One of the principal devices used in observations at the telescope Zeiss-1000 is a CCD photometer. This device was put into operation in March 1994. 46% of the observational programs of the second half of this year were fulfilled using this equipment.
The photometer was built using the standard set of astronomical image recording system based on a CCD of 530 X 580 pixels. The photometer incorporates: automatic remote control; a set of 8 filters; fast shutter that allows short exposures up to milliseconds; internal standard light sources forming a "flat field".
The system of data acquisition is realized in two versions:
The field of view of the photometer is 143 X 212". The scale in the field without the reducer is 15.27"/mm, the element size is 0.275 X 0.366".
The photometer has 5 wide-band and 3 narrow-band filters. The wide-band filters in combination with a CCD of type K585 realize the system similar to the Cousins one.
The central wavelengths of the narrow-band interference filters are designed for the lines [OIII] 5007, H 6563, [SII] 6734 when working in a parallel beam, all the filters have a width at a half of maximum of about 85 .
The count rates (electron per second) for ADU = 1e- computed
image for U = B = R = I = 20.0 for an object observed at air mass
equal to 1.0 with the given version of CCD at the telescope Zeiss-1000 are
presented in Table 1.
|Count rate (e-/s)||0.18||10.8||12.4||15.7||6.0|
|Flux at the upper boundary of the atmosphere, (ph/s)||30||120||75||66||38|
|Extinction coefficient, (magnitude/air mass)||0.62||0.32||0.18||0.11||0.07|
|Quantum efficiency CCD+filters+telescope, (%)||1.1||12.0||19.4||26.4||16.9|
|Zero point, A0 V, zenith e-/ADU = 1, (magnitude)||18.14||22.58||22.73||22.99||21.95|