SIMBAD references

Intermediate-mass pre-main sequence (PMS) stars cross the instability region on their way to the main sequence and can become pulsationally unstable. The δScuti-like PMS pulsators populate the same area in the Hertzsprung-Russell (HR) diagram as the classical δScuti stars. But the interiors of PMS stars differ from those of their more evolved (post-)main sequence counterparts resulting in different pulsation frequency spectra. Asteroseismology of PMS p-mode pulsators has only recently become possible. The latest investigation focused on the analysis of MOST space photometry of the Herbig Ae star HD 142666 finding 12 pulsational frequencies lying on top of larger irregular variability caused by a circumstellar disk.