CCD Detectors at MDM


MDM Observatory has six CCDs available for general use.  These CCDs
can be used in imaging mode at either telescope, and on the Modular and
MkIII spectrographs.  The 8K Mosaic camera and the OSU CCD spectrograph
have their own CCDS and the user is referred to the appropriate 
documentation.

CCD name	format		pixel size	

Charlotte	1024x1024	24 micron	thinned, backside ill.
						manufacturer: SITE

Templeton	1024x1024	24 micron	thinned, backside ill.
						manufacturer: SITE

Echelle		2048x2048	24 micron	thinned, backside ill.
						manufacturer: SITE

Nellie		2048x2048	21 micron	thick, frontside
						manufacturer: STIS

Wilbur		2048x2048	15 micron	thick, frontside
						manufacturer: LORAL

Lurvy		512x1024	24 micron	thick, frontside 
						manufacturer: Lincoln Labs

Templeton and Echelle have the best response overall, and are the ones
to use in the ultraviolet.  Nellie and Wilbur have limited response at
Johnson B, and have a higher cosmic ray rate than the thinned devices.

QE curves are available for Charlotte and Echelle.

Readout times are typically 30 -> 31 seconds for the 1024x1024 devices
(unbinned).  Wilbur and Nellie take approximately 100 seconds when read
out in the full 2048x2048 format, and the Echelle takes 120 seconds
when read in the full 2048x2048 format.  All devices are read through a
single amplifier.

All CCDs produce 16 bit unsigned data: 0-65,535 DN.  Nominal values
for gain and readnoise as determined during the fall of 1995 are:

CCD name	gain (e/DN)	readnoise (e rms)

Charlotte	3.16		5.45

Templeton	3.47		5.33	(determined Oct 1996)

Echelle		1.3/2.7		7.9	(determined April 1997)

Nellie		2.94		4.38

Wilbur		2.25		4.73	

Lurvy		1.33		6.05	(determined December 1996)


The following table gives the angular size ("/pixel) and the field of
view (arc-minutes) for these CCDs when used in direct imaging at the
various foci of the MDM telescopes.  These are computed using the scale
factors given in the telescope manuals.  They are not measured values.

			2.4m Hiltner telescope

		f/7.5	11.528"/mm	f/13.5 	6.399"/mm

Charlotte	0.28	4.72		0.15	2.62

Templeton	0.28	4.72		0.15	2.62

Echelle		0.28	9.44		0.15	5.24

Nellie		0.24	8.26		0.13	4.59

Wilbur		0.17	5.90		0.10	3.28

Lurvy		0.28	2.36 EW x
			 4.72 NS
			 at pa=0.0


			1.3m McGraw-Hill telescope

		f/7.6	20.72"/mm	f/13.5 11.81"/mm

Charlotte	0.50	8.49		0.28	4.84

Templeton	0.50	8.49		0.28	4.84

Echelle		0.50	16.98		0.28	9.68

Nellie		0.44	14.85		0.25	8.47

Wilbur		0.31	10.61		0.18	6.05






MDM Home | Technical Information | Manuals | Weather
Schedule (mirror) | Observing Prep Form | Contact Info | Rules | Lodging & Transport Info

Astronomy at:
Michigan | Dartmouth | Ohio State | Columbia |

Ohio Univ.


This page last updated: May 9, 2005.