Slow Magnetoacoustic Oscillations in Stellar Coronal Loops

TL;DR

This paper investigates how gravitational stratification affects slow magnetoacoustic oscillations in stellar coronal loops, revealing that stratification influences density perturbations and slightly lengthens oscillation periods, aligning with observed stellar pulsations.

Contribution

It provides a numerical analysis of stratified stellar coronal loops, highlighting the impact of star mass, temperature, and loop length on oscillation properties, which was not previously detailed.

Findings

Stratification causes greater differences in density than velocity perturbations.

Oscillation periods are slightly longer in stratified loops compared to non-stratified ones.

Calculated periods match observed stellar pulsation ranges in X-ray and white light.

Abstract

Slow magnetoacoustic oscillations in stellar coronal loops with gravitational stratification are analyzed with a numerical solution of the boundary-value problem for eigenvalues and eigen functions. In this study, we only focus on the resonant periods. The effects of the gravitational stratification, star mass, loop temperature, and loop length on the properties of slow magnetoacoustic oscillations are investigated. It is shown that the discrepancy between stratified and non-stratified loops is higher in density perturbations than velocity perturbations. When the star has larger mass, higher coronal temperature, and longer loop, the density perturbations in stratified loop are significantly different from the harmonic functions. The periods in the stratified loop are slightly longer than in the non-stratified loop. The periods calculated in our model (14-644 min) are consistent with the periods of stellar quasi-periodic pulsations observed in both soft x-rays (2-70 min) and white lights (8-390 min).