(cba:news) March stars

Joe Patterson jop at astro.columbia.edu
Tue Mar 1 08:58:34 EST 2016


Dear CBAers,

The new month brings retirements.

BH Lyn.  Done for the year.  Great orbital light curve, but the 
superhumps have vanished.

HZ Puppis.  Done for the month.  A few nights in April would be nice, to 
nail down the year-to-year cycle count.

T Pyx.  Paper finally submitted to MNRAS.  Should be on astro-ph today. 
  Whew!  A 10-year effort... slowed by laziness, greed, and the 2011 
eruption.

V902 Mon.  A really strange star.  Catalogued as an eclipsing DQ Her 
star, and we have some fine light curves.  But by my reckoning, the fast 
signals are *exactly* at the 6th and 13rd harmonics of the orbital 
frequency - and at no other harmonic.  Now *that's* a doozy!  We'll pick 
it up next year, and get a sharper test of just how exact this weird 
coincidence is.

And some other stars which very much need coverage now:

Swift J0503.7-2819. It's magnitude 18.4 and out of season, so won't be 
popular.  But a week of coverage now would be mighty nice!

Swift J0939.7-3224.  A long-Porb DQ Her star, at 17.3 not so 
unreasonable to cover.  But the long period (>8 hours) requires long 
runs AND well-separated longitudes, and so far we have only Gordon in 
eastern Australia.  Definitely a fine target for other longitudes!

Swift J0820.6-2805.  Don't know much about this one yet.  Only Gordon 
has tried it so far.  Still hoping we can learn something about this 
guy, but it's 18.4.

AM CVn.  Recent coverage has been good - keep it up, as *dense* coverage 
is ideal for disentangling the complex period structure.

Now some of the older DQs:

WX Pyx.  Definitely!  One of the most mysterious, and practically no 
published data on it.

V647 Aur, V667 Pup, MU Cam, and especially DW Cnc.  All needing coverage 
to establish long-term period evolution.

No actual dwarf novae in this message, and I'm also skipping a few 
novalikes only because I haven't studied the data.  Perhaps Enrique will 
supplement this message with some of the stars I've missed (AT Cnc?)

joe


The last message also contains some useful info (esp. the 
Halpern-Thorstensen paper)

http://cbastro.org/pipermail/cba-public/2016-February/000982.html
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