Information on Service 'HDAP Datalink'

This service lets you access cutouts from HDAP plates and retrieve scaled versions.

For a list of all services and tables belonging to this service's resource, see Information on resource 'HDAP -- Heidelberg Digitized Astronomical Plates'

Service Documentation

The scanning of the plate archive at Landessternwarte Heidelberg was initiated by Holger Mandel and Kurt Birkle in 2006 and was funded by the Klaus-Tschira-Foundation. Almost all usable direct plates in the archives are now scanned, and the funded phase of the project is over. Only minor additions are expected any more.


The plate archive consists of plates from many different sources. The following table gives an overview of the instruments at which the plates were taken:

plate letter name eff. focal length [mm] aperture ratio scale [as/mm] plate size latitude longitude height
A Calar Alto Schmidt telescope 2400 f/3 86 24x24cm 37.22417 N +2.5375 W 2168 m
B Königstuhl Bruce telescope 2000 f/5 103 24x30cm or 30x30cm 49.39861 N -8.72083 E 560 m
C 1.23m in Casseg. focus with corrector 9857 f/8 20.9 24x24cm 37.22361 N +2.5461 W 2138 m
D 72cm Walz- Reflektor 2815 f/3.9 73.3 13x18cm or 9x12cm 49.39861 N -8.72083 E 560 m
E 2.2m in Cassegrain focus with corrector 17037 f/7.744 12.1 20x25cm (8x10in) or 24x24 cm 37.22361 N +2.5461 W 2138 m
F 3.5m in primary focus with 3-lens corrector 13761 f/3.93 15 20x25cm (8x10in) 37.22361 N +2.5461 W 2138 m
F 3.5m in primary focus with 2-lens corrector 12195 f/3.48 16.9 12.5x20 (5x8in) 37.22361 N +2.5461 W 2138 m
H 2.2m MPG ESO/La Silla 17679 f/8 12 20x25cm -29.257225 S +70.734595 W 2335 m
G Wolf's Doppel- astrograph (15cm) on Königstuhl (7/1897-1909) 900mm f/6 230 13x18cm or 9x12cm +49.39861 N -8.72083 E 560m
G Wolf's Doppel- astrograph (15cm) in Märzgasse (1887-7/1897) 900mm f/6 230 13x18cm or 9x12cm +49.60988 N -8.69387 E 110m

Unfortunately, instrument data on the 2.2m MPG telescope on La Silla are lost. If anyone can help out, please contact

The Observation logs of the more ancient observations are available from UB Heidelberg.

More Information

The project was discussed on a poster shown at the 2007 meeting of the Astronomische Gesellschaft in Würzburg.

A slightly more technical article appeared in the proceedings of the 2014 Astroplate conference.


This is what the photographic plates these scans were prepared from look like --


The archive of plates from Wolf's eight-inch telescope --


The Bruce archive -- the rack's bend indicates the plates are kept beneath an observatory dome --


The scanner used by this project (Heidelberg Nexscan F4100; the resolution is 100 pixels per millimeter at 200 pixels per millimeter optical scanner resolution) --



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Input Fields

The following fields are available to provide input to the service (with some renderers, some of these fields may be unavailable):

NameTable Head DescriptionUnitUCD
ID Id The publisher DID of the dataset of interest N/A;meta.main
maxrec Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
responseformat Output Format File format requested for output. N/A meta.code.mime
verb Verbosity Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. N/A N/A

VOResource XML (that's something exclusively for VO nerds)