(cba:news) HU Aquarii, a new campaign target

Joe Patterson jop at astro.columbia.edu
Wed Aug 8 07:12:35 EDT 2018

Hi CBAers,

We're likely to have a hard X-ray (NUSTAR) observation of this star on 
August 17, and may have some Swift coverage before then also.  Now's a 
good time to start time -series observations.  The star is around 16.0, 
with very deep eclipses.  Hence probably an unfiltered target for most 
of us.  Someone, though, should try V (Gordon?), since these AM Her 
stars have very weird colors. Meaning: inferring V from "unfiltered" 
magnitudes is pretty uncertain.  In fact, come to think of it, everyone 
should consider taking some time to establish that relationship for 
their system.*

In Aquarius, thus an equal-opportunity target, plus transiting around 
midnight.  Let's get the program going in the next few nights - it'll 
also give us good baseline, plus some fallback insurance if August 17 
weather goes bad.

Recent interest in this star has been spurred by the relatively large 
variations in mid-eclipse timing - you know, planets, etc.  So I guess 
that's another reason to observe this guy.  But even if the planetary 
hypothesis goes pfffft (most do), there's still some pretty big wiggles 
in O-C, to be explained by some other astrophysical tool.  Maybe 
something related to the physics of CVs?  Hey, just a suggestion!

But... don't forget Maxie either... or VW Hyi (campaign still going for 
another ~2 days)!

joe p

*Don't go crazy with this, though.  It's just to get some idea.  Since 
comparison stars don't have "unfiltered" magnitudes, it's in principle 

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