Speaker
Dr
Santosh Joshi
(ARIES, Nainital)
Description
The Nainital-Cape Survey is a dedicated survey programme initiated in 1999 in the coordination of the astronomers from ARIES Nainital and ISRO Bangalore with aims to search for new roAp stars and pulsating Am stars in the northern and southern hemisphere, and perform asteroseismic studies to understand their internal structure and evolution. The candidate stars were selected on the basis of having Strömgren photometric indices similar to those of known pulsating chemically peculiar (CP) stars, and the survey was conducted using high-speed photometry. Over the last 17 years a total of 337 candidate pulsating CP stars were observed for the Nainital-Cape survey, making it one of the longest ground-based surveys for pulsation in CP stars in terms of time span and sample size. Under this survey, we discovered the rapid pulsation in an Ap star HD12098 while Delta Scuti pulsations were detected in seven Am stars. As a part of establishing the detection limits in the Nainital-Cape survey, we investigated the scintillation noise level at the two observing sites used in this survey, Sutherland and Nainital, by comparing the combined frequency spectra of stars observed from each location. Our analysis shows that both the sites permit the detection of variations of the order of 0.6 milli-magnitude (mmag) in the frequency range 1-4 mHz. Sutherland is on average marginally better. In this talk, I shall present the high-lights of the survey project.
Primary author
Dr
Santosh Joshi
(ARIES, Nainital)
