MDM Observatory's 8K CCD array project:
OVERVIEW OF 8K CCD ON 1.3-METER e-mail: arlin@astro.columbia.edu Telephone: (212) 854-7899 |
The field-of-view of the 8K array on the 1.3-meter would be 44.5 arcmin with 0.32 arcsec/pixel, and can operate with the same corrector. In comparison, the unvignetted field on the telescope at least one degree across and image quality can be as good as 0.8 arcsec FWHM or better. There is some evidence, however, that the telescope suffers from a still poorly-understood flexure problem that effects imaging quality across the field.
Nominally, the 1.3-meter would require an additional 12.0mm spacer between the
telescope and instrument; however, the telescope has since been modified so as
to require the same back focus as the 2.4-meter.
The performance is calculated assuming the 1.3-meter is nearly RC, but this
needs to be confirmed given that the actual parameters for the optical
prescription have been lost.
With these assumptions the system will provide the following imaging quality.
Imaging Performance of Byard Corrector on 1.3-meter:
Field Angle | R.M.S. Diam. (U) | R.M.S. Diam. (B) | R.M.S. Diam. (V) | R.M.S. Diam. (R) | R.M.S. Diam. (I) |
(arcmin) | (arcsec) | (arcsec) | (arcsec) | (arcsec) | (arcsec) |
0 | 0.60 | 0.80 | 0.41 | 0.43 | 0.32 |
6 | 0.60 | 0.80 | 0.41 | 0.41 | 0.30 |
12 | 0.58 | 0.82 | 0.39 | 0.39 | 0.26 |
18 | 0.60 | 0.86 | 0.39 | 0.41 | 0.28 |
24 | 0.71 | 0.95 | 0.52 | 0.54 | 0.43 |
30 | 0.98 | 1.10 | 0.77 | 0.77 | 0.69 |
This performance corresponds to the corrector incorporating two Risley prisms (in an ADC) to cancel atmospheric dispersion.