(cba:news) (No) curtain call for RZ Gru

Joe Patterson jop at astro.columbia.edu
Tue Aug 23 07:48:33 EDT 2005


Dear CBAers,

Time marches on, and the script calls for RZ Gru to exit stage left.  It's
been a good campaign, mainly Berto plus the usual New Zealand
powerhouses... and will take me a few weeks to analyze fully, but I can
see from a quick look that we'll profit more from new targets than from
repeated observation.  So away with it - we'll see if it surrenders a
period at last.

Still a good southern target, and one never observed before with time
series, is V1082 Sgr.  At 15th mag it should give a pretty good signal -
let's visit a while before the Sun drags it away.

And in morning skies, there's VZ Scl.  At 3.5 hours and eclipsing, it's
somewhat criminal that we've never observed it before.  Such stars are
prime candidates for superhumps, and often flash other showy credentials
when closely examined.  Help us avoid serious jail time by starting up the
year's activity on VZ Scl.  About 15.7, a nice challenge to get good
signal-to-noise in the time series.

And IN THE NORTH...

I still hunger greatly for coverage of MN Dra and IX Dra.  Even snapshot
mags in the low state have value.  But not much CBAer interest yet.

The response to "Dra" (HS1813+62) has been better, with contributions from
Dave Messier, Lew Cook, and Michael Richmond.  But the time series still
needs some more *density* to acquire serious punch.  A late-season effort
on Mister Dra would be just great!

FINALLY (all hemispheres)...

There's also the possibility of jail time for failing to observe AE
Aquarii for lo-these-many-years.  With small and mainly filterless scopes,
we're not well equipped to observe it.  Yet it's bright (11-12), transits
at local midnight, nicely perched on the celestial equator, is deeply
entangled in some awfully interesting magnetospheric physics (because of
its rapid 33 second rotation)... and will be the target of practically
every space telescope this August 31-Sep 1.  So starting now, we really
ought to be accumulating light curve to support these space observations.
You'll see that AE Aqr is often just dead flat in the light curve - with
flares erupting every few minutes to every few hours.  By far the best
method is to use a blue filter (to subdue the unwanted light from the
secondary, and isolate the flaring region).  But unfiltered time series
will still be plenty helpful.  All the other time-series photometry
considerations apply normally.  More on this as the coordinated
observation dates approach.

So there's a new August/September menu.  I'm just going off for some late
summer family time before school starts.  The northern-USA heat wave has
finally broken (today), and now I'm heading off to northern Maine where
the ocean temperature never exceeds 53 degrees F!

joe





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