[AAVSO-DIS] Looking for more and questions

[arne]

Chris Sauer wrote:
> 
> the manual mentions that one doesn't need a very large telescope however,
> I'm left wondering if my 5" is up to the task due to the lower light
> gathering capability when compared to the 12".  So, focal reducers and
> binning not withstanding, can I successfully take measurements with less
> than 1"/pixel or am I asking for trouble?
 >
There are many groups using small telescopes.  ROTSE-I, LOTIS, ASAS,
TASS are good survey examples; Richard Miles uses small refractors for
much of his work.  The problem is that you are limited to bright stars
(not all bad), and finding comparison stars in your CCD field of view
can be difficult.  For example, down to 9th magnitude, there are about
5 stars per square degree on average.  The surveys use large CCDs covering
large fields of view; TASS, for example, is 4x4degrees.  However, this
is a general restriction.  Even for bright stars, there are many variables
with nearby comparison stars; you just have to restrict your observations
to that subset if you have a small field of view.  An example is the
double-mode cepheid EW Sct, which has a bright comparison star only
three arcmin distant.  One purchase that is almost mandatory, though,
is a standard Johnson V filter, available from every camera vendor and
sites like http://www.astrovid.com

> 2)	Lastly, how does one get started with the AAVSO?  Do I need to
> become a member to actively participate?  Also, is there anyone in the
> Lehigh Valley that can help me get started with photometry should I need
> assistance.
> 
As Justin mentioned, you do *not* have to become a member to participate;
we welcome all observers.  On the other hand, we hope you feel that you
are getting benefit from our organization and will support it by becoming
a member when you are able.  For CCD tutoring, I recommend joining
our companion maillist:
http://www.aavso.org/mailman/listinfo/aavso-photometry
and asking questions!
Arne
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Arne A. Henden, Director                      ph:    (617) 354-0484
Amer. Assc. Var. Star Obs. (AAVSO)            fax:   (617) 354-0665
25 Birch Street                               email: arne at aavso.org
Cambridge, MA 02138 USA                       www: http://www.aavso.org
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