(cba:news) summer stars

Joe Patterson jop at astro.columbia.edu
Thu Jun 26 18:15:28 EDT 1997

   Dear CBAers,                                  June 26, 1997.

        Back now from the round of June meetings.  No great
   things coming out of them, but several very promising
   inquiries arriving at our website while we were gone. Some
   good expansion prospects in Russia, Western Australia, New
   York, and Colorado.  All sites that we would greatly welcome.

        I wanted mainly to cover program stars for June/July.
   For the small telescopes, the best targets are V Sagittae and
   V603 Aquilae.  That's it.  Pound 'em into the ground.  Both
   very bright, about 11.5, and surviving any conditions of
   moonlight.  FO Aquarii would be a nice project too, very
   entertaining with its 21 minute pulse.

        The bigger telescopes have a more complex menu.  In the
   early evening, we still want timings of AM CVn (especially)
   and HP Lib = EC1533-1403, as long as you can get 2-hour runs
   on them (after the runs get shorter, we declare the seasons
   over).  But we also want to keep a very close watch on V844
   Her = Var43 Her, now at magnitude 17.5 but still seemingly
   humping away.  For those of you with already a commitment to
   this star (esp. Dave E and Dave W), I recommend keeping it
   up; I realize the data *look* ugly, but they seem to be
   paying off in the overall time series.  Later in the night,
   there's V503 Cyg, an old buddy which we deserted for a couple
   years.  It's a great permanent negative superhumper, and it's
   time to make friends again. It's about mag 17.2, sorry about
   that, but the superhump is about 0.4 mag amplitude, plenty
   big.  We should hit it hard, long, and often throughout the

       That's also true for our old friend RX1940-10 (=Aquila 1
   in Downes-Webbink-Shara 1997), now back in the sky.  Brighter
   (averaging about 15.6) and with a very large hump, about 0.5-
   0.7 mag.  For the larger telescopes, it's perhaps best to
   declare allegiance to either RX1940 or V503 Cyg depending on
   your aperture and latitude.  Lemme know which one you'll go
   for, and I'll keep people apprised of wha's happenin'.
       Oh, and FO Aqr is fine for short observations with any
   size telescope and pretty much any moonlight.  With a large
   21 minute pulse it's hard to go wrong.  Naturally we always
   like the long observations though!  This star will give you 
   something really nice to hang on your mantle.
       If you're just starting in this business, by the way, I
   recommend V Sge, because the light curve is relatively
   predictable (not entirely), and it will be easier to evaluate
   the data.  I'm also writing a paper on the star now, and am
   maximally motivated to provide that evaluation!  The comparable 
   southern/equatorial target is V603 Aql.

        Finally... Last year at this time, the Europeans got some 
   good data on DQ Her, and I said we would mount a serious effort
   in 1997.  I was planning to welch on that promise.  However,
   Dave Skillman just got five straight nights on the star, and we
   do have a 2-week dark run starting now.  It would be *awfully*
   interesting to know if DQ Her showed superhumps (totally forbidden
   by all theories of course!) - and last year's data was kinda
   tantalizing.  The star's certainly well placed.  So, Lasse and 
   Tonny, let's say that if you get a good weather streak in the 
   next 5-7 days, go for long runs on DQ Her, tell us by cba-info, 
   and we'll support it in North America.  I'm a bit reluctant to 
   starve some of these other stars which are sure winners, but this 
   may be a big chance.  (But if your weather's bad, let us know that 
   too, so we can be undisturbed by Mister DQ.)


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