| plate | date |  | emulsion/filter/exposure |
| U9362 | 84:06:03 | 12:27,13:30 | IIIaJ/UG1/3 hr. |
| J4882 | 79:03:23 | 12:25,13:20 | IIIaJ/GG395/1 hr. |
| J9229 | 84:04:26 | 12:27,13:30 | IIIaJ/GG395/1 hr. |
| R2936 | 77:02:27 | 12:25,13:20 | IIIaF/RG630/48 min. |
|
|
the equatorial coordinates of the plate centres:
in hours and minutes of time for right ascension (
) and in degrees
and minutes of arc for declination (
).
The VPC is based on four photographic plates (one U, two 
and one
) of the same field; all of which were exposed on the 1.2-metre UK
Schmidt Telescope (UKST) at Siding Spring Observatory in Australia.
Details of all four plates are listed in Table 1 (click here). Each plate
measured 356 mm square and covered an area of the sky 
by
within an imaging area of dimensions 343 mm by 343 mm.
The plate scale was therefore 67.12 arcsec/mm in each case.
All of the plates were hypersensitised by successive soaking in
nitrogen and hydrogen gas. Those plates taken after 1982 December 3
had the added advantage of being nitrogen flushed;
that is exposed under a constant stream of nitrogen. The significance
of this flushing process is dealt with in Sects. 3.7 (click here) and 6.2 (click here).