chromosphere
The chromosphere is a layer of the Sun's atmosphere located above the photosphere and below the corona. It is characterized by a reddish glow as seen during solar eclipses and is the region where solar filaments and prominences are observed.
Source: eclipse2017.nasa.gov
APODs including "chromosphere"
Perihelion Sun 2023
14/01/2023
Perihelion for 2023, Earth's closest approach to the Sun, was on January 4 at 16:17 UTC. That was less than 24 hours after this sharp image of the Sun's disk was recorded with telescope and H-alpha filter from Sydney, Australia, planet Earth. An H-alpha filter transmits a characteristic red light from hydrogen atoms. In views of the Sun it emphasizes the Sun's chromosphere, a region just above the solar photosphere or normally visible solar surface. In this H-alpha image of the increasingly active Sun planet-sized sunspot regions are dominated by bright splotches called plages. Dark filaments of plasma snaking across the solar disk transition to bright prominences when seen above the solar limb.