Location: Dubrovnik Croatia, on board the
Celebrity Cruises Galaxy.
GPS Coordinates provided by Brad Schaefer: 42 N 39' 57.2", 18
E 4' 44.3", Observer report by Bill Kramer, timing by Denise Kramer using
Casio wrist watch. Data is questionable, as readings differed significantly
amongst observers and the pre-calculated times.
Instrument: Coronado 40mm Hydrogen Alpha. f/10 (400mm
EFL), 8mm Brandon eyepiece with 2x barlow (Effective magnification: 100x)
2nd contact (local time is UT + 2)
07:34:09 - Inside chromosphere,
07:36:02 - Clearly inside chromosphere, edge of photosphere estimate.
Weather note: Clear sky, poor seeing through telescope. Image did
not hold steady and seem to jump around in the scope similar to vibration
effects. Heavy atmospheric turbulance suspected due to proximity of steep
hills and water at sunrise. Seeing became very steady about two hours
after 2nd contact. Estimated temperature about 65 degrees Farenheit.
3rd contact
13:04:09 - black drop starts,
13:04:26 - full circle not visible, black drop
13:05:01 - edge of photosphere
13:05:18 - nearing edge of chromosphere
13:05:53 - edge of chromosphere no longer seen.
Weather note: Clear sky, great seeing conditions. Estimated
temperature about 80 degrees Farenheit, almost directly overhead, excellent
view through the telescope.
Remarks: This was a very difficult observation.
Using hydrogen alpha the edge was "fuzzy" due to the spicules and some
light prominences. At 100x the view was shaky when people moved nearby
and it was very hard to see the edge of the chromosphere clearly.
At 2nd contact the seeing was poor due to the lower altitude in the sky
of the Sun and the proximity of nearby hills on the coast. As the
sun increased altitude seeing improved tremendously. Before the transit
started there was a large flare prominence visible north of the entry position
of Venus. The flare was not visible shortly after the transit started.
Using averted vision some additional detail in the chromosphere was
visible behind Venus however it was very faint and best viewed when the
image was positioned so that most of the photosphere was out of the view
and the blocking filter adjusted slightly.
I observed the entire event, start to completion, leaving the observing
area only on short trips to the Iced Tea dispenser and WC. It was
a warm day and I did switch to a bathing suit by the end of the six hour
event.
Most of the passengers and crew on the ship were not aware of the transit
in progress. I and others had offered to provide an educational program
but there was no interest from the cruise director. During the most
interesting moments of the transit the upper deck of the ship sported no
more than eight observers. Only two with modest telescopes.
Later that evening several other passengers reported seeing several telescopes
set up in the down town area with lines of a dozen or more waiting to look
through them. They were local amateur astronomers sharing the view!
Unfortunate for us not to have ventured out to meet them.
Conclusions to this exercise are that it would be very difficult to
get an accurate parallax measurement using just a few observers. Many would
be needed to average out the errors that persist in this observation.
Second, although quite rare, this event lacked visual impact except for
experienced solar observers who revel in the very movements of the heavens
above. A solar eclipse features a climax while a transit is in progress
most of the time. We are glad we saw it and look forward to the next. |