Delta Scuti stars in the Praesepe cluster observed by the MOST satellite

TL;DR

This study uses space-based photometry from the MOST satellite to identify pulsation frequencies in Delta Scuti stars within the Praesepe cluster, aiding asteroseismology by providing detailed frequency data.

Contribution

It presents new pulsation frequency measurements for four Praesepe Delta Scuti stars, including amplitude variability and frequency range analysis, using space-based observations.

Findings

Detected up to 34 frequencies per star.

Observed amplitude variability in one star.

Frequencies ranged from 0.76 to 41.7 c/d.

Abstract

The Praesepe cluster contains a number of Delta Sct and Gamma Dor pulsators. Asteroseismology of cluster stars is simplified by the common distance, age and stellar abundances. Since asteroseismology requires a large number of known frequencies, the small pulsation amplitudes of these stars require space satellite campaigns. The present study utilizes photometric MOST satellite measurements in order to determine the pulsation frequencies of two evolved (EP Cnc, BT Cnc) and two main-sequence (BS Cnc, HD 73872) Delta Sct stars in the Praesepe cluster. The frequency analysis of the 2008 and 2009 data detected up to 34 frequencies per star with most amplitudes in the submillimag range. In BS Cnc, two modes showed strong amplitude variability between 2008 and 2009. The frequencies ranged from 0.76 to 41.7 c/d. After considering the different evolutionary states and mean stellar densities of these four stars, the differences and large ranges in frequency remain.