Explanation:
Enjoying Wednesday's
transit
of Mercury from Dallas, Texas, astronomer Phil Jones recorded
this detailed image of the Sun.
Along with a silhouette of the innermost planet,
a network of cells and dark
filaments can be seen against
a bright solar disk with spicules and
prominences along
the Sun's edge.
The composited image
was taken through a telescope equiped with an H-alpha filter
that narrowly transmits only the red light from
hydrogen atoms.
Such images emphasize the
solar chromosphere,
the region of the Sun's atmosphere immediately above
its photosphere or normally visible surface.
Left of center, the tiny disk of Mercury seems to be
imitating a small sunspot that looks a little too round.
But in H-alpha pictures,
sunspot regions are usually dominated by bright splotches (called
plages) on the
solar chromosphere.
