[Aavso-photometry] Re: Ensemble photometry question (Robert J. Modic)

[Chuck Pullen]

I've just been using one standard deviation for the mean of the  
values given by the various comp stars.  In effect, you are weighing  
something n times, assuming random errors with each weighting.  Of  
course, Arne is the authority on all things photometric (as well as  
stock tips, political elections outcomes, and horse racing book...  :-)

Chuck Pullen


On Jan 11, 2006, at 11:00 AM, aavso-photometry-request at mira.aavso.org  
wrote:

>
> Message: 1
> Date: Wed, 11 Jan 2006 05:19:49 -0500
> From: "Robert J. Modic" <rjmodic at n2net.net>
> Subject: [Aavso-photometry] Ensemble photometry question
> To: <aavso-photometry at mira.aavso.org>
> Message-ID: <003f01c61698$8e6bb020$d500a8c0 at rjmodic>
> Content-Type: text/plain;	charset="Windows-1252"
>
> I wondering what the best method was to calculate the
> total error of an ensemble of comp stars.  I know that
> the error decreases with the square root of the number
> of comp stars.  Since each comp star has its own error
> that is usually different from other stars in the ensemble,
> what formula should I use?
>
> Bob Modic (MRV)
>
>