(cba:news) Happier hunting...
jop at astro.columbia.edu
Fri Feb 28 13:12:07 EST 2003
OK, Tom Ridge says you can remove the duct tape now - so back to your
telescopes! Unless... hmmm, I've got it - you're penalizing me for
promoting loser stars to campaign status. I admit they weren't too
exciting... but maybe we can find a middle ground here.
We tend not to chase dwarf novae really hard. The superhumps are lots of
fun to track, but the science return is a lot less after one eruption has
been well covered, since the superhumps don't vary a great deal from one
supermax to another. (They do vary *some*, and eventually one might learn
something deep from those variations - but that payoff will be on a very
long timescale.) That's why, for example, I've declined to promote KS UMa
in its present supermax - although some CBAers, especially Tonny, have
getting beautiful data.
I also tend to like the novalikes better, because one can really plan an
observational campaign, without relying on the serendipity of outburst.
With very long coverage one can reach very sensitive limits - especially
because the stars don't change state appreciably in the course of the
campaign, which limits sensitivity in the case of dwarf novae.
But admittedly, some of the novalikes don't show periodic humps to
relevant CBA limits (say .07 mag in one night, or .02-0.03 mag in a long
time series). That's scientifically interesting (we still don't quite
know exactly which stars superhump - there has *never* been a paper which
actually established this on any solid footing), but not as much fun to
observe. Still, about half of them do... and just cuz I'm on a losing
streak now, I won't always be.
I'm writing all this because a few weeks ago EC0556 kind of fizzled for
us, and UMa7 doesn't appear to be doing too well. Both UMa7 and EC1056-29
are showing some variability, but nothing much and nothing periodic - so
far. So far the runs on UMa7 have been kinda short, so I'm not sure it's
yet time to move on. I think we should probably wave goodbye to EC1056,
I have two new bright stars to recommend for the start of campaigns. One
is HQ Mon, the other EC11588-3142 ("Hya" in the CV Catalogue). Both
bright, and the first equatorial, and no periods yet known on the planet.
So the summary of stars I'm recommending:
Northern: UMa7 (maybe - depending on your inclination), HQ Mon, FS Aur (to
get late-season timings of its strange 3 hour variation), DW Cnc
Southern: HQ Mon, EC11588-3142.
And it would be great if there were an intrepid northerner that could get
down to -31 degrees... our time-series for southern objects is usually
missing the Americas, and even a 2.5 hour observation at that longitude is
likely to be really valuable.
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