[Aavso-photometry] variable comp star in field of TT Ari?

[Richard Huziak]

Hi Jim,

The only suspect in the field is NSV 15440 far to the SW.

0201+14   TT ARI      
0201+14B  93 VAR? SW = NSV 15440 = See AAVSO Circular 183, 1986

Check also if you have a stuck filter shooting B when you think it is V.  I've had this happen.  However, hope you've discovered a new one :-)
Sure wish I'd clear up! Maybe later tonite.

rick


Jim Roe wrote:
> I started watching TT Ari on Sunday night, did a time series of some 280 
> points, reduced the data using the 111 (11.075) star close to TT Ari as 
> reference and everything looked fine.  The comp stars were nice and 
> repeatable so I uploaded the batch.
>
> Last night I again got a nice sequence, used the same reference star and 
> comps but, compared to the night before, both comps were nearly 0.2 mag 
> off from the night before.  As I suspected the reference star to be at 
> fault, I re-ran the images using a different reference star but added a 
> couple more comp stars and used the (previous) reference star as a comp. 
>   Here is a table showing the differences between Sunday night and 
> Monday night.
>
> delta(111) = 0.134 (0.04)
> delta(146) = -0.038 (0.053)
> delta(118) = -0.069 (0.011)
> delta(131) = -0.060 (0.016)
>
> Ref (on both sets of data) = 125(12.494).
>
> where the sense of the subtraction is Sunday result minus Monday result 
> and the star designations are from the TT Ari chart 071025.  It looks to 
> me like the 111(11.075) star brightened substantially in one day. 
> Comments, questions?
>
> Jim Roe [ROE]
> Wentzville, Missouri
>
>
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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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