Abstract:
The rapidly oscillating Ap (roAp) stars are cool, magnetic, chemically peculiar stars which in non-radial p-modes in the period range 4-16 min and have Johnson B amplitudes less than 8 mmag. “The Naini Tal – Cape survey” to search for and study new roAp stars in the northern hemisphere was initiated in 1998 in collaboration between ISAC & UPSO from India and SAAO & UCT from South Afric. HD 12098 is the first roAp star discovered in this survey and also the first far northern hemisphere roAp star. During the initial observations the star showed modulation in the pulsations. The multi-periodicity may be either due ti the excitation of different modes or due to the rotation of the star. In order to resolve these frequencies HD12098 was observed extensively in October 2000. the preliminary results of these observations are presented here.