[Aavso-photometry] HMXB charts

[Richard Huziak]

Hi all,

To let you know, I have been running time-series and spot hits on most 
of these fields for about 1-1/2 seasons in early support of Gord's 
project.  Next week (kind of busy otherwise right now), I will be able 
to give some direction on these fields and answer questions, and 
especially while Gord is on the 82"  (I will be doing the 2nd half of 
the 82" run).  I have talked to Arne about the existing and newly found 
variables in these fields.  You can identify these by reading the notes 
on the charts.  Most of the new variables have had very little work done 
on them, and after I get a list of them to Elizabeth, you will be able 
to report these secondary variables to the dbase as well.  They will 
also be entered into VSX asap.  So please reduce for these stars at the 
same time you are doing the target, and I'm sure others will be 
discovered in the process.  I will also be able to give some advice on 
the variability of the target stars in terms of amplitude, period, etc, 
to help you set up your runs, but will do that to personal respondants 
due to data concerns before publication.  What I can say is that 
generally, variability is not large and good data can be a challenge to 
obtain.

Quickly, on 2206+543, b & D are new variables
              on V2175 Cyg, g is an 'ALS' luminous star, and sometimes 
these are variable, but I haven't look at this field much.  Currently, 
it is our standard star.
              on V831 Cas, there are a large number of dSct and Be 
stars, plus one new EA - at least 16 variables within the field shown 
(all the "W's"), plus a whack of others  in the core of NGC 663 beyond 
the image borders to the SW.  Be careful here when choosing ensemble 
stars, though I have found no problems with p & b.  Most of the dSct and 
Be stars vary by only a few hundredths.  

All the target variables vary such that all-night continuous time-series 
are the most useful, though nighty, hourly spot hits are also useful for 
longer period determination.  If doing spot hits, please take & reduce 5 
sequential images to avoid any spurious issues (not single frames). 
 Bottom line is that we have a lot of work to do to understand every 
aspect of these stars.

rick (HUZ)

Gordon Sarty wrote:

>The HMXB charts on
>
>http://www.usask.ca/psychology/sarty/AAVSO_HMXB_Charts.html
>
>are all updated and are stable barring problems like the discovery of a 
>variable comp star. Please use the updated charts and submit your 
>observations directly to WebObs. We should be able to track the data in 
>the light curve generator as usual.
>
>Clear Skies!
>Gord
>
>
>  
>
>>All four fields *have* been observed at SRO, and BVRcIc photometry
>>is available.  I expect Gordon and Richard to extract the magnitudes
>>for their comp stars sometime soon.  I agree that "d" is too red
>>for a good comparison star.
>>
>>This will be a tough campaign, as there are 4 targets to follow
>>(instead of just SS Cyg); the necessary precision will tax your
>>ability to perform photometry (a good thing!); combining datasets
>>that have not been transformed will require significant overlap;
>>long time series will show trends due to extinction; etc.
>>
>>    
>>
>
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>
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>  
>

-- 

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Richard Huziak
Manufacturing Engineering
SED Systems
Saskatoon, SK, Canada
tel. (306) 933-1676
<huziak at SEDSystems.ca>
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