jumpy stars

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Thu, 12 Dec 1996 14:46:24 -0500 · jop_at_astro.columbia.edu

               ERUPTING AND OTHERWISE JUMPY STARS             12/12/96


     We're getting fairly good coverage of EG Cnc from U.S. observers
(Harvey, Shafter, Fried, Skillman), and the star continues to flash
textbook superhumps at us.  We don't have much coverage from other
longitudes, and I hope this can be remedied as the superhump will
become harder to follow later as the star fades.  It's worth a special
effort since these supermaxima seem to be mighty rare (only known one
in history was in 1977).  If you would like to receive the current
light curve showing the superhumps, let me know - I have it ready to
send at the push of a few buttons.

     PX And = PG0027+260 = And 1 is wonderful; I imagine you're getting
tired of reading that but I wanted to plug it again in the hope that we
can keep up strong coverage through about January 10.  We're quite
fond of "comp 1" on the CBA charts, the star 3.5 arcmin north of the
variable, and we're awfully happy with unfiltered photometry on
typically red-sensitive CCDs.  Delighted, in fact.

     Our southern friends have likely been at the beach too long
while we hard-working borealites have been looking at EG Cnc or at
least the clouds in front of EG Cnc.  But now there's a (likely)
superhumper for the other hemisphere.  Jonathan Kemp sent me
confirmation of CU Vel's outburst, first announced yesterday by Hers in
the vs-net.  This is another rare erupter, and there has never been a
good study of its superhumps.  So we will likely start tonight, and
earnestly hope that we will have some help from other longitudes.  Will
we?  Please let me know if you think you might be able to get time-
series photometry on it -- that knowledge will spur us to greater
devotion.  The star is presently about 11.3 so does not necessarily
require a CCD (in fact, it's possible that the humps may even be
visible by eyeball).

     More items for australites.  We demoted RR Pic in our observing
plans, because it failed to display a superhump in a ten-night light
curve.  A serious breach of ethics.  Nevertheless, it's quite a good
target for small telescopes, and I recommend it as the *best* southern
target for people just now getting "on the air".  We're spending more
time on H0551-819 = Men 1, also a fine target since the star is bright
and has an interesting period structure; but it has a companion just 3-
4 arcsec away, so you'll have to decide what to do about that.  Large-
telescope folks should consider H0709-36 = Pup 1, a great star with
eclipses and superhumps; but it's faint (15.5) and in a moderately
crowded star field.

     We also have a bunch of stars near 9 hr right ascension (north and
south) discussed in the newsletter - won't repeat the discussion here,
bit it'd be nice to get started on these guys.

             joe