The size of fine structures in the quiescent prominence that appeared on August 16, 1992 has been estimated using power spectra generated from intensity variations of Ha images of the lower part of the prominence, which were taken with a G1 CCD camera attached to 25cm coronagraph at Norikura Coronal Station in Japan. The lower part of the prominence has shown a distinct intensity variation with optical thickness of τ=1~5. Our analysis yields a mean size of fine structures ranging from 350 km to 1,000 km, in good agreement with Hirayama(1985) and Zirker & Koutchmy(1989, 1991).

To study kinematics of solar prominences, we have made Ha spectrographic study of an eruptive prominence which appeared on the 27th of August, 1992 with a position angle of 270 deg. The observation was carried out by a Littrow type spectrograph and a G1 CCD camera attached to the 25cm coronagraph at Norikura Coronal Station. In taking the spectral data the slit was placed in parallel to the solar limb at 7 different heights, each being separated by 5 arcsec with a time step of 30 sec. The observed eruptive prominence shows a wide range of line of sight Doppler velocity, spanning from Vdopp=−17.5km/stoVdopp=58.2km/s Vdopp=−17.5km/stoVdopp=58.2km/s . It is also found that the velocity increases with height at the rate of ΔV=0.86km/s/arcsec ΔV=0.86km/s/arcsec .

A quantitative analysis has been made to estimate the horizontal variation of physical parameters in a loop type active prominence by analyzing Call H&K and Hε… Hε… spectra taken from such an active prominence (appeared on May 23, 1981 with position angle 251 degree) with Littrow type spectrograph attached to 25cm coronagraph at Norikura Coronal Station of National Astronomical Observatory of Japan. The spectral resolution is 1.12A/mm and the spatial resolution is 25'/mm for Call H&K lines. The present study shows that the turbulent velocity ranges from 10km/s to 20 km/s in the loop prominence, which are in good agreement with those of Hirayama (1989). It is also found that the temperature of the loop prominence is higher than that of quiescent prominences(\~8,000K) (\~8,000K) by about 4,000 K, whose temperature deviation seems very high.

To derive coronal temperature, electron density and nonthermal velocity, we have analyzed high resolution spectra (e.g., Fe XII 338.3, Fe XII 352.1, Fe XIV 334.2, Fe XIV 353.8, Fe XV 284.2, Fe XV 321.8, Fe XV 327.0, Fe XVI 335.4, and Fe XVI 360.8) taken from AR 6615 by SERTS (Solar Extreme Ultraviolet Rocket Telescope and Spectrograph). Important findings emerging from the present study are as follows: (1) Temperature estimated from Fe XVI 335.4 and Fe XIV, 334.2 is ~2.4 × 106 K and no systematic difference in temperature is found between the active region and its adjacent quiet region; (2) Mean electron density estimated from Fe XV is ~3 × 109 cm -3 and ~10 10 cm-3 from Fe XII and Fe XIV; (3) Mean density of the active region is found to be higher than that of the quiet region by a factor of 2; (4) Nonthermal velocity estimated from Fe XV and Fe XVI is 20 ~ 25 km s-l which decreases with increasing ionization temperatures. This supports the notion that the nonthermal velocity declines outwards above the transition region.

An attempt has been made to examine the characteristics of acoustic and MHD waves generated in stellar convection zones( 4000 K ≤ T e f f ≤ 7000 K , 3 ≤ log g ≤ 4.5 ). With the use of wave generation theories formulated for acoustic waves by Stein (1967), for MHD body waves by Musielak and Rosner (1987, 1988) and for MHD tube waves by Musielak et al.(l989a, 1989b), the energy fluxes are calculated and their dependence on effective temperature, surface gravity and megnetic field strength are analyzed by optimization techniques. In computing magneto-convection models, the effect of magnetic fields on the efficiency of convection has been taking into account by extrapolating it from Yun's sunspot models(1968; 1970). Our study shows that acoustic wave fluxes are dominant in F and G stars, while the MHD waves dominant in K and M stars, and that the MHD wave fluxes vary as T 4 e f f ∼ T 7 e f f in contrast to the acoustic fluxes, as T 10 e f f . The gravity dependence, on the other hand, is found to be relatively weak; the acoustic wave fluxes ∝ g − 0.5 , the longitudinal tube wave fluxes ∝ g 0.3 and the transverse tube wave fluxes ∝ g 0.3 . In the case of the MHD body waves their gravity dependence is found to be nearly negligible. Finally we assesed the computed energy fluxes by comparing them with the observed fluxes F o b of CIV( λ 1549 ) lines and soft X-rays for selected main sequence stars. When we scaled the corrected wave fluxes down to F o b , it is found that these slopes are almost in line with each other.