Search of Secondary Pulsation Modes: Globular cluster (NGC 6496)

TL;DR

This study employs Fourier analysis to identify secondary pulsation modes in variable stars within globular cluster NGC 6496, revealing two confirmed modes and addressing complexities in variable star behavior.

Contribution

It introduces a method to detect secondary pulsation modes in globular cluster variables using Fourier analysis and smoothing techniques, providing new insights into their pulsation characteristics.

Findings

Identified two secondary pulsation modes in variables V1 and V2.

Matched multi-band periodic values with existing literature.

Improved phase curve smoothness using moving average methodology.

Abstract

The Fourier-discrete-peridogram are used to identify pulsation modes in variables. We have found two pulsation modes in V1 and V2 among 13 new variables as described by Abbas et al.. The five variables V9 to V13 are not shown close to periodic values by analysis of the frequency distribution of multi-band data and also create difficulty to describe their varied nature. The multi-band periodic values of V1 and V6 are matched with known literature values. The scattering of the varied nature of secondary pulsation modes is eliminated by moving average methodology. The phase curve of secondary mode is found to be more smooth compared to a prominent mode of pulsation.