Short-Period Oscillations Found in a Quiescent Prominence

Abstract

Abstract For the purpose of detecting periodic oscillations or waves in a quiescent prominence, time-series observations of Ca II K line spectra were carried out at the Hida Observatory. Detailed line-profile analyses followed by power spectral analyses have led to the conclusion that nearly the same phase of periodic oscillations, having a period of 160 s and an amplitude of 0.8-1.4 km s-1, were found in the line-of-sight Doppler velocity at successive locations over 15,000 km along the spectrograph slit. The intensity showed a slight indication for periodic fluctuations with a period of 240 s. In the line width, however, no periodicity was detected both from the direct inspection of temporal variations and from the power spectral analysis.