On the approaching limb, prominences fortell of active regions about to rotate into view.
Image Info: Canon EOS D60 digital SLR, Coronado Solarmax90/T-Max, and 30mm blocking filter attached to a
Takahashi FS128 via T-mount TeleVue 2x (full-disk image) and 4x (quadrant image) Powermates. Processing
was done in Images Plus and final polishing in Adobe PhotoShop.
These hydrogen-alpha images were taken mid-morning on 14-Mar-2003 (North is up and East is to the left). A
darkened hub at the inner NW quadrant encircles the immense AR0306 complex, poised to unleash M-class flares
capable of disrupting communications. On the western limb, a prominence escapes from AR0300, lying now just
beyond the horizon. AR0311 churns directly beneath AR0306, trailing a string of relatively benign sunspot activity to
the east and a massive filament searing below, spanning most of the face as it points the way to a flurry of activity on
the opposite limb.
This and the lower-most image were originally processed using 3x3 binning, reducing the size so as to expedite the
procedure. Considerable detail was lost in the process however, as the Raw images did not exceed non-recoverable
limits (see Nyquist Sampling Theorem). The upper image has now been reprocessed as an unbinned image, and the
bottom one will be redone as time allows. AR0306 below, was cropped directly from the unbinned version above.
Having received several requests for a cropping of AR0306, I plucked the following from the above image. This is
very close to the camera's native resolution,
which at 3072 x 2048 and 72 dpi yields raw
images of over 42 x 28 inches, and thus lies at
the fringe of my focusing capabilities.
Real-time electronic focusing with a large
display would be quite a boon here, as I am
restricted to the precision of a 2.5x optical
focuser (and these old eyes aren't gettin' any
Being from a full-disk shot, low image
amplification was used. Had this region been
the actual target, a stacked pair of
Powermates (2x/4x) would have been the
weapon of choice. Quite a bit of detail is
present however, and one must take pause to
realize the sunspot's outline is the result of the
confluence of H-a emanations and NOT that
of a crisper white-light feature!
A smaller companion that has calved from the
main spot can be seen at the 11 o'clock