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SAAO photographic plate store destroyed  @psychohistorian.org

SAAO photographic plate store destroyed

posted: 4626 days ago, on Friday, 2007 Sep 28 at 16:20
tags: astronomy, SAAO, history, astrophotography, LMC/SMC.

During 2007, the plate store at SAAO, Cape Town, was refurbished to make room for a new computer centre. The several thousand photographic plates had to be removed. Instead, the majority were simply destroyed.

The plate store was quiet well organized. There were two types of metal storage cabinets: tall, ceiling-high ones, containing standard Kodak 103a-O-sized plates, and four smaller cabinets with Radcliffe plates (see the photo gallery below).

Two of the smaller cabinets, containing Radcliffe spectra, were moved to Dr Dave Kilkenny's office for eventual storage. The two cabinets containing the Radcliffe Newtonian plates (direct images), were left in the plate store, along with the rows of tall cabinets.

Most of these tall cabinets contained plates taken for the Cape parallax effort, for which the sky was divided into zones and each zone photographed a number of times. Other cabinets contained more "interesting" plates. For example, the original glass negatives used to compile the TVMPSA (True Visual Magnitude Photographic Star Atlas) by Christos Papadopoulos of Pretoria, were stored here. Ian Glass and I moved these to the archive building and Ian subsequently shipped them to Stellarum in Germany where they will be digitized.

When it became clear that all the remaining photographic plates were to be destroyed, I removed the two Radcliffe cabinets, and as many of the remaining plates as could be managed. With the help of Gustav and Basil, we finally managed to secure them safely in my study.

The Radcliffe plates are being carefully digitized as and when I get the time. A photographic light table provides the illumination, and a Canon S3-IS digicam captures the images in raw format. The digital images will eventually be processed, catalogued and made available online. The original glass plates will then be returned to the SAAO where a special area has been set aside for their safe-keeping.

From the tall cabinets, a total of 1,137 plates were carefully (but hastily) removed. These, too, are now safely in my study. They have been sorted and catalogued.

By broad category (with the number of plates in brackets) there are images of: various Collinder, Melotte and Trumpler clusters (21), the Coal Sack (6), wide-field images of selected areas within Sagittarius (274), NGC objects (556), IC objects (49), LMC and selected Regions within it (68), and SMC Regions (7). Also photographed was the Moon (55), the Great Comet of 1901 (1), Mars (1), and Saturn and its moons (15). Some 204 individual objects were imaged.

The oldest plate in the collection was taken on 20 March 1892, of eta Argus (NGC 3372). The most recent plate was taken on 24 February 1987, of SN 1987A in the LMC, by Joe Churms.

This collection represents a total exposure time of 57,078 minutes, or 39.63 days.

Slide show

 2007 September 11. Besides the rows of roof-high cabinets there were four steel cabinets containing Radcliffe Newtonian photographic plates (direct images) and Radcliffe Coude spectrographic plates.  [click to start slide show]

nothing more to see. please move along.

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