WIYN Facts

A collection of technical information about the WIYN telescope and facility

As Built Optical Prescriptions

 

Wide field corrector  (MOS port)
Eff. Focal Len.	21980.8
Total Track	6902.25
Image Space f/#	6.28024
Exit Pupil Dia.	1177.87
Exit Pupil Pos.	-7399.59
Back Focal Dis.	2699.01
Plate scale (on axis)	9.384 arc-sec per mm
Plate scale (63% field R)	9.408 arc-sec per mm
Distortion	0.635%  (0.5 degrees off axis)
Magnification	3.5877
Field of View	1 degree
Wavelength coverage	0.49 to 1.1 microns
Lens Units	Millimeters

Surf Radius	Thickness	Glass	Diameter	Conic
STOP 2 3 Infinity 4 Infinity 5 6 7 8 9 Infinity 10 Infinity IMA	-12253.5 4203.239 -475.4 2267.51 20 1 20 0 865.9 0 0	MIRROR MIRROR   SILICA SILICA	3498.85 1118.326 693.5089 748.2776 484.655 482.0019 476.3526 466.5941 472.1198 386.6157 385.9148	-1.0708 -3.74 0 0 0 0 0 0 0 0 0

Autocad cross section of the two element corrector.

Notes: The corrector consists of two fused silica lenses with all spherical surfaces in an elastomeric mounting to a PH-17 stainless steel cell.
Lens diameter	500 mm (19.685")
Cell diameter	543.8 mm (21.41")
Wavefront quality	0.074 waves rms 0.38 waves P-V

This is the full aperture wavefront quality, however the wavefront to any one image is much smaller, hence the wavefront error contribution is negligible.
 

Modified Cass Port (an axi-symmetric focus for polarimetry)
Eff. Focal Len.	47810.86 mm
Image Space F/#	13.665
Exit Pupil Dia.	88.9 mm
Exit Pupil Pos.	-1227 mm
Back Focal Dis.	485.417 mm
Plate Scale  (on axis)	4.314arc-sec per mm
Magnification	2.173        f(13.7)/f(6.3)
Field of View	10 arc minutes (approx. diam.)
Radius of Focal plane	-190.64 mm
Wavelength coverage	panchromatic

Surf Radius	Thickness	Glass	Diameter	Conic
-2000 -354.85 -190.64	0.00 -517.44 1002.84	MIRROR MIRROR	359.0 100.0 130.0	-3.799155 (-e2) -1.44617 0

Autocad cross section of the two element f/6.3 to f/13.665 reimager.
 

Notes:

The reimager provides a four-reflection focus at higher magnification with low polarization optics (ie no 45 degree fold mirror). The f/13.665 focus is equipped with an instrument rotator and can support an instrument up to 200 lbs. The floor-to-focus clearance is approximately one meter.
 

Notes:

ADC lens is mounted on a slide for remotely controllable deployment or removal from the beam. The two lenses are mounted on rotating stage with 0.1 degree step resolution.
 
 

Active optics Lateral actuators         24 passive axial actuators            66 passive - active Active force range       1110 Nt (250 lb) push                                   to 876 Nt (197 lb) pull Correction modes       Astigmatism, trefoil

Francois Roddier inspects the active optics hardware on theback of the primary mirror cell.

Delivered Image Quality best FWHM measured           0.43 arc-sec Median FWHM (72 samples) 0.7 arc-sec Typical profile      80% ee                            1.89 x FWHM      90% ee                            2.45 x FWHM

Images taken with the WIYN telescope.

Telescope
Total moving weight	33,060 Kg (72,740 lb)
Elevation axis weight	16,170 Kg (35,580 lb)
Component weights fixed:
Az square frame	7440 lb
Az bearing	350
Az brg pedestal	1938
Sole plate	1510
Fixed Total	11,238
amzuith:
Cone	11,160
Fork	21,000
El Pillow blocks (2)	5000
Nasmyth instruments (2)	3000
Az Total:	37,160
elevation:
Cass instrument	400
Center section	8950
Motor c'weights (2)	880
elevation sectors (2)	1240
Main truss	2576
Head frame	1057
Felxion bars (4)	696
Primary cell	11,039
Primary Mirror	4321
Tertiary pedestal	450
Secondary cell	279
Secondary mirror	263
Secondary actuators	133
Secondary cage & spider	955
Secondary baffle	30
Tertiary assembly	552
Cell fixed weights	400
Mirror cover	425
PM cell trim weights	1282
El Total:	35,578
MOI elevation axis	6.4 E5 in-lb-sec2
MOI azimuth axis	1.16 E6 in-lb-sec2
Swing radius	5370mm (211.44")
Height to el axis	2517.8mm (99.125")

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