[Aavso-photometry] Start up question

[Jeff Hopkins]

Hello Don,

It is certainly possible to do this. You will be limited to fairly 
bright stars, however, unless you are using a meter class telescope. 
To be useful you will need to invest in photometric filters and 
probably a filter wheel. Then you should calibrate your system. Once 
done you  will have a good system capable of producing valuable data.

Good  luck.

Jeff

At 13:04 -0700 05/31/2007, Rumrill, Donald M \(US SSA\) wrote:
>Hello all,
>
>I am a fairly recently started amateur "star gazer," though I've paid
>close attention to astronomy for many years.  I am thinking, that to
>give myself a little more focus than just gawking around the heavens,
>that I would look into photometry for a sense of purpose and perhaps a
>little contribution to the avocation.  Many years ago, I designed a star
>simulator with a detector at the system's output as part of a feedback
>control to set and maintain the simulated star's magnitude.  I used a
>photodiode and boxcar integration to achieve this, with light levels
>down in the 10's of photons.  Based on this experience, my thoughts were
>to build something similar to attach to my telescope and make
>measurements; similar to the photometers described in AASVO's on-line
>literature.  My question is this:  Given the state of art ofCCD cameras,
>is it worth my while to build a photometer, or would I be better off
>saving my pennies and purchasing a CCD camera system?  I could probably
>build a photometer for around $100 given my contacts within the
>electronics industry.  I haven't done an error budget yet, but expect to
>be well under 0.1%.
>
>Don R.

-- 
Jeff Hopkins
HPO SOFT
Counting Photons
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