The Nainital-Cape Survey-III : A Search for Pulsational Variability in Chemically Peculiar Stars

Abstract

The Nainital-Cape survey is a dedicated research programme to search and study pulsational variability in chemically peculiar stars in the Northern Hemisphere. The aim of the survey is to search such chemically peculiar stars which are pulsationally unstable. The observations of the sample stars were carried out in high-speed photometric mode using a three-channel fast photometer attached to the 1.04-m Sampurnanand telescope at ARIES. The new photometric observations confirmed that the pulsational period of star HD25515 is 2.78-hrs. The repeated time-series observations of HD113878 and HD118660 revealed that previously known frequencies are indeed present in the new data sets. We have estimated the distances, absolute magnitudes, effective temperatures and luminosities of these stars. Their positions in the H-R diagram indicate that HD25515 and HD118660 lie near the main-sequence while HD113878 is an evolved star. We also present a catalogue of 61 stars classified as null results, along with the corresponding 87 frequency spectra taken over the time scale 2002-2008. A statistical analysis of these null results shows, by comparison with past data, that the power of the noise in the light curves has slightly increased during the last few years.

24 pages, 12 figures, accepted for publication in Astronomy and Astrophysics

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Cited by in corpus (14)

• SuperWASP observations of pulsating Am stars
• The Nainital-Cape Survey-III : A Search for Pulsational Variability in Chemically Peculiar Stars
• The Nainital-Cape Survey-IV
• The magnetic field topology and chemical abundance distributions of the Ap star HD 32633
• Time-resolved photometric and spectroscopic analysis of a luminous Ap star HD103498
• A search for rapid pulsations among 9 luminous Ap stars
• A spectroscopic analysis of the chemically peculiar star HD207561
• Asteroseismology of Pulsating Stars
• Abundance analysis of seven delta Scuti Stars
• Study of Chemically Peculiar Stars-I : High-resolution Spectroscopy and K2 Photometry of Am Stars in the Region of M44
• An Ap star catalog based on LAMOST DR9
• A study of Pulsation & Rotation in a sample of A-K type stars in the Kepler field
• The search for roAp stars: null results and new candidates from Stroemgren-Crawford photometry
• On the spectroscopic nature of the cool evolved Am star HD151878