(cba:news) Fwd: new stars for mid-January

Joe Patterson jop at astro.columbia.edu
Thu Jan 17 22:17:13 EST 2013

Dear CBAers,

We finally reached critical mass on T Pyx.  I sent off an ATel
(#4743)which reported the new orbital period - kind of a shocker since
it implies a very large mass was ejected, inconsistent with the modern
understanding of recurrent novae.  Compared to Mario Livio's published
1991 prediction, the actual measurement is 7 times larger - and of the
opposite sign!  We can now take a little break from T Pyx.  We need to
pick it up again in March-April, to make sure the new period is truly
stable; it certainly oughta be, but T Pyx has surprised us at every turn...

BTW our journal paper on T Pyx (with all the authors, not just the few
in the ATel), supplying all the details behind this brief report and
trying to wrestle with understanding T Pyx in the context of binary
evolution, is about two weeks from a first draft.  The nova conference
in South Africa gives me a hard deadline.

At this exact moment in time, I recommend that very high priority be
given to:
(1) Nova Mon 2012: 06 39 38.57 +05 53 53.0, probably now about 13th mag.
The main period is 7 hours, so you'll want a LONG time series; 1-2
hours won't be useful.  We'll probably be observing this celebrity star
for many years - let's get acquainted with it!

(2) CSS130106:112619+084651 ("OT1126")  Let's ratchet up the pressure on 
this interesting WZ Sge type star.  Also will reward very long time 
series... but even the 2-hour variety will be useful.

And next tier of priority for

(3) ES Cet, DW Cnc, RX0704+26, Swift0732-13, HT Cam, CP Pup, V382 Vel 
(if it's still bright enough).  And V455 And, IF you can manage a cycle 
time of 15 s or less.

That still leaves the ER UMa stars for separate discussion.  The stars 
very thoroughly observed last year were ER UMa and BK Lyn; we don't need 
to make a big push this year, but we must spot-check them to make sure 
they don't go off the proverbial reservation (change their properties 
drastically).  I think that the major campaign on V1159 Ori is worth 
continuing 1 more week, and then stop; Enrique might want to countermand 
that, however.  We still haven't had much luck with RZ LMi, and that 
one's really quite a good target.

Most of the stars will reward faithfulness - staying with one star 
rather than one-night stands.  The exception is most DQ Hers.

For southerners who would like one star to stick with it for many weeks 
on end (I sure like data sets like that!), think about CP Pup.  It's 
time to figure out the periodic signals of this fascinating and 
incredibly elusive star!  RR Pic is another good choice; we haven't 
observed that one for years.

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