The guider at the Cassegrain focus of the 2.1-m telescope has been modified during Summer Shutdown 1999 to increase the field-of-view to permit imaging with a 2K2 CCD. Previously, the field-of-view was restricted to ~ 6' by the guider pick-off mirror and a detector larger than 1K2 would have been vignetted. Beginning in Semester 1999B T2KA will be available at the 2.1-m to allow a field ~ 10' on a side ( ~ 14' diagonal).
The 2K × 2K Tektronix CCD T2KA, which is no longer to be used at the 0.9-m telescope, will be the imaging device in the visible at the 2.1-m, starting in Semester 2000A. With 0.3" pixels, it will cover a 10' field, which should include all of the useable area. The modifications being made to the guider/adapter are expected to make the entire field free from vignetting.
A run to test and characterize the performance of T2KA at the 2.1-m Cassegrain focus is scheduled in late August, following completion of the modifications to the guider/adapter. We shall report on image quality, PSF variation and geometrical properties of the image over the full area when the results from this test are obtained. Look for this report via the KPNO page (www.kpno.edu) in early September.
Abi Saha