Lowell Observatory - Anderson Mesa Station

Latitude and longitude: 35°05′49″N 111°32′09″W (+35.0969, -111.5358)
Elevation: 2,163 meters (7,096 ft)
Site manager: Stephen Levine
Internet access:
Weather statistics:
Typical good seasons:


Wright 28 (W28) Donated by the late Paul Wright

Type:  Celestron C11 Schmidt-Cassegrain
Aperture: 280mm
Focal length: 1717mm
F-ratio:  6.13
Focuser:  Moonlite (www.focuser.com) motorized focuser, 2” diameter drawtube.


Pointing accuracy is  typically 1 – 2 arcminutes 'in the blind', but after a plate solve/reslew pointing error is reduced to 20 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:  Sara Beck

Typical seeing:  2.8 arc seconds FWHM
Best seeing:  2.0 arc seconds FWHM
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

Filter wheel:  SBIG CFW-10
Filters:  C B V R I  Ha  Sii  Red645NM  Sloan g'   Sloan r'
Exposure ratios/filter:  C=0.25  B=3.0  V=1.0  R=0.55  I=1.1  HA=14  Sii=15  Red645NM=13  Sloan g'=1.1  Sloan r' =0.55  (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:  765 x 510
Pixel scale:  1.08 arcsec/pixel
Field of view:  14 x 9 arc minutes
Gain: 2.5e-/ADU
Readnoise: 19e-
Full well:  Above 44,000 ADU response is not linear
Cosmetic defects:  None
Dark current: 1e-/sec/pix at 0C typical
Read time:  3 seconds
Shortest exposure:  0.11 sec
Compressed image size:  330KB

Typical images

Star Image Flat Bias Frame Dark Frame

Typical use of system 
Multi-filter 'snapshot' coverage once a night for many targets, or long time-series of a small number of targets, or a mixture of the two.

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).