As an extra incentive, AT Cnc is currently in a Z Cam standstill. The
AAVSO data shows it "got stuck" around mag 13.6 near the end of
January. Although the data is a bit sparse, it seems to be showing a
0.4 mag amplitude variation with a ~6.5 day period. Interesting, but
possibly just a coincidence. It looks like I'll have mostly clear
skies tonight so I'll get a longish run on it from 0:30 - 06:30 UT
Shawn
On 03/04/2018 07:34 PM, Joe Patterson wrote:
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 observers:
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 star.
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.
joe
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