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Photometry without CCD?

  1. Nov 16, 2015 #1
    CCDs are very cheap, but I was wondering if there was an even cheaper alternative to CCDs if the goal is differential photometry on magnitude 5 and under stars. The data only needs enough precision to prove/demonstrate the concept, and to develop a good sense of the workflow in doing photometry from observational data. Assume I have a 6" newtonian.

    Photomultiplier tubes such as the 1p21 can be found for less than 40$, but require expensive 1000V power supplies.

    I am more curious about single photodiodes, or even more crude ways of collecting starlight such as photoresistors. Just wondering if anyone has experimented with some off the beaten path electronic detectors.
  2. jcsd
  3. Nov 17, 2015 #2


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    I would suggest that their sensitivities would be way too low for the faintness of starlight
  4. Nov 17, 2015 #3
    A photoresistor could not even detect something like Vega? Just curious, not sure how to calculate something like that using a datasheet.

    I was thinking photodiodes at least had been in use a few decades ago.
  5. Nov 19, 2015 #4
    It is much simpler to do differential photometry with an area detector where the target and comparison star can be on the same image. You can use a DSLR or even a point and shoot camea if it can do long exposures.
    Regards Andrew
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