(NB - the column numbers given below do not necessarily match the output given by UKSCAT (the telnet and www interface to search the log) as extra spaces have been added to make it easier to read. However the parameters do appear in the same order.)
Columns 1- 2 Plate prefix 3- 7 Plate number 8 Plate suffix 9-11 Survey code (if relevant) 12-15 Non-survey code (T number) 16-20 Field number or other identification 21-25 RA (hhmmt) (t is tenth of a minute, e.g 7105 = 07h 10m 30s) 26-30 Dec (+/-ddmm) 31-36 Date of exposure (yymmdd) 37-40 LST of start of exposure (hhmm) 41-46 Emulsion 47-52 Filter 53-56 Exposure time (mmmt) (t is tenth of a minute, eg 700 = 70 minutes) 57-61 Plate grade 62-64 Prism code (for prism plates only)
Plate Prefix (Cols 1-2)
A one- or two-character code for the filter/emulsion combination. The two- letter codes are interpreted as follows:
First Letter Filter Second Letter Emulsion
U None or - -
WG 305
B GG 385 B IIA-O
J GG 395 J IIIa-J
Y GG 455 - -
V GG 495 V IIa-D
O OG 590 - -
R RG 630 R IIIa- F, 4415 OR 098
I RG 715 I IV-N
W RG 830 - -
Z RG1000 Z IZ
Certain standard filter/emulsion combinations have been contracted to
a single letter code:
U IIa-O or IIIa-J ...emulsion with... UGI ...filter
B IIa-O GG 385
J IIIa-J GG 395
V IIa-D GG 495
R IIIa-F, 4415 or 098 RG 630
I IV-N RG 715
Z IZ RG1000
Plate Number (Cols 3-7)
A running number for all UKST plates.
Plate Suffix (Col 8)
P indicates a full aperture prism was fitted (see also cols. 62-64)S indicates a sub-beam (Pickering) prism was fitted.
G indicates an objective grating was fitted.
M indicates multiple images.
T indicates the exposure was tracked eg for a comet. Only the target image will be stationary other images will be trailed.
Survey Code (Cols 9-11)
An entry here indicates that the plate was taken for one of the UKST Sky Surveys.
J - Deep IIIa-J survey (ESO/SERC survey), Dec -20 to -90
I - Deep IV-N survey (Southern Declinations)
SR - Short red survey (comparison to I survey)
R - Deep red survey, declination -20 to -90
EJ - Deep IIIa-J survey, declination -20 to 0
ER - Deep IIIa-F survey, declination -20 to 0
P - Objective prism survey
Non-Survey Code (Cols 12-15)
Non-survey code number (T number) - if plate taken for non-survey programme.
Field Number or Object Name (Cols 16-20)
Field number is the ESO/SERC Survey field number.
RA and Dec (Cols 21-30)
Equinox 1950 coordinates of the plate centre.
Date (Cols 31-36)
UT date of exposure.
LST (Cols 37-40)
Local Sidereal Time of start of exposure.
Emulsion (Cols 41-46)
Expanded details of prefix data;
Filter (Cols 47-52)
Expanded details of prefix data; data on special filters
Prefix Filter Size Details
Col
O2 AAO372 130mm sq Interference filter centred on 3727A ([OII])
HG AAO434 130mm sq " 4340A (H gamma)
IF AAO460 130mm sq " 4600A
HE AAO468 130mm sq " 4686A (HeII)
IF AAO486 130mm sq " 4860A (H beta)
O3 AAO500 130mm sq " 5007A ([OIII])
IF AAO540 130mm sq " 5400A
IF AAO562 180mm sq " 5620A
HE AAO587 130mm sq " 5870A (HeI)
O1 AAO630 130mm sq " 6300A ([O1])
IF AAO643 130mm sq " 6430A
S2 AAO672 130mm sq " 6725A ([SII])
HA AA0656 250mm sq " 6567A (H alpha)
IF MB 675 200mm sq " 6751A
IF MB 569 200mm sq " 5696A
IF MB 666 200mm sq " 6668A
HA MB 657 300mm Mosaic " 6567A (H alpha)
HA RG630H 400mm Mosaic " 6567A (H alpha)
IF MB 486 200mm sq " 4861A (H beta)
IF HZ 580 21cm circ " 5800A
IF HZ 600 21cm circ " 6000A
IF HZ 620 21cm circ " 6200A
IF HZ 640 21cm circ " 6400A
IF HZ 660 21cm circ " 6600A
X HZUBLK 21cm circ UV-Blocker
X VLZ520 150mm sq Waveband (1/2 power): 25nm at 520nm
X VLX400 150mm sq Waveband (1/2 power): 45nm at 400nm
P HN 32 Linear polarisation
P HN 38 Linear polarisation
LP HNCP37 Left-handed circular polarisation
RP HNCP37 Right-handed circular polarisation
Exposure Time (Cols 53-56)
Exposure time in tenths of a minute.
Quality Control Plate Grade (Cols 57-61)
All plates are quality controlled and assigned a grade. The first letter of the grade (usually A,B,C) indicates the overall quality of the plate. The subsequent letters indicate specific defects as follows:
I - Denotes image size larger than 40 microns
T - Denotes detectable image elongation on most images
U - Denotes underexposure (relative to exposure time)
E - Denotes emulsion blemish(es)
P - Denotes processing marks
F - Denotes fogged plate or high chemical fog
D - Denotes overexposed plate (high central density)
S - Denotes marks caused by electrostatic discharge
H - Denotes haze haloes
M - Denotes multiple images (often caused by poor
guiding in cloudy conditions)
X - Denotes any blemish not listed above
Survey plates are normally also given a grade number; the lower the number the better the plate quality. An 'A' grade plate scores 3 or lower.
Prism Code (Cols 62-64)
This is a three-character code giving information on the prism(s) used.
(I) Shows prism dispersion
1 - dispersion of 2440A at H gamma (44' prism alone)
2 - dispersion of 1260A at H gamma (prisms in anti-parallel)
3 - dispersion of 830A at H gamma (2 1/4 degree prism alone)
4 - dispersion of 620A at H gamma (prisms in parallel)
(II) Shows prism orientation
N - prism apex north (180 deg) (spectra north-south)
E - prism apex east (270 deg) (spectra east-west)
S - prism apex south (0 deg) (spectra south-north)
W - prism apex west (90 deg) (spectra west-east)
(III) Shows if spectra widened or not
W - indicates spectra widened
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