[Aavso-photometry] Possible Bottlenecks for Using a small telescope

[Richard Huziak]

Hi Tom et al,

I saw are response to this regarding looking through NLCs.  But I can 
answer the aurora question since I live in the Land of Perpetual Aurora, 
and doing photometry through it is an interesting trick.  The bottom 
line is that if there is aurora present anywhere in the sky, you have 
increased sky glow everywhere.  This in itself is not a big issue - you 
just can't shoot as deep, but everything else remains the same.  When 
the aurora gets more active, a few different scenarios happen.  With 
diffuse, moving displays, and provided the displays don't get too bright 
or move into your field of view, again - this just looks like more sky 
glow.  But when rays get big and bright, the sky and photometry begin to 
behave like you have cirrus clouds everywhere, and you find that images 
get gradients all over them the same as when cirrus moves in and out.  
The difference with aurora is that your 'cirrus' also gets brighter and 
dimmer as it wishes.  So once the aurora flares up, I go outside and 
enjoy the show - not much more you can do to look through it 
successfully.  But if the aurora is minor and background conditions are 
not popping up and down in brightness constantly, it is photometry as 
usual.  There is no detectable colour shift or other effects that one 
might dream up - just background brightness issues or gradient frames to 
manage or discard.  I keep good observing notes and note my sky 
conditions so that if I get wonky results on what should have seemingly 
been a good night, I can go back and see if I had aurora or NLCs or 
other things that could affect the quality of the data.

rick

Tom Krajci wrote:
>
> Will you have to deal with frequent auroral activity that brightens the 
> sky background?  Will you still take data then?  (I'm mostly curious on 
> this matter...I have no practical experience.)
>
> Feel free to contact me if you have more questions.
>
>
>
>   

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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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