2003/05/20 by Santosh Joshi, V. Girish, R. Sagar +10 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2003.06823.x
published as Mon.Not.Roy.Astron.Soc. 344 (2003) 431 · 9 pages, 6 Figures, Accepted for publication in MNRAS
arxiv created 2003/05/20 · openalex publication_date 2003/09/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The chemically peculiar (CP) stars HD98851 and HD102480 have been discovered to be unusual pulsators during the “Naini Tal Cape Survey ” programme to search for pulsational variability in CP stars. Time series photometric and spectroscopic observations of these newly discovered stars are reported here. Fourier analyses of the time series photometry reveal that HD 98851 is pulsating mainly with frequencies 0.208mHz and 0.103mHz, and HD102480 is pulsating with frequencies 0.107mHz, 0.156mHz and 0.198 mHz. The frequency identifications are all subject to 1 d−1 cycle count ambiguities. We have matched the observed low resolution spectra of HD 98851 and HD102480 in the range 3500-7400˚A with theoretical synthetic spectra using Kurucz models with solar metallicity and a micro-turbulent velocity 2 kms −1. These yield Teff = 7000 ± 250K, logg = 3.5±0.5 for HD 98851 and Teff = 6750±250K, logg = 3.0±0.5 for HD 102480. We determined the equivalent H-line spectral class of these stars to be F1IV and F3III/IV, respectively. A comparison of the location of HD98851 and HD 102480 in the HR diagram with theoretical stellar evolutionary