The Plate Catalogue

Our plate catalogue can be downloaded.
ukst_catalogue (plate number order) and
ukst_ra_catalogue (ordered in Right Acension)

The catalogue of existing UKST plates can be SEARCHED

The UKST Plate Catalogue is stored one plate to a record as follows:

(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.)


 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
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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