The DLR-MKIII CCD is the workhorse instrument at the 1.23-m telescope Cassegrain focus.
In a nutshell
|Instrument name||CCD DLR-MKIII|
|Observing technique||Direct imaging camera for (fast, efficient and accurate) photometry
|Shutter||Fast (Bonn-type): accuracy <1% with 0.1 s exposures|
|Wavelength range||330 nm to 890 nm (QE > 50%)
|Filters||100 mm: Johnson BVRI, FTmask, GG495, luminance LRGB+Halpha. Any 50 mm.|
|Detector size||4096x4096 pixels|
|Pixel size||15 μm = 0.314" on the sky|
|Field of view
21.4x21.4 arcmin with 100 mm filters (or ∅11' circular unvignetted with 50 mm)
<1 min full frame, <15 s binning 2x2. Parallel readout possible and frame transfer mask available.
On loan from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt e.V.), the DLRMkIII CCD is a fast read-out camera with a high-QE 4k CCD, offering a field of view over 21'x21', for 100 mm round filters. Using 50 mm filters limits the unvignetted field to ca. ∅11'. A filter wheel with 4 filters of 100 mm (frame-transfert mask available) or another one with 8 filters of 50 mm (see complete filter list here) can be mounted.
Since the 1.23-m telecope can be used remotely (based on the rts2 control system), observing runs with the DLR MK-III may be performed from the distance by experienced observers, having a stable internet connection and a casual Windows OS PC. They can control both the telescope, filter wheel, autoguider camera and DLR CCD itself (thru a basic GUI, or extensive scripting). Limited technical support on-site is available in remote mode, night and day, on a best effort basis.
At the moment, the 1.23-m telescope is only offered on a pay-per-night basis to interested groups. They must submit an observing proposal every semester. that will be evaluated by an external TAC. If accepted by this TAC, a MoU has to be signed with the CAHA direction before being authorized to use the 1.23 after finding the best compromise with the other users in terms of scheduling observing runs. See the 1.23 timeline here (right columns).
The DLR camera has been extensively used on the 1.23 since 2013. Before that, the 2k SITe#2b CCD was used. For reference, see the old observing manual (nowadays partly obsolete) of the former CCD, used until 2012.