Solar Radius Variations from Solar Eclipse Observations - Updated 2007 Sept. 5

The 2005 poster paper presentation described below was updated and expanded for my presentation at the Solar Eclipse Conference 2007 that was held last weekend at the Griffith Observatory in Los Angeles, California; it is here (3 megabytes). The mu Arietis graze movie that I showed at the start of my talk is here (a large .avi file, over 300 megabytes); more about that interesting grazing occultation is here. There are some errors in our solar radius results due to a format conversion problem that was discovered shortly before the conference. The affected data will be re- analyzed and more comprehensive eclipse radius results tables prepared so that updated information can be posted here probably sometime in October - sorry for the delay, there's more work left to do than I thought. Also soon (may be a week to 10 days) I'll add here .avi files of some of the videos that have been obtained near the edges of total and annular solar eclipse paths.

Since making the presentation, I think that the situation with filtered video observations might not be as bad as I indicated in it. But I think that the observations should use less filtration than we've been using, that we should reach the lowest levels of the photospheric intensity, which would be done if we can record some of the chromosphere as well as the photosphere (recording in color might be even better for this, to see the color transition). I think then that it should be possible to compare video observations better with other types of observations, including direct visual observations, which is all we have for the old eclipses.

My impressions of the interesting conference are here.

[the sections below were written in 2005 or earlier]

I gave a poster presentation, "Accuracy of Solar Radius Determinations from Solar Eclipse Observations, and Comparison with SOHO Data", at the 3rd annual Solar Radiation and Climate Experiment (SORCE) Science Meeting, with theme "Paleo Connections Between the Sun, Climate, and Culture", in Durango, Colorado, Sept. 14 - 16. The poster was in the form of 16 panels in a Power Point file here. For an overview, see panels (or "slides") 10 (a plot of the eclipse and some other radius measurements) and 16 (the last one with a summary of the main conclusions and some recommendations), while panel 8 lists the observers whose data were used in the new analyses and panel 9 is a summary list of the results. James Thompson, now a student at the University of Virginia, performed the new analyses working with me from early June to mid-August with support from NASA. Some with older versions of Power Point can't open the file; a version in the 1997 format is here (larger, 8 megabytes).

First results of the 2004 December 4th total solar eclipse in southern Australia are here

Some information about the 2000 December 25th partial solar eclipse in North America is here.

Last updated 2007 September 5 David Dunham, President, I.O.T.A. Phone: home 301-474-4722 office 240-228-5609 car 301-526-5590 e-mail dunham@starpower.net (home) and david.dunham@jhuapl.edu (office)