[vsnet-chat 914] Re: Magnitudes, sequences, etc

[Seiichiro Kiyota <skiyota@abr.affrc.go.jp>]

In message "[vsnet-chat 881] Re: Magnitudes, sequences, etc",
William S G Walker wrote...
>The only problem with all of this is that it begins to show up the
>limitations of the telescope and charts. After locating V803 last night in
>about 30 seconds I then spent an hour trying to get the star on the CCD
>frame. Both the field orientation and the eyepiece had been changed to
>improve matters- which confused the mind a little! It doesn't help that the
>observatory is now an attic at the other end of the house from the computer
>(which will change soon) but it's becoming clear that the camera needs to
>be set up like the conventional photometer with a field eyepiece,
>retractable mirror and all that! The eyes are never dark adapted - you have
>to look for faint objects on the computer screen - and there is not usually
>a bright star nearby. Even the CCD responses differ - mine produces images
>which don't entirely match the Taichi Kato and the CBA charts. So it's not
>always as simple as it sounds. I can see why many amateur CCD people stick
>to easily identified fields. It's something of a change from a 50cm Zeiss
>or a 41cm B & C to a backyard 10" Meade LX - the first of the LX series!

Before I began to use Vixcen Atlax equatorial mounting with automatically 
pointing (assistant) system, I also seem much difficult to introduce target 
variables to CCD frames. Yes, small filed of view of CCD and star diagonal 
for eyepiece to check filed are main reasons. These automatic-pointing devices 
may help you. I think that there are many choices for LX series telescope.  
Recently I key in R.A. and Dec. only for a variables  and I can introduce 
a target into CCD .

I also use Megastar 4.0 software - chart software commercially available based 
on GSC-  on my PC to confirm filed and position of variables. CRT monitor for CCD 
frames and chart (Megastar) set up side by side. PC based chart software is very 
useful because scale of chart is easy to change and I can easy to check pointing error.

Of course, I also use Ouda and CBA charts and catalog of cataclysmic variables 
by Downs and Shara for check as position of CVs in GCVS ( used in Megastar) sometimes 
has large error.  



I think recent discussions are very useful to exchange information about amateur CCD photometry.
Thank you for Vsnet-vhaters.

                                                        Seiichiro Kiyota

----
 Seiichiro Kiyota  skiyota@abr.affrc.go.jp
 Laboratory of Stress Physiology
 Department of Plant Physiology
 National Insititute of Agrobiological Resources
 Tel:81-298-38-8384
 Fax:81-298-38-8347

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