of only \sim 1.7 million years all cluster members later than spectral type A0 have not reached the ZAMS yet , hence being ideal candidates for investigating PMS pulsation among A and F type stars .
In total 286 stars have been analyzed using classical Fourier techniques .
From about a dozen of stars within the boundaries of the classical instability strip , two stars were found to pulsate : NGC 6383 # 170 , with five frequencies simultaneously , and NGC 6383 # 198 , with a single frequency .
In addition , NGC 6383 # 152 is a suspected PMS variable star , but our data remain inconclusive .
Linear , non-adiabatic models assuming PMS evolutionary phase and purely radial pulsation were calculated for the two new PMS pulsators .
NGC 6383 # 170 appears to pulsate radially in third and fifth overtones , while the other three frequencies seem to be of non-radial nature .
NGC 6383 # 198 pulsates monoperiodically , most probably in the third radial overtone . Magnitudes and B - V colours were available in the literature for only one third of all stars and we used them for calibrating the remaining .