Telescopes at Millikin

Parallax Instruments 20" Ritchey-Chrétien

Model No. PI500R, 20"
Clear Aperture 508mm
Focal Ratio F/8.1
Focal Length 4114mm
Primary & Secondary Mirror
Zero Expansion Astrositall
Telescope Tube Low Expansion Carbon
Secondary Amplification 2.70X
Spacing (Approx.) 40"
Mirror Coatings AlSiO
Optical Tube Dia. 24"
Optical Tube Length 56"
Optical Tube Weight 130lbs.
Focuser 2.7"
Finder Scope 7X50
Tube Rings Standard
Primary Cooling Fan Standard (Quantity 3)
Slewing Handle Standard
Tube C'wt Bar Assy. Standard (Quantity 2)



 Meade LX 200 8" Schmidt-Cassegrain

 f 6.3  10 
Focal Length 1280mm 2000mm
Aperture 203mm 203mm
Secondary 88mm 76mm
Obstruction 43% 37%


Drive Fully computer controlled; 64359
object library; automatic GO TO
Altaz Yes
Polar Yes with optional wedge
Eyepiece 26mm Plossl
Finder 8x50
RS232 Yes
Power 18v DC (AC adapter included)
Weight 41lbs 41lbs
Tripod Standard



Cameras at Millikin



CCD Kodak KAF-0402ME + TI TC-237
Pixel Array 765 x 510 pixels, 6.9 x 4.6 mm
Total Pixels 390,000
Pixel Size 9 x 9 microns
Full Well Capactiy (ABG) ~50,000 e-
Full Well Capactiy (NABG) ~100,000 e-
Dark Current 1e-/pixel/sec at 0C
Antiblooming KAF-0402ME is NABG only ABG optional
Shutter Electromechanical
Exposure 0.11 to 36000 seconds, 10ms resolution
Correlated Double Sampling Yes
A/D Converter 16 bits
A/D Gain 2.6e-/ADU
Read Noise 15e-RMS
Binning Modes 1 x 1, 2 x 2, 3 x 3
Pixel Digitization
Up to 420,000 pixels per second
Full Frame
~35 seconds
Field of View 12 x 8 arcminutes on f/10 Meade LX 200
Pixel Size .9 x .9 arcseconds on f/10 Meade LX 200
Limiting Magnitude Magnitude 14 in 1 second
(for 3 arcsec FWHM stars) Magnitude 18 in 1 minute
Cooling - standard Single Stage Thermoelectric, Active Fan,
Water Assist Ready -45 C from Ambient
Temperature Regulation +-0.1 C
Power 5 VDC at 1.5 amps, +-12 VDC at 0.5 amp
desktop power supply included
Computer Interface Parallel
Windows 98/2000/Me/NT/XP
Guiding Dual CCD Self-Guiding




Imaging CCD  Kodak Enhanced KAF-1001E
Pixel Array 1024 x 1024 pixels, 24.6 x 24.6 mm
Total Pixels 1.0 million
Pixel Size 24 x 24 microns
Full Well Capacity
200,000 e-
Dark Curent 9 e-/pixel/second at 0 degrees C
Antiblooming NAGB only
Shutter Electromechanical
Exposure 0.12 to 3600 seconds, 10 ms resolution
Correlated Double
A/D Converter 16 bits
A/D Gain 2.0e-/ADU
Read Noise 14.8e-RMS
Binning Modes 1 x 1, 2 x 2, 3 x 3
Full Frame
40.8 seconds
Cooling - standard Two-Stage Thermoelectric, Water Assist, -40
C from Ambient Typical
Temperature Regulation +-0.1 degrees C
Power 10-18VDC, 12VDC nominal, Universal AC to
12VDC desktop supply
Computer Interface Parallel
Computer Compatibility Windows 98/NT/2000/Me/XP/Mac OS-X
Guiding Dual CCD Self-Guiding Standard,


SGS-Self Guided Spectrograph

Two gratings available, on a carousel for rapid selction
150 lines per mm (4.3 Angstroms per pixel)
600 lines per mm (1.0 Angstroms per pixel)
Slit Width 100 microns wide Entrance Slit
Accptance cone
F/6.3 by F/10
Narrow slit & 600
2.4 Angstroms
Narrow slit & 150
10 Angstroms
Wide slit & 600
10 Angstroms
Wide slit & 150
38 Angstroms
Relative Sensitivity to Diffuse Sources:  
Narrow slit & 600 lines/mm 1.0
Narrow slit & 150 lines/mm 4.0
Wide slit & 600 lines/mm 4.0
Wide slit & 150/mm 16.0
Dispersion: 1.07 or 4.3 Angstroms per pixel
Resolution Emission line is recorded with 2.4, 10 or 38 Angstroms Full Width at Half Maximum
Spectral coverage
per frame
About 750 Angstroms with the high resolution
grating, or 32000 with the low
resolution grating
Calibrated Micrometer Adjustment
3800 to 7500 Angstroms
Sensitivity Signal to noise ration of 10:1 for a 9th mag star, 20 minute exposure using a non-AGB ST-7 and a 10 inch (25 cm) apertaur in high resolution mode. An ABG ST-7 will reach magnitude 8. The low resolution mode will be 1.5 magnitudes more sensitive.
Entrance Slit 18 micron (2.3 arcseconds wide with 63 inch focal length telescope or 72 microns
Uses: Stellar Classification
Analysis of Nebular Lines
Indentification of spectroscopic binaries
Measurement of Stellar proper motion to +/-
km/sec accuracy
Measurement of Emission Nebula Proper Motions
Spectra of Laboratory and field sources