(cba:news) ER UMa, SDSS1339, CP Pup, BK Lyn, DW UMa
jop at astro.columbia.edu
Wed Mar 2 17:28:03 EST 2011
Wow, what a bunch of stars in February. ER UMa and SDSS1339+48 continue
to light up our sky with beautiful periodic variations! The signals in
ER UMa must surely tell us a lot, because they are large-amplitude in a
bright star, and very phase-stable. Just ideal for the long term study
that has never been feasible in any other star - because the signal
vanishes, the star vanishes, or the stability is too low to follow
definitively. Keep the faith on through the next superoutburst, and a
little beyond - i.e. at least 3 more weeks.
SDSS1339+48 still hasn't shown its hand, just recently dropping down to
V=15. Will it show echoes? Will the humps stay around for months like
WZ Sge/GW Lib? Will the periodic WD pulsations return soon? Will the
unexplained large 7 hr period at quiescence pop back up again? All
unknown, At some level, we're going to want to follow this throughout
the (northern) spring. Definitely good for long time series, which as
usual are much more valuable than the short guys.
And I have to say, at great risk of crying "fire" too often, that CP
Puppis is even more interesting. I was SHOCKED by the first few light
curves of Bob Rea - showing a very strong periodic signal at a period
considerably shorter than the alleged Porb. That weird signal is still
there, but it now appears to be multiperiodic - and it will take a good
multi-longitude set of time series to unravel it (separate the closely
spaced components). Berto and Bob are doing well with it, and some
observations from the southern USA (Tom K and Shawn Dvorak) have been
very helpful. I really hope that Greg Bolt (Perth), or some Aussies,
can get some suitable runs on it.
More generally, I think 2011 is going to be a breakout year for negative
superhumps. For years they have been trying, and mostly failing, to
break out from my computer. Now they have to, having been liberated by
the black magic of ER UMa.
There's so much new stuff, I'm not nearly caught up. But I have learned
all that. My preliminary analysis on BH Lyn is negative - no
discernible humps (other than the variation-cum-eclipse at Porb). So
that's probably done for the year. The other two (likely) bright stars
to go after now are BK Lyn and DW UMa - also fine negative-superhump
specimens that have not been properly published yet.
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