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(cba:news) targets for January 2015: T Pyx, CP Pup, HZ Pup, and especially ASASSN-14mv (Joe Patterson) [2014-12-31T19:36:42Z]


Dear CBAers,

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 it out).

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 is over.

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 discovered. See
http://www.astronomy.ohio-state.edu/~assassin/transients.html
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!

joe
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