Harvard Plate Collection Metcalf Telescope

Digital Access to a Sky Century @ Harvard
A New Look at the Temporal Universe

Plate Classes

Every plate is assign a class designation to indicate the type of exposure that was taken. The following table comes primarily from the Harvard Annals, Vol 26, page 9. This list is divided into three groups, indicated by the Notes column below:

The list from the above references is incomplete and does not account for all of the classes that appear in the database. These additional classes are marked with the derived note and given a description that follows the examples given in the above reference. Nevertheless, there are still several classes that must be marked unknown class until additional information is available

Curator Alison Doane notes that chart plate is an ordinary plate that documents the sky, like a patrol plate.