(cba:news) March stars

Joe Patterson jop at astro.columbia.edu
Sun Mar 4 19:34:12 EST 2018

Dear CBAers,

Muchas gracias for all the great data you've been sending, especially re 
the DQ Her stars which you've been covering so faithfully.  It's been a 
winter of ice and mishap and hard work - nothing really serious but 
maybe I got kind of soft after a semester off from work.

The DQs are relatively sparse in the (northern) springtime sky, so that 
program can rest - a little.  Here are my recommendations for northern 

1. AT Cnc.  Probably a very ancient nova, and our last campaign showed a 
credible signal around 28 minutes.  Very desirable to get long runs now, 
the more the better.

2. NY Ser.  Reputed to be in a standstill state now around 15.5 - I 
think the first such event observed in this star's sparse history. 
Excellent morning target.

3. AM CVn.  Perhaps the least exciting star to observe (always within 
0.15 mag of 14.2), but very important since it is the prototype of one 
of the most important classes - the mass-transferring double white 
dwarfs.  We have a TENTATIVE detection of period change through 2016, 
but a good 2018 season should nail it down.  This calls for steady 
coverage through April (especially) and March.

4. HT Cam.  A DQ Her star for which we'd like to get a particularly 
accurate estimate of period change.

5. BK Lyn.  What's it doing this year?  Pretty steady, or cycling like 
the ER UMa stars.  Spot checks will be fine, not necessarily time series.

And for southern observers:

1. V598 Pup.  Lots of activity in this fascinating recent nova.  Except 
for Berto, who always seems to spot the most interesting jewels, we've 
never observed it before.

2. IM Nor.  Back in the sky now.  At 18.5, maybe only Gordon can work on 
it.  But some eclipse timings in the new season - i.e. maybe 20-25 hours 
of coverage - would be great to add to our >95% completed paper on this 

3. V959 Mon.  Another recent nona for which we need the 2018 orbital 
light curve.  It's a long period, so your runs need to be at least 4 hours.

4. WX Pyx.  Keep going on this one, the Pdot is still kinda insecure.
(I think; Enrique would know for sure).

And both hemispheres: SW Sex.  We've never done a good job on it, and 
there's no excuse for it.  ALL the SW Sexers have been good to us... so 
let's give the prototype a chance!

Those are my recs.  Enrique may send his, of course.


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