Prominence seismology using small amplitude oscillations

TL;DR

This paper reviews the use of prominence seismology to analyze small amplitude oscillations in solar prominences, combining observations and magnetohydrodynamic models to infer physical properties of prominence fine structures.

Contribution

It discusses the first seismological applications to prominences and advances in understanding the damping of prominence oscillations.

Findings

Small amplitude oscillations are associated with fine prominence threads.

Oscillations damp within a few periods and do not affect entire prominences.

Theoretical models help interpret observed oscillation properties.

Abstract

Quiescent prominences are thin slabs of cold, dense plasma embedded in the much hotter and rarer solar corona. Although their global shape is rather irregular, they are often characterised by an internal structure consisting of a large number of thin, parallel threads piled together. Prominences often display periodic disturbances mostly observed in the Doppler displacement of spectral lines and with an amplitude typically of the order of or smaller than 2--3 km s$^{-1}$, a value which seems to be much smaller than the characteristic speeds of the prominence plasma (namely the Alfv\'en and sound velocities). Two particular features of these small amplitude prominence oscillations is that they seem to damp in a few periods and that they seem not to affect the whole prominence structure. In addition, in high spatial resolution observations, in which threads can be discerned, small amplitude oscillations appear to be clearly associated to these fine structure constituents. Prominence seismology tries to bring together the results from these observations (e.g. periods, wavelengths, damping times) and their theoretical modeling (by means of the magnetohydrodynamic theory) to gain insight into physical properties of prominences that cannot be derived from direct observation. In this paper we discuss works that have not been described in previous reviews, namely the first seismological application to solar prominences and theoretical advances on the attenuation of prominence oscillations.