(cba:news) No turkeys on the menu!
jop at astro.columbia.edu
Tue Dec 3 13:39:10 EST 2002
Definitely not. The campaign on Tau 2 is starting to yield its result.
Our coverage is still dominated by USA longitudes (Dave S, Jerry F, Cap'n
Bob, David Messier), but some contributions have come in from Bob Rea and
Tonny (NZ and Belgium). So we've overcome simple aliasing, though the
domination by one longitude still inflicts avoidable noise on the power
spectrum. Anyway, the main story seems to be this: three signals in the
power spectrum, a positive superhump at Po+3.4%, a negative superhump at
Po-2.7%, and the nodal signal itself at 6 days. Cute! And damned
interesting... at this Po, the positive superhump is expected at about
Po+8%, so this implies a low mass ratio - which we can maybe make hay of.
(Where did that expression come from, anyway?)
We have to sharpen accuracy, and also explore the higher harmonics, which
are still a bit weak. We have about 12 more days before the Moon will
interrupt us - let's try to get tree-to-tree coverage until then.
Especially those treasured and exotic longitudes oh-so-far from 90 degrees
The other great star is EC0422-20. This one is *really* easy to do - very
attractive target for small scopes, even if the declination is a trifle
unappealing. For this one, our dominant coverage is from Berto and Greg
Bolt (Pretoria and Perth), so our more common artillery in the USA and NZ
haven't yet arrived in force - except for Lew Cook, whose data breaks the
cycle-count logjam. The star shows BIG-TIME negative superhumps at 3.32
Those are the two CBA targets for the south. For the north too - in a
full display of hemispheric brotherhood I hope. But we get some extra
hours of darkness in the north. I recommend short (1-2 hr) observations
of FO Aqr and AO Psc if you'd like an early-evening target.
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