Three of our telescopes at RASO/Mayhill are equipped with BVRI photometric filters and capable of all-sky photometry (GRAS 001, 002, and 002). If you wish to try all-sky work, please contact Ed Wiley. GRAS 008 in Australia and GRAS 007 in Israel are equipped with photometric V-filters and thus can be used for variable star work.
Several members at RASO are working with the Mayhill telescopes to calibrate the systems for photometry.
May 2007 CCD tests for G001, 002, and 004 (aka AREO 1,2, and 4) are completed.
G001. gain = 3.27 e-/ADU; Noise = 12.96 e-r.m.s; dark current = 2.81 e-/pixel/sec
G002. gain = 2.56 e-/ADU; Noise = 16.29 e-r.m.s; dark current = 0.42 e-/pixel/sec
G004. gain = 2.48 e-/ADU; Noise = 17.50 e-r.m.s; dark current = 1.12 e-/pixel/sec
UBVRI filter transmission specification can be downloaded as a PDF from Optec.
Chris Norris reports (PDF file) photometry results for M67 and NGC 7790 using AREO2. He has found that the new focus capability has significantly increased his ability to measure faint variables.
Martin Nicholson has posted a web page outlining how observers can get into measuring and reporting variable stars.
Chris Norris has completed CCD tests for AREO 1, 2, and 4. Results can be downloaded as a PDF and are excellent, image with confidence!
Geir Klingenberg has posted a study of transformation coefficients for AREO1.