HCO: Photographic Plate Collection Descriptions
- Patrol plates - filed by region
- RH, RB, etc. - scale 390"/mm (roughly equal to SAO charts);
limiting magnitude 14-15; roughly 100 plates of each region 1928-1952; mainly blue.
- AC, AM, etc. - scale 600-700"/mm; 35 field; limiting magnitude 12
(some go fainter); several hundred plates of each region 1898-1954; mainly blue.
- AI, BI, FA - scale 1200"/mm; 50 field; (of limited use.)
- Damon (DN,DS) - scale 580"/mm; 35 field; limiting magnitude
14-15; 20-50 plates of each region 1965-1990; blue; a few
yellow and red of limited use.
- Series plates - filed chronologically (see card catalogs filed by
- Southern hemisphere:
A (limiting magnitude 17), MF, B, ADH, etc.; earliest plates
- Northern hemisphere:
MC (limiting magnitude 17), MA, I, IR, J, etc.; earliest plates
1890's (MC from 1909).
- Palomar sky survey (paper)
- European Southern Observatory "Quick Blue" survey (glass)
- Available equipment
- Blink microscope
- Variable iris photometer (good to 0.04 mag on large scale with many
grains per image)
- Polaroid copying camera (fixed 3x enlargements)