In the very last seconds before (and first seconds after) a total solar eclipse Prominences can be seen (if there are any that day).

In this photo from the 2019 Total Solar Eclipse in Chile they are visible.
These Prominences – seen at the bottom, top and right – are energi bursts that looks like red flames – and they are many times larger than Earth!

The long red line at the right side of the sun are the end (or beginning) of Baily’s Bead’s (see here: Baily’s Beads and Chromosphere) which are sun light rays shining through the valleys of the Moon.
Here they are still obstructed by the mountains of the Moon, so what we see here is the second layer of the SUn’s three layers of atmosphere; the Chromosphere, which only visible at total solar eclipses!
The layer beneath the Chromosphere is the Photosphere (what we call the “surface” if the sun) which is many times brighter than the Chromosphere and thus overshines it without a total solar eclipse (even with special equipment it’s not visible)!

The photo was taken of the 2019 Total Solar Eclipse in Chile from the European Southern Observatory (ESO) at La Silla Observatory in the Atacama Dessert.