The Other Hemisphere

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Thu, 6 Aug 1998 16:38:49 -0400 (EDT) · jop_at_astro.columbia.edu

Dear (mostly southern) CBAers,                         Aug 6, 1998.

CV news lately has had a rather northern bias.  This is to
remedy that shameless display of hemispheric incorrectness!

The one star for which we are continuing long coverage is V1432 Aql =
RX1940-10.  In a couple days the Moon will be outa the way, and I hope
that you take a crack at this star.  We do need somewhat long coverage
though (>3 hr).  It averages about mag 15.5 so will be hard for the
smallest scopes.  On the other hand the modulation is very large, a
full magnitude and that's not counting the very deep eclipse.

But most of the stars I have to recommend are easier.

We finished with V1315 Aql, and now want to turn to the next SW Sex
star up there.  That's UU Aqr (not Aquilae, which is also a CV, but
Aquarii).  It's usually at magnitude 13.5, very nice for all of us.
It gets attacked by the Moon once a month, but at this brightness the
attack is brief.  I especially recommend it for the next 10 days;
Jonathan is in Chile and it's a very good time to get long runs at
other longitudes so we can resolve cycle-count issues.  By the way, it
eclipses every 3.9 hrs, and a finding chart is in the original Downes-
Shara atlas (Feb 1993 PASP).

There are three good DQ Her stars lurking up there these days: V1223
Sgr, FO Aqr, and AO Psc.  We need pulse timings for all three .  The
advantage of these is that you get a result (a pulse timing) in about
1.5-2 hr, a pretty good return on investment.  And they're nice 'n
bright (13.7 or so).  And you can scatter the coverage as much as you
like, because the period changes we look for are long-term -- over
years.  Whereas our superhump studies greatly reward *density* of
coverage - long runs on successive nights.

We're finished for the year with V603 Aql and V1315 Aql.

We still want coverage on V592 Cas, TT Ari, V Sge!  Really nice objects
for northern smallscopers.  Long runs very desirable.

V1504 Cyg is superhumping as we had hoped; Tonny and Dave West got nice
light curves on the same night, and I think Elena did too.  A few more
nights should give an accurate period measurement.  As for that helium
star in Draco, well it's a faint sucker and so far I'm not sure anyone
has gotten a time series.  But maybe.  Maybe Mike Schwartz.

There's an article on the CBA coming out in the October issue of S&T, I
think.  Thanks to all who sent pics.  I think that they will say nice
things about us (especially since they let me write most of it).
Unfortunately they did edit out a table with names and scopes of
CBAers; that was a bummer.  But I hope it'll lead to more expansion
into distant lands.  I also hope to see some of you, maybe, at the
Canadian "Starfest" in two weeks.

For Stan and Paul and Marc (our rather amazing New Zealanders): I
really recommend UU Aqr for a few weeks!

joe