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Sutter Creek Observatory

Site
Latitude and longitude: 38°22'47"N 120°46'31"W (+38.3796, -120.7751)
Elevation: 529m
Site manager: Bill Goff
Internet access:
Weather statistics:
Typical good seasons:

Wright 30 (W30) - Donated by the late Paul Wright

Telescope
Type:  12-inch Meade LX-200 (Classic)
Aperture: 305mm
Focal length: 3050mm
F-ratio: 10
Focuser: Optec TCF-S

Mount
Meade LX-200 (Classic) fork
Pointing accuracy :  Typically 2 – 4 arcminutes 'in the blind', but after a plate solve/reslew pointing error is reduced to 40 arc seconds or less. Maximum unguided tracking restrictions, if any:  60 seconds
Computer:  PC/Win XP
Software:  Maxim for CCD/filter wheel control.  TheSky6Pro/TPoint for scope control and pointing model.  FocusMax for focuser control.  ACP and ACP Scheduler for overall system operation.
Telecope Advocate: Elizabeth Waagen

Imaging 
Typical seeing:  Note.  Images are intentionally defocused with the goal of FWHM 2.2 pixel radius.  At best focus this scope delivers undersampled images.
Best seeing:
Vignetting:
Scattered light:   After flat fielding, photometric errors are at the 1 – 2% level across the entire field.  (Arne has verified this with raster scan multi-image tests.)
Image defects:  None

Camera
Type: SBIG STL-1001E
Filter wheel:  SBIG 8-position
Filters:  BVRIg'r'i'z'  (Astrodon 3mm thick interference filters)
Exposure ratios/filter:  C=0.25   B=3.0   V=1.0   R=0.55   I=1.1  (Note – if your target is a very red star, expect to shorten R and I exposures and lengthen B exposures...assuming V exposures remain constant.)
Pixel count:  1024x1024
Pixel scale:  1.65 arcsec/pixel
Field of view:  28 x 28 arc minutes
Gain: 2.5e-/ADU
Readnoise:  
Full well:  Above 55,000 ADU the response is no longer linear.
Cosmetic defects:  None
Dark current:
Read time:  3 seconds
Shortest exposure:  0.11 sec.
Compressed image size:  420KB

Typical images

Star Image Flat Bias Frame Dark Frame


Typical use of system 
 
Mostly long time-series, with multi-filter 'snapshot' coverage filling in the rest of the night.

Miscellaneous notes 
Calibrated images are 16-bit, but can have negative values, and non-integer values.  You may have to set up your photometry software to specifically deal with this situation (some software deals with it automatically, some does not).

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484