The pre-main sequence star HD 34282: A very short period delta   Scuti-type pulsator
  HD 34282 has been found to pulsate during a systematic search for short-term photometric variability in Herbig Ae/Be stars with the goal of determining the position and size of the pre-main sequence instability strip. Simultaneous Stromgren photometry is used in the frequency analysis, yielding two frequencies with values of nu1=79.5 and nu2=71.3 c/d. The light curve with the largest amplitude is that of the u band. This behaviour, which is not common for delta Scuti stars, is explained as pulsation in a high radial order in stars near the blue edge of the instability strip. The main period, with a value of 18.12 min, represents the shortest period observed so far for a delta Scuti-type pulsator. A seismic modelling, including instability predictions and rotation effects, has been attempted. It is found that both main sequence and pre-main sequence models predict modes in the range of 56 to 82 c/d (between 648 and 949 microHz), corresponding to oscillations of radial order n from 6 to 8. The highest of the observed frequencies only becomes unstable for models of low metallicity, in agreement with results from spectroscopic measurements. 
P. J. Amado, A. Moya, J. C. Suarez, S. Martin-Ruiz, R. Garrido, E.   Rodriguez, C. Catala, M. J. Goupil