[Aavso-photometry] Chart Generator for EPS AUR

[Steven Orlando]

Jeff and Mike,

I know it is a bright star, but how can you get an accurate mag if you don't 
have comp stars.

Of course, you can use a 35mm camera lens to widen the field. I don't have a 
50 mm camera lens. I can use an 80 mm camera lens.

What I understand is that as long as you get epsilon and lambda Aur in the 
same field, you can do photometry.

Please post the link to the procedure you write up. I am interested in 
taking a look at it.

Steve
----- Original Message ----- 
From: "Jeff Hopkins" <phxjeff at hposoft.com>
To: "Steven Orlando" <sorlando at sorlando.com>; 
<aavso-photometry at mira.aavso.org>; <aavso-discussion at mira.aavso.org>
Sent: Monday, January 21, 2008 8:38 PM
Subject: Re: [Aavso-photometry] Chart Generator for EPS AUR


> Hi Steve,
>
> Epsilon Aurigae is a 3rd magnitude (V) star and pretty easy to find, right 
> next to Capella and at the vertex of the triangle known as the kids. 
> Lambda Aurigae is the normal comparison star. While there are other stars 
> closer, they are too faint for CCD work in that if you stay linear with 
> epsilon the comparison stars will be in the noise. For CCD photometry 
> there are two major problems, the brightness and wide separation of 
> program and comparison stars.
>
> Bob Buchheim wrote an article for the SAS Vol. 5 Number 3 Newsletter 
> titled "Getting Ready for Epsilon Aurigae." He indicated the problem with 
> CCD photometry and the brightness of epsilon Aurigae. He suggested 
> stopping down the telescope, but that does not solve the separation 
> (around 5 degrees) of the program and comparison star.
>
> At HPO we have investigate using a 50mm F/2.0 camera lens on a DSI Pro. 
> Preliminary results are very encouraging. Both epsilon and lambda Aurigae 
> fit in the image and by defocusing the image a bit under sampling is 
> solved. Several nights have produce BVRI data where 3 sets were 0.01 
> magnitude or between data spread. I'm in the process of writing up the 
> procedure. While this is CCD filter photometry, it is very different from 
> CCD photometry of fainter stars.
>
> Of course the star system works best with single channel photometry. For 
> more information check
> http://www.hposoft.com/Campaign09.html
>
> Jeff
>
>
> At 18:26 -0700 01/21/2008, Steven Orlando wrote:
>>Hello All!
>>
>>On the homepage, there was a call for data for EPS AUR. However, when I go 
>>to  plot a chart I get no photometric start for my FOV.
>>
>>Anyone have a link to a star chart for this star?
>>
>>Steve
>>_______________________________________________
>>
>>Aavso-photometry mailing list
>>Aavso-photometry at mira.aavso.org
>>http://www.aavso.org/mailman/listinfo/aavso-photometry
>
> -- 
> Jeff Hopkins
> HPO SOFT
> Counting Photons
> http://www.hposoft.com/Astro/astro.html
> Hopkins Phoenix Observatory
> 7812 West Clayton Drive
> Phoenix, Arizona 85033-2439 U.S.A.
> (623)849-5889
> (623) 247-1190 (Fax)
> www.hposoft.com