(cba:news) targets for January 2015: T Pyx, CP Pup, HZ Pup, and especially ASASSN-14mv
jop at astro.columbia.edu
Wed Dec 31 14:33:26 EST 2014
Out with the old (except DQ Hers), in with the new (or newly re-acquainted).
ASASSN-14ei has had a glorious year, with steady observation from NZ
(Bob Rea), South Africa (Berto), Chile (Josch), and especially Australia
(Gordon). 5 solid months, nearly every night, spanning the Earth, with
the star showing a superoutburst followed by 12 echoes (and counting).
The superhumps endure throughout, and their coherence (stability in
phase) is amazing. Basic period of 42.9 minutes, with numerous
harmonics. Wow. Apparently the helium stars can manage much better
stability than the H guys. Food for thought (but I doubt I can figger
Anyway, it's time to END THE CAMPAIGN. Evening twilight is shortening
the runs, and there's just too much low-hanging fruit out there to keep
going. UNLESS there's another 12th magnitude superoutburst - *that*
would be worth an encore performance.
There are *numerous* excellent targets well-placed in the southern sky
this month. These are:
1. T Pyx. Occasional all-night (or very lengthy) runs will do the job.
We need only ten more over the whole Jan-Feb-Mar observing season.
2. HZ Pup (=Nova Pup 1963). Last year we found the periodic signals
confirming its identity as a DQ Her star. Now it's time to test the
long-term stability (certify its remembrance of phase from 2014 to
2015). We definitely want long runs - and the most desirable time
window is the next two weeks (subject to moonlight limitations of
course), because we have an observing run on the MDM 2.4m then. We
can't get long runs on Puppis of course, but can provide observations
linking South Africa to AU/NZ. About 17th mag.
3. CP Puppis. Prime season for this fascinating star. We seem to know
its Porb (88 minutes), and we know the large photometric humps occur at
a slightly longer period. Sounds familiar, right? Au contraire! The
variations are not understandable as superhumps, and are much less
stable. To understand them, we need to get coverage as global as
possible. Perhaps this should wait until the present bright-moon period
4. V959 Mon. Definitely want lengthy runs for this 2012 nova.
The two very high priority stars are:
1. WX Ari. The lengthy 2014 low state continues, with the star at 19th
magnitude. I know it sounds quixotic, but if you can possibly get a 3-4
hour time series on this star - maybe with a red filter to subdue
moonlight - it would be very rewarding!
2. ASASSN-14mv. A star (dwarf nova??) just erupted, and just
Josch's first night on this star, just communicated on cba-chat, show
obvious fast waves in this star (I assume it's a star). very well
placed for lenthy runs. Around 13-14 magnitude. A sensational way to
end one year and start the next!
The other good northern targets are DQ Hers (intermediate polars). You
know the drill on these guys, and maybe you even have your favorites.
Most of them need coverage, and most can accept several-hour runs.
Longer is always better, but a few hours is usually good enough. The
ones particularly starved for coverage are: HT Cam, V647 Aur, V667 Pup,
DW Cnc, and WX Pyx.
Happy observing in 2015!
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