Pulsation of EE Cam

TL;DR

This study investigates EE Cam, a Delta Scuti star with intermediate pulsation amplitudes, by analyzing extensive photometric data and spectra to understand its pulsation modes and rotational properties.

Contribution

The paper provides detailed frequency analysis and mode identification of EE Cam, highlighting its transitional nature between HADS and normal Delta Scuti stars.

Findings

15 significant pulsation frequencies identified

Dominant radial mode at 4.934 cd$^{-1}$ confirmed

Star's rotational velocity measured as 40 km/s

Abstract

EE Cam is a previously little studied Delta Scuti pulsator with amplitudes between those of the HADS (High-Amplitude Delta Scuti stars) group and the average low-amplitude pulsators. Since the size of stellar rotation determines both which pulsation modes are selected by the star as well as their amplitudes, the star offers a great opportunity to examine the astrophysical connections. Extensive photometric measurements covering several months were carried out. 15 significant pulsation frequencies were extracted. The dominant mode at 4.934 cd$^{-1}$ was identified as a radial mode by examining the phase shifts at different wavelengths. Medium-dispersion spectra yielded a $v\sin i$ value of $40 \pm 3$ km s$^{-1}$. This shows that EE Cam belongs to the important transition region between the HADS and normal Delta Scuti stars.