(cba:news) a new stellar menu

Joe Patterson jop at astro.columbia.edu
Sat Oct 9 23:04:44 EDT 2010

Dear CBAers,

The recent haul of data for program stars has been really great.  It'll 
take me quite to assimilate it all... but I can see now that we've met 
objectives for XSS0056+45, V709 Cas, and IGR0023+61.  All DQ Her stars 
that we want to revisit briefly *late* in the observing season 
(February?), in order to nail down cycle count.  We have, however, 
secured the unique dividends that we get only from long time series.
Exit left, to applause.

In the evening sky, two DQ Hers that we still haven't got enough on are: 
RX2133+51 and V2306 Cyg.  The latter, especially, is showing a complex 
multi-periodic structure I didn't expect; it may be too late in the 
season to decode this, but at a dec=+32 and multi-longitude 
observations, we might succeed.

And an oddity in the evening sky.  HR Lyr, a classical nova remnant 
which has been at ~15 for many decades. has apparently declined to 17th 
magnitude.  A bit out of season... but cab someone find out what the 
light curve looks like in this strange - and unprecedented - state.

And in the morning sky, I again urge coverage of RX0704+26 (Gem) and 
RX0636+35 (Aur).  Especially the former, which may reward you with 
glorious light curves if you can manage a time resolution less than ~50 s.

Now for dwarf novae.  Many of you have contributed mightily to the 
campaign on SDSS0804+51 (Lyn).  A very important star!  (Probably a 
really ancient CV.)  Question is: when to stop?  It's still flashing 
echoes, but I suspect that time series during these echoes will not have 
much probative value.  I could be wrong... but the humps decline to near 
zero amplitude at the tops of echoes - and the limited duration of runs 
is a big handicap.  *Maybe* it has a week of life left in it, and maybe 
less.  Just use your own intuition on this one - if the light curves 
still look good, then it's *certainly* worth continuing.

One of the new CSS transients looks pretty interesting:, with about 2.2 
hr superhumps: CSS 000938.3-121017 (chart and light curve on CSS website 
- which identifies the stars by *date* preceding the coords).  Could be 

V455 And remains good, and so does BW Scl.  Still not much action on 
these this...  but they're the New York Yankees of CVs.


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