| |
 |
| Paper: |
A Sharp Look at Coronal Rain with Hinode/SOT and SST/CRISP |
| Volume: |
455, 4th Hinode Science Meeting: Unsolved Problems and Recent Insights |
| Page: |
253 |
| Authors: |
Antolin, P.; Carlsson, M.; van Voort, L. R. d.; Verwichte, E.; Vissers, G. |
| Abstract: |
The tropical wisdom that when it is hot and dense we can expect rain
might also apply to the Sun. Indeed, observations and numerical
simulations have showed that strong heating at footpoints of loops, as
is the case for active regions, puts their coronae out of thermal
equilibrium, which can lead to a phenomenon known as catastrophic
cooling. Following local pressure loss in the corona, hot plasma
locally condenses in these loops and dramatically cools down to
chromospheric temperatures. These blobs become bright in Hα and
Ca ii H in time scales of minutes, and their dynamics seem to
be subject more to internal pressure changes in the loop rather than
to gravity. They thus become trackers of the magnetic field, which
results in the spectacular coronal rain that is observed falling down
coronal loops. In this work we report on high resolution observations
of coronal rain with the Solar Optical Telescope (SOT) on
Hinode and CRISP at the Swedish Solar Telescope
(SST). A statistical study is performed in which properties
such as velocities and accelerations of coronal rain are derived. We
show how this phenomenon can constitute a diagnostic tool for the
internal physical conditions inside loops. Furthermore, we analyze
transverse oscillations of strand-like condensations composing coronal
rain falling in a loop, and discuss the possible nature of the
wave. This points to the important role that coronal rain can play in
the fields of coronal heating and coronal seismology. |
|
|
|
|
|
