PREDNASAJUCI / LECTURER :

Zurab Vashalomidze

(1) Astronomical Institute, Slovak Academy of Sciences,
059 60 Tatranská Lomnica

NAZOV / TITLE :

Imaging Spectroscopy of Coronal Rain with the Swedish 1-m Solar Telescope and
the Interface Region Imaging Spectrograph


ABSTRAKT / ABSTRACT :

We present coordinated multiwavelength observations of coronal rain associated
with both an active region and a nearby coronal cloud, observed on 14 June 2023
using the Swedish 1-m Solar Telescope (SST) and the space-borne Interface Region
Imaging Spectrograph (IRIS). The SST dataset includes high-cadence observations
in the Ca II 8542 A, Halpha, and He I D3 lines, complemented by IRIS slit-jaw
images centered at 1330 A and 2796 A, and Mg II k & h spectral rasters.
The one-hour observing sequence captures multiple episodes of cool plasma
condensation and drainage along coronal loops, showing strong temporal and
spatial correlations between chromospheric and transition-region diagnostics.
While plasma blobs of coronal rain are clearly visible in Halpha, they are
notably absent in Ca II 8542 A and He I D3. The SST Halpha and IRIS
observations reveal accelerating downward plasma motions consistent with
radiatively cooled condensations forming in thermally unstable coronal loops.
Subsequent Halpha brightenings of some plasma blobs may be partly due to
Doppler brightening, likely associated with Doppler dimming in Mg II k & h.
These coordinated SST–IRIS observations provide new constraints on the coupling
between chromospheric and coronal plasma during the coronal rain cycle,
offering insights into mass transport in active regions and coronal clouds.