[Aavso-photometry] HD37605 photometry/possible field variable

[Shawn Dvorak (RHO)]

The 86 comp on the AAVSO chart is GSC 0127 0230 and the 99 comp is GSC 0127 
0220.  A second night of data shows a similar variation of about 0.008 mag 
in the 99 star.  Using data from 12/26-27 I estimated ToMx of 53366.688 and 
53366.767, giving a rough period 0.079d.  The light curve from 12/27-28 
yielded another peak at 53367.795, and from that I get a period of about 
0.0791d.  As John Greaves mentioned, this is quite reasonable for a delta 
Scutid.  Graphs of the two nights' data are available at 
http://www.rollinghillsobs.org/hd37605.html

No sign of any change in HD37605 at the few-millimag level are apparent on 
either night.  Clouds preclude any observations tonight.

Shawn


----- Original Message ----- 
From: "Pertti Pääkkönen" <ppaakko at cc.joensuu.fi>
To: "Shawn Dvorak (RHO)" <rollinghillsobs at cfl.rr.com>
Sent: Tuesday, December 28, 2004 3:18 AM
Subject: Re: [Aavso-photometry] HD37605 photometry/possible field variable


> Hi,
>
> Please give us an identification (GSC, SAO, or RA/dec) of your suspected 
> variable. We
> may collect a lot of data of theis as well during this campaign.
>
> I will also try HD37605 with our 20" Cass. using B filter and 180 sec 
> exposures
> because of our high airmass (>1.8) in Finland. Provided that these damned 
> clouds
> disappear some day!
>
> Best regards,
>
> Pertti (PPK)
>
> Lainaus "Shawn Dvorak (RHO)" <rollinghillsobs at cfl.rr.com>:
>
>> I got a good run on HD37605 last night 03:13 to 06:55 UT.  The skies were 
>> quite
>> transparent and probably as close to photometric as we can get here near 
>> sea level
>> in Florida.  There was no sign of any change in HD37605 even at the 
>> few-millimag
>> level.  This star is just about the perfect brightness for V filter 
>> photometry
>> with my 25cm: I was able to go with 10sec images to avoid scintillation 
>> effects,
>> but still collected plenty of photons.
>>
>> While reducing the data I did notice that one of the comp/chk stars I 
>> used *may*
>> be variable.  When plotting the brightness of the 86 comp against the 99 
>> chk I see
>> a sinusoidal curve with an amplitude of about 0.006 mag and a period 
>> around 0.08d
>> (~2 hours).  Unfortunately there's no other stars bright enough in the 
>> field to
>> provide a secondary check to see which of the two stars is variable (if 
>> either).
>> You can see a graph of the light curves at
>> http://www.rollinghillsobs.org/images/HD37605_2004-12-26.jpg
>>
>> Shawn Dvorak (DKS)
>> Clermont, FL
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>>
>>
>
>
> -- 
> Pertti Pääkkönen, PhD, Laboratory engineer
> University of Joensuu, Department of Physics
> Tel: +358 13 351 3238
> Fax: +358 13 251 3290
>