Hello all,
I’ve been able to steal a few moments over the last couple
of weeks to sketch Sol.
This is turning into a wonderful journey for me with the
Sun. I am not just marvelling at its
ever changing surface. It has also
spurred me onto learning about our parent star. I never thought nuclear fusion could be such a
spectacular topic!!!
August 18 gave me a very active limb and chromosphere
quarter section. The chromosphere
(surface of the Sun) was riddled with fine filaments (prominences seen over the
surface), plages and sunspots. The limb
had an assortment of prominence types – arch, platform arches, & a pyramid. Also a lovely long spicule.
Yesterday was a race to beat the approaching clouds and
rain. The race became more intense as
the Sun had two wonderful areas of activity on the go, but on opposite sides of
the disk. As things turned out, I was
only able to complete only one of the two sketches I hoped to accomplish. Better something than nothing…
The second sketch presented here shows two different stages
of prominence development. The brighter
part on the lower right shows mature platform prominences. They are called platform as they exhibit a flat,
table like roof where high energy plasma is racing through the magnetic fields
on the surface of the Sun. There are two
platform prominences here, with a smaller & brighter one underneath the
taller but thinner one above it. The larger
top prominence stretched out into an ever diminishing ribbon, to then frazzle
out into shredded pieces. A really
lovely spectacle to follow through off fine details.
Plasma, for folks who may not be familiar, is a gas that has
been heated to such a high temperature that its outter layer of an electron (in
the case of Hydrogen) or electrons (for Helium), have been ripped off. The result is a gas that is electrically
charged, and so is affected by the strong magnetic fields that develop on the
Sun’s hot surface. These magnetic fields
channel these plasma gases through what we see as tube like arches –
prominences! These magnetic fields are
not stable and permanent features on the Sun, appearing and disappearing all
the time, that can last between hours through to weeks. And as these magnetic fields fluctuate, the
prominences change in shape.
Large prominences, when they finally collapse, can create
magnificent and enormous plume of plasma that billow out from the sun out into
space. We commonly know these as
flares. I’ll describe how these flares
manifest themselves here on Earth another time, and how they can knock out electrical
networks.
But be they large or smaller prominences, when they do
collapse, the material that is released is known as a Coronal Mass Ejection
(CME). There is an intermediate step in
prominence evolution, but we’ll deal with these later when I am able to sketch
on of these.
It is the disintegrating stages of one of these coronal mass
ejections that we see on the upper left.
We see just the remaining columns of plasma that is being held in place
by the weakening magnetic fields. When I
started this sketch I had been able to spot some of the plume of escaping
plasma being launched off into space. I
should have sketched this section first, rather than the platform prominences,
for when I returned to the CME, that plume was too faint to see through the incoming
thin cloud. Oh, well, lesson learnt…
Both sketches were done using the same equipment:
Scope: ED80 f7.5
refractor
Gear: Daystar Quark,
25mm plossl, 101X
Dates: 18th
August & 3rd September, 2015
Location: Sydney,
Australia.
