(cba:news) december stars - plenty

Joe Patterson jop at astro.columbia.edu
Sat Dec 5 09:18:16 EST 2015


Dear CBAers,

The seasons, they go round and round... and we're captive on the 
carousel of time.  The first hard frost therefore means: time for a 
CBA-target change.

The glamor targets of the week are:
1. PM0333+3320 (the Thorstensen-Skinner-Lepine proper motion star). 
Possibly an "ordinary" dwarf nova now in superoutbrst... but perhaps 
very special because of the very high proper motion.  Such stars are 
probably quite nearby, and deserve very close attention.  Also the humps 
are now enormous.  Great northern target, now at mag 13.7, and at 03 33 
54.5 +33 20 05.

2. NSV 1440 = ASASSN-15sz.  Seemingly a far-south (Mensa) counterpart of 
CR Boo, with a very short Porb and now engaged in a series of echo 
outbursts (coming down from a supermax at 12.5).  The light curve yoyos 
a lot, but the periodic signal remains.  We need a few more weeks of 
coverage, if the star cooperates.

But for this and future weeks, here's an appealing menu of new stars.

3. HZ Puppis (8 03 22.8 -28 28 28.8) = Nova Pup 1963.  An obvious DQ Her 
system; we need another season to put it to rest.  We need some 
early-season (now) and late-season (April) runs to establish precise 
cycle count... and a big push in Jan-Feb to parse the somewhat intricate 
period structure (sidebands, etc.)

4. Swift J0614+17 (=2MASS 06141230+1704321) (6 14 12.28 +17 04 32.6). 
Another new DQ Her, which is discussed in astro-ph 1510.00703 (Halpern & 
Thorstensen).  V=17.5, but it's a healthy 23-minute signal.  We've been 
sporadically tracking it, but now it's time to pick up the pace and 
establish a precise ephemeris.

5. Swift J0503-28 (5 03 49.25 -28 23 8.8) V=18.1, so this is ambitious. 
Another DQ with P = 16 min.

6. Swift J0525.6+2416 (5 25 22.75 +24 13 33.5) V=16.6 and P = 4 min. 
Anoter DQ Her star, keep the exposure short to resolve the pulse.  BTW 
stars 4, 5, and 6 are ALL in the Halpern-Thorstensen paper described above:

http://arxiv.org/abs/1510.00703

7. V902 Mon (6 27 46.4 +1 48 11).  Eclipsing star, nature still unknown 
but likely to be a DQ Her or V Sge star.  Doesn't nicely fit into any 
known category, though.

8. V959 Mon = Nova Mon 2012 (6 39 38.74 +5 53 52.0).  Let's get another 
"seasonal" orbital light curve of this interesting gamma-ray nova.  7 
hours, so only long runs need apply.

9. T Pyx.  You bet!  It's time again.  The orbital period lurched upward 
suddenly during the outburst, and now appears to be resuming its 
"quiescent" positive Pdot - at least the last we checked.  We need 
another season - actually, just another month would suffice, to verify 
that the 2013-2014 behavior continues.


As for CURRENT (or recent) stars on the menu, I recommend dropping IM 
Eri and AH Men, and demoting AQ Men at least until NSV 1440 vanishes.
FS Aur is still good for an occasional run, but doesn't need anything 
steady.  Enrique will advise on 0644+33.

As usual, long runs on one target tends to be the most effective 
strategy.  But don't let the shiny new targets crowd out T Pyx!

joe
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