The Total Solar Eclipse in the Pacific, April 8, 2005 -
as seen from the MV Discovery
Baily's Beads Galore! But little more ...
These 31 pictures are re-centered blow-ups from images taken on
chemical film during the 2nd and 3rd contacts of the Hybrid Solar
Eclipse of April 8, 2005, from 129°39' West and 22°37'
South (way North of the Oeno atoll in the Pitcairn islands) - where
the eclipse was total for half a minute.
Approaching the 2nd contact
Working from the Lido Deck of the MV Discovery I used the
trusted 1 meter f/10 Russian Maksutov telephoto lens - as seen
e.g. in a report from the TSE of 2001
- as the main instrument, shooting through very thin clouds and
trying hard to compensate for the pitching motion of the ship of
sometimes several degrees (while the stabilizers fortunately took
out nearly all rolling motion).
After 3rd contact (first row left -> right, 2nd row l -> r)
I was using Fujicolor 400 film (kindly supplied by M.
Druckmüller), exposure times of 1/1000 sec nearly all of the
time - and one layer of thin and extremely cheap solar filter (the
famous Rettungsfolie found in every German car First Aid Kit).
Having used 2 layers for monitoring the partial phases, I had
pulled down one layer for better results on the faint, small Baily's
Beads. And then, mesmerized by the colorful sky spectacle,
forgotten to pull the 2nd layer during totality, too ...
Time runs from botton to top on the lefttowards 2nd contact
and on the right from top to bottom after 3rd contact
It turns out the combination of thin filter, f/10 optics and 400
speed film was just about right for the fascinating Baily's Beads
but too dense to show much of the chromosphere (only faintly
visible in the two shots just after 3rd contact which were exposed
a bit longer but are also less sharp) and any hint of the
prominences and the corona. (Those missing phenomena were
fortunately captured nicely by a - wildly shaking - video camera
mounted in parallel with the Maksutov; stills may be made
available later.)
Lessons aplenty from my very first TSE observation
attempt from a cruise ship (see also this
report for a very different experience during the 2002
annular off Mexico ...) and the 12th total eclipse of the sun overall
can be drawn already:
- The learning curve - which had somewhat matured for my
land-based eclipses in the late 1990's after 7 or so tries - has
started all over again, with lots of weird mistakes made and pretty
unexpected results. Then again we were facing the most
challenging possible combination of a rocking ship and an
incredibly short TSE which will not repeat for a long time, I
suppose (and hope) ...
- It can be done even in the middle of the Pacific where
the Sun swings around by several degrees, but keeping the
eclipsed Sun nicely centered would require a tripod contruction
both stable and moving gently, with some kind of
additional aiming device (missing here). Given the short duration
of totality, the usual solution for ship-bound observers of just
waiting for the Sun to just "come back" into the f.o.v. was not
possible.
- Even without an optimized mounting and under the shaky
Discovery conditions, shooting at 1/1000 will get you nearly
perfectly sharp pictures at 1 meter focal length - this was the
most positive surprise from the 2005 HSE experience! Without
filters and on fast film high-resolution pictures of the
chromosphere, prominences and inner corona as good as from
dry land are thus possible (as has indeed been proven by a few
others on the ship, with both chemical film and digital still
photography).
- The accidental use of the thin filter (the density of which is
still TBD; you can easily see a normally lit landscape through it)
highly improved the visibility of the fascinating Baily's Beads
which were particularly enhanced by the small difference between
the Moon's and the Sun's diameters. Without that filter they
would have been burned into the film (while with a regular-density
solar filter they would have been underexposed): That's why I
chose the tricky 2-layer technique in the first place, following
good results during a thin-ring annular eclipse in
1999.
Thus the 2005 HSE by pure chance has turned into an important
dress rehearsal for the 2005 ASE ½ year later in Tunisia ...
- According to many reports this was not your typical ship-
bound eclipse: In many previous cases ships have presented much
more stable platforms, suitable for long-focus exposures up to 1/8
of a second. Still, whenever given the choice of a ship or dry land, I
would probably always opt for the latter: You can expose as
long as you like, the Sun doesn't try all the time to exit your f.o.v.
(forcing you to waste time to recenter it), and decent videography
at high magnification is also possible. But being able of
travelling to the ground observing site by cruise ship could
be very tempting ... !
More information about the 2005 HSE experience can be found in
numerous e-mails sent to the SEML before
& during the cruise, a detailled timeline of the whole journey and a
collection of links put together
in advance - and the Cosmic Mirror
# 288 has many links to other reports about the
eclipse from this and other ships as well as from the Americas,
where it was either annular or partial or clouded out!
Daniel Fischer, April 25, 2005
