[Aavso-photometry] SSP-4 photometer available for loan

[arne]

Jeff Hopkins wrote:
> Hi Arne,
> 
> I think it's great the AAVSO has SSP-4 units to lend. This is an 
> exciting area of photometer and before the SSP-4 was well out of reach 
> of most smaller observatories.
> 
> As you mentioned using the SSP-4 is very different from CCD photometry 
> and while somewhat similar even different from my single channel photon 
> counting. The software that comes with the unit is good once you get to 
> understand it. It does not reduce the data, only provides date, time and 
> counts.
> 
> The SSP-4 seems ideal for the epsilon Aurigae project as there are very 
> little data for the infrared during the eclipse. Continuous monitoring 
> out of and during the eclipse may show some most interesting data and 
> help decipher what they mysterious gigantic secondary object is.
> 
> When I purchased my SSP-4 I was determined to use it exclusively for 
> epsilon Aurigae. I tried it on my C-8 with very disappointing results. 
> While out-of-eclipse epsilon produced somewhat reasonable counts the 
> comparison star lambda Aurigae was about the same as the sky. I found 
> out later that Optec recommends at least a 10" scope.  I purchase a 12" 
> LX200 GPS to use with it. While the counts were much better, the signal 
> to noise was still not good for lambda. The system produce fair data, 
> but I was not happy with it. I tried it on a 16" LX200 and it was much 
> better. My recommendation for using the SSP-4 on the epsilon Aurigae 
> project is to use at least a 12" aperture with 14" or 16" or greater 
> preferable. Remember when epsilon goes into eclipse the counts will drop 
> dramatically.
> 
> Anyone wishing more information on the SSP-4 cans see 
> http://www.hposoft.com/Astro/IR.html
> 
> Anyone interested in the epsilon Aurigae campaign please drop me an e-mail.

Note that there will be an epsilon Aurigae campaign as part of IYA2009,
conducted by the AAVSO for Bob Stencil (with whom Jeff is working).

The NIR is quite different than optical photometry.  If lambda Aurigae,
the optical comparison, is too faint, then choose another compstar that
is better suited for NIR measures.  You do not have to stay locked into
the optical comparison star.  Epsilon Aurigae is J=1.9, H=1.7.  It dropped
about a magnitude visually during the 1983 eclipse, so it should still
be easy with a 10" telescope and the SSP-4.  Certainly more aperture
is always nice, but not essential.
Arne