The strata of the solar atmosphere are very opaque compared with the terrestrial atmosphere.
Such limb darkening occurs because the solar atmosphere increases in temperature with depth.
He did research on the internal constitution of the stars and contributed to the understanding of the solar atmosphere.
Laplace imagined that the planets had condensed from the primitive solar atmosphere, which originally extended far beyond the limits of the present-day system.
The helium of the cooler outer parts of the solar atmosphere absorbs the characteristic light frequencies from the lower and hotter regions of the Sun.
"We can determine exactly where and when energy is released in the solar atmosphere," he added, "and identify its form: plasma heated to tens of millions of degrees".
This was done by measuring the velocity and direction of acoustic waves in the Sun's photosphere, the surface-like zone in the dense solar atmosphere.
Just prior to this event, the chromosphere, a thin bright red layer in the lower solar atmosphere, appears for a few seconds at the edge of the Sun's disk.
NASA's Transition Region and Coronal Explorer (TRACE), by contrast, will explore the three-dimensional magnetic structures that emerge through the photosphere, and will work out the shape and dynamics of the upper solar atmosphere.
The solar atmosphere is actually a vacuum by most standards; the total density above any square centimetre is about 1 gram, about 1,000 times less than the comparable mass in the atmosphere of Earth.
A. A coronagraph is an optical device that blocks the light from the sun's disk, making it possible to observe the corona, the very thin and hot upper level of the solar atmosphere, at the edge of the disk.
