Observations from Moore Observatory, Washington
- Updated 2007 April 2, 17h UT
This now includes a link to Michael Richmond's analysis of the
observations and a new item on the best estimate of the times of the
observations.
This northernmost observation seems to show a flat bottom indicating
an occultation of almost 4 min. by the "solid" surface of Pluto
Tony George has supplied his best estimates of the Universal Times
of the images obtained at the Moore Observatory here.
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To: IOTAoccultations@yahoogroups.com
From: "Stupendous_Mn"
Date: Wed, 28 Mar 2007 02:07:47 -0000
Subject: [IOTAoccultations] Photometry of Pluto occultation from
Tony George's record
Tony George kindly made available copies of the images from
observations of the recent occultation of Pluto. I have analyzed the
images and written a brief report. See
http://spiff.rit.edu/richmond/occult/pluto_mar2007/pluto_mar2007.html
My measurements show the occultation clearly. The time of ingress
could be measured well, but the egress appears to occur roughly at
the end of the dataset; I can't tell if it occurs before or after
the measurements.
Tony will be able to attach times to the frame indices, I trust.
Michael Richmond
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To: Tony George; 'FR Paris Obs Bruno Sicardy'
Cc: 'David Dunham'; rickf@stick.net; 'Maley, Paul D. (JSC-
DO141)[USA]'; 'TX Houston home Paul Maley'; 'DeeMuenchen Wolfgang
Beisker'; Michael Richmond IOTA
Subject: RE: NASA JSCAS Pluto detail - Pluto graze farther north?
Was center north or south??
Tony,
I think that you've mis-identified the occultation on your
plot. The central occultation was predicted (my combined
prediction) to occur at 10:50.0 UT at the Moore Observatory, but the
MMT observations in Arizona showed that the occultation occurred 4.8
min. late relative to that prediction, with that shift confirmed by
all other observations where the event could be timed. I think the
occultation is in your recording, from just after 3:53 to just after
3:56 local time; there's even a hint of a central flash at the right
time, 3:54.8 [but that is probably not really the central flash,
since it was likely not visible anywhere from the Earth's surface,
according to Bruno Sicardy's analysis]. Did you observe beyond
3:56.5? [in a later message, he said that they did not observe after
3:56.5] Of course, this then leaves unanswered the cause of the
deeper drop from 3:49 to 3:52 that you highlight on your recording;
maybe there was some cirrus at the approximately 13 deg. altitude
above the horizon then? [Tony said that conditions were good, no
clouds were apparent].
David
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From: Tony George [mailto:triastro@oregontrail.net]
Sent: Friday, March 23, 2007 12:04 AM
To: Dunham, David; 'FR Paris Obs Bruno Sicardy'
Cc: 'David Dunham'; rickf@stick.net; 'Maley, Paul D. (JSC-
DO141)[USA]'; 'TX Houston home Paul Maley'; 'DeeMuenchen Wolfgang
Beisker'; Michael Richmond IOTA
Subject: RE: NASA JSCAS Pluto detail - Pluto graze farther north?
Was center north or south??
Hello all,
My data is preliminary. I'm very new at trying to reduce .fts
images. I had to learn how to use CCDSoft to do so. I made a few
mistakes as well. We didn't start recording images early enough.
We were bit late in acquiring Pluto and then so busy trying to get a
good focus that we started imaging a bit late. Also, I didn’t know
that Envisage with the Meade Autostar Suite would not automatically
store the computer time and date on the .fts files, so I don’t have
a good time base. It was approximately 10:48 UT when I looked at my
watch and realized we were going to be late and started imaging. We
had a very low altitude and while the image was a bit fuzzy at
times, we did have a continuous view of Pluto and the target star
throughout the observation. Each image is 4 seconds long.
The raw data are stored here:
Here is a chart I made reducing my data as best I could:
I think it does show a "flat bottom" to the occultation.
Here is the Excel file that includes several different sheets and
graphs that I used when processing the data. I can sort any of this
out for anyone that has any questions, but I’m guessing that for
those of you like Mr. Sicardy, you will be better off just
downloading my images and making the best of the data as you know
how to do. I’m also cc:ing Michael Richmond on this message, as he
has independently verified some of my observations in the past and
he may want to give this data set a try.
I would certainly like to receive any results that others have
provided. I would like to receive copies of any final reports
produced. I appreciated the professional community inviting us
amateurs to participate in such an interesting event. With
practice, I think we could do substantially better in the future.
Best regards to all,
Tony George
Umatilla, Oregon