The High-Speed UBVRI Photometer MCCP
Das MCCP am 0.8m Teleskop auf dem Wendelstein.
For precise multicolour aperture photometry of fast variable phenomena
the Multi-Channel Multi-Colour Photometer
MCCP has been developed.
This instrument uses three optical fibers which are positioned by
computer control onto three light sources
(e.g. the variable star, a nearby comparison and the sky background)
in the focal plane of the telescope.
The fiber ends repectively form the entrance slits of three
prism-spectrographs.
The individual spectra are projected on fiber bundels which allow to
select 5 overlapping broad band regions corresponding to the
Kron-Cousins UBVRI colours.
The colour channels of each lightsource feed 5 photon counting
photomultipliers which are thermoelectrically cooled to -20 degree
Celsius.
The output signals are recorded by a real time multi-tasking VME-Bus
computer system.
This measuring method yields simultaneous UBVRI data of three light
sources with a maximum time resolution of 1 ms.
Peripheric devices include an on-line graphics system which allows to
monitor selected light curves and an autoguider system which controls
the star centering in the fiber diaphragms.
Schematic drawing of th MCCP
Specifications of the MCCP:
| Simultaneous measuring channels: | 3 |
| Diameter of measuring diaphragms: | 0.6/0.8/1.0 mm |
| Simultaneous colour channels: | 3 x UBVRI |
| Detectors: | 15 HAMAMATSU Photomultipliers |
| Time resolution: | <= 1 ms |
| Max. count rate per channel: | <= 2 10E5 cts/s |
| Typical dark count rates: | <= 5 cts/s |
| Spectral range: | 350 - 900 nm |
| App. brightness range: | V = 8...15 mag.( at 80cm telescope) |
For further details see:
Barwig,H., Schoembs,R., Buckenmeyer,C., 1987:
"A multi-channel multi-colour photometer for high time resolution",
Astron. Astrophys., 175, 327.
Mantel,K.H., Barwig,H., 1994:
"Multichannel-Multicolour Photometry - experiences from a long term
observing campaign",
in Proc. of the NATO Advanced Research Workshop on "The Impact of
Long-Term Monitoring on Variable Star Research", November 1993, Ghent,
Belgien, NATO ASI series C436, eds. C.Sterken, J.de Groot, 329.
Barwig,H., Mantel,K.H., Kiesewetter,S., 1998:
"Impact of Fiber Optics on Photometry - Design of two High-Speed
Multichannel Instruments", in Proc. of the meeting held in Puerto
de la Cruz, Canary Islands, Spain, 2-4 December 1997 on
"Fiber Optics in Astronomy III", eds. S.Arribas, E.Mediavilla,
F.Watson, Astronomical Society of the Pacific, Conference Series, Vol.
152, 320.
Last revision: July 2001
email: Heinz Barwig (hbarwig@usm.uni-muenchen.de)