the active roster

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Sun, 20 Sep 1998 10:35:02 -0400 (EDT) · jop_at_astro.columbia.edu

Dear CBAers,                                       Sept. 20, 1998.

A few things have changed significantly since I wrote last 5 days ago.
Coverage of the two dwarf novae in Cygnus (V1028 and V630) has been good.
We still need some small-telescope coverage (esp. V1028) while they're
bright and still accessible; then we'll kick back in with the bigger 
scopes after they grow faint (perhaps in 7-10 days?).  Still good targets
for most of us, but probably only for about 10 more days.

Oh, and V1974 Cyg is solved!  As more or less expected, the seasonal
power spectrum showed two closely spaced periods (orbital + extra).  
But as no one could have expected, the extra period was *shorter* than
Porb this season, unlike 1994-1996.  Negative superhump.  No trace of
the positive.  Just the opposite of TT Ari's transition the previous
year.

Mighty interesting.  But not, I think, deserving of more observation
this year, unless we can get some *substantial* amount of good photometry
at non-USA longitudes.  No sign of that so far, so I'm ready to call it
a year and move on.

As I mentioned earlier, we're also sounding taps for V592 Herculis, V 
Sagittae, and UU Aquarii. 

In the midnight and morning skies, V592 Cas and TT Ari are very good
targets for coverage throughout the fall, especially for smallscopers.

Not much coverage on HL Aqr yet.  Very well placed in the sky, friendly 
to all at magnitude 13.5, and nicely astride the equator.  A CBA dream.
The amplitude is low, but then so is the (flickering) noise, so...
let 'er rip.

And for a far-southern target... AH Men = H0551-819 has wheeled back 
into view.  Not that it ever really falls out of view, but now it's 
back available for long runs.  Let's crank up for a fine season!

Now for a really, really tough one.  As many of you know, we're awfully
fond of the helium stars, and have invested at least 200 hours each on
AM CVn, CR Boo, HP Lib, and V803 Cen (counting Stan, Paul, and Marc on 
the last, a Kiwi specialty).  Now we are trying the hardest of all, CP
Eri.  It varies from about 16.5 to 19.8.  Perhaps absurdly faint at
quiescence, but we've been doing it with a 1.3 m telescope - and what a
treat this star is!  It flashes by far the most transparent power spectrum
of any star in this class.  But we definitely need help - from other
longitudes to break aliasing, and from any longitude to follow it over
the course of the observing season.  Warren and John, this might be just
right for you.  Or perhaps for steady monitoring with the SARA telescope
(Matt)  Or Tim, for old times' sake!

                   joe