(cba:news) SS UMi, YY Dra, YY Sex

Joe Patterson jop at astro.columbia.edu
Mon May 6 08:19:12 EDT 2013


Hi CBAers,

A few other stars to clarify their status.  Enrique has started up the 
SS UMi season, and for northerners, strangely enough, the star is in 
excellent position for observation.  The star is now around 17th and 
showing a strong periodic signal, and likely more than one.  Just our 
cup o' tea... but we greatly need coverage at USA longitudes to 
unambiguously define the period structure.  This star may give trouble 
since it's a frequent erupter... but I think it's probably interesting 
enough to declare all-out war (coverage at all luminosity states).  But 
FOR SURE it's a great target at 17th magnitude - and get a LONG time series.

Time to bury YY Sex.  Very entertaining star, with huge humps, 
especially in I light.  But the period is rock-stable, and there is no 
second period as asserted in the literature.  Nor is it a reflection 
effect, as also stated in the only publication on the star.  Just a 
garden-variety AM Herculis star.  But we have some great data, and it'll 
be a cute little paper.

Also time to bury YY Dra.  The coverage, especially by Enrique, Jim 
Jones, and David Cejudo, has been good; but the detections of the fast 
period signals (9 and 4.5 minutes) have been *borderline*, and that's 
not sufficiently convincing when there are FOUR candidate signals (w, 
w-w_orb, 2w, 2w-2w_orb).

Is anyone (in the CBA orbit) planning to go to the SAS conference in Big 
Bear this year?  We usually go, but won't this year, mainly because of a 
Kitt Peak observing run coinciding exactly with the dates.  The program 
seemed low on variable stars, and very low on CVs.  We'll make a big 
push for next year, though.  Meanwhile, is anyone planning to go?  I'd 
like to announce here, to help you guys, if any, find each other.

joe



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