Year index to eclipses
The High Altitude Observatory of the National Center for Atmospheric Research has built an archive of
images of solar eclipses which are deemed to be of sufficient quality for research. The archive's properties can be
summarized as follows:
HAO will maintain this archive for the community's use and comments are welcome. In particular, we encourage others to
submit to us any data which might be included in this eclipse archive.
Interested parties should contact Don Kolinski.- The data begin from 1869 and extend to the present day.
- The data are from a diverse range of sources, but have been converted to a standard format.
- The data up to 1969 were all compiled by Jack Eddy between 1969 and 1971. Original plates were painstakingly photographed by Eddy and associates at HAO onto plates currently archived at HAO.
- Except for very recent data, most of the images are microdensitometered scans of the copies of original plates made by Eddy. No density-intensity calibration is available for these data.
- The data are therefore written into FITS files using just 8 bits per pixel.
- The images have only been crudely aligned such that the top of the images are solar North, and the right sides are solar West. This was done "by eye", and has an accuracy of 1 degree or so in rotation angle.
- The scales of the images, as stored in the FITS files, have been set so that the apparent lunar diameter, determined using the moon's limb, is very close to the ephemeris value. These "plate scales" are generally accurate only to a few parts per 1000.
An article briefly describes the archive and can be used as a reference to this database: "Historical eclipses and the recent solar minimum corona", by P. G. Judge, J. Burkepile, G. de Toma, and M. Druckmüller
Credits: In the late 1960s Jack Eddy took on the task of copying
photographically the original plates from a wide variety of sources.
In the 1990s Alice Lecinski and Kim Streander of HAO had many of
Eddy's plates scanned commercially. The National Center for
Atmospheric Research is sponsored by the National Science Foundation.
Any opinions, findings and conclusions or recommendations expressed in
this publication are those of the author(s) and do not necessarily
reflect the views of the National Science Foundation.
Key
Each image is labeled with the year of eclipse and an image number, starting from 0. The image number is just an index differentiating different images of the eclipse(s) occuring in each calendar year. Note that there can be 2 or more image numbers corresponding to a given archive plate, which may itself be one of 2 or more copies of an original exposure.Each image has the standard orientation (E=left, N=top) and are color-coded by the monthly average sunspot number (SSN): red (SSN less than 10); green (SSN greater than 10 but less than 50); and blue (SSN greater than 50).
To the right of each image are listed:
- observation location (observer)
- observation date
- original source type:
'plate' = photographic plate
'plate-Newkirk' = photographic plate using a Newkirk camera
'CCD' = CCD or CCD-like image
'CCD-Newkirk' = CCD or CCD-like image obtained using a Newkirk camera
'composite-XXX' = a composite of several images (XXX=CCD, plate, photo), combined in the manner described by: Druckmüller and associates.
original source:
'A' = University of Arizona
'H' = High Altitude Observatory
'HC' = Harvard College Observatory
'L' = Lick Observatory
'MD' = Miloslav Druckmüller
'MW' = Mount Wilson Observatory
'NR' = Naval Research Lab
'USNO' = US Naval Observatory - name of the scanned image file, which can be traced to the original plate via two pdf files:
The HAO coronal atlas, an index relating the particular digitized image to Eddy's particular plate, which itself refers to:
HAO coronal atlas logbook, Jack Eddy's handwritten log of his plates, showing which original plate was copied. - a note on the resource(s) used to identify the orientation of the images. (This note begins with an asterisk)
Example of what can be done
In this example, Dr. Miloslav Druckmüller selected images of differing exposures taken during the 1901 eclipse in Padang, Sumatra and processed them with modern techniques. The result is shown below. It's usefulness in studying coronal morphology is evident.
Left: Example of the original images taken in 1901; Right: Miloslav Druckmüller's processed version.
Dr. Druckmüller's image processing techniques also produce astounding results
when used with modern digital photographs having a high dynamic range. Here is an example of his work on the 2009 eclipse in the Marshall Islands.
Jeur India (Henry Cousens)
22-Jan-1898
Scanned photo from family collection
* Personal correspondence with Angela O'Sullivan, granddaughter of photographer Henry Cousens
Download: [TIFF]
22-Jan-1898
Scanned photo from family collection
* Personal correspondence with Angela O'Sullivan, granddaughter of photographer Henry Cousens
Download: [TIFF]
