(cba:news) changing stellart fashions

Joe Patterson jop at astro.columbia.edu
Thu Jan 9 23:14:19 EST 1997


Dear CBAers,                                         Jan. 10, 1997.

As most of you know, EG Cnc is continuing to light up the solstice sky
with eruptions and photometric waves.  The "main event" of the
superoutburst ended about December 18, but since then the star has
jumped back to mag 13.5 on 3 occasions (every 7 days or so; each time
it falls back to about mag 16.  We obtained very good coverage when the
superhumps were strong (December 6-13 or so), but coverage since then
has not been good.  Jonathan has been observing it for a week straight
at Cerro Tololo, but it's quite a strain at -30 degrees.  Also, his
light curves have shown only quite small wiggles.  Such things
considered, I'm inclined to declare the EG Cnc campaign over.  Unless
the star stages another full-fledged superoutburst, let's quit.

Oh, and ditto for PX And.  This campaign was entirely successful,
yielding strong negative and positive superhumps.  But evening twilight
has ended it.

As I stated last time, I really wanted to promote BH Lyn as the best
northern target for January.  I still do.  But yesterday brought the
news of a BZ UMa outburst; if it's a *long* outburst, it would be a
very good target.  (BH Lyn can wait a bit since it's not an eruptive
star.)  The best comp star is 2.5 arcmin west of the variable, at V =
13.77 (and unfiltered CCD mag about 13.3 I think).  For the smallest
telescopes, you might want to select the brighter comp star another 1
arcmin WSW.  A good chart is in Downes & Shara, and the 2000 coords of
BZ UMa are 8 53 44.3 +57 48 40.  This is an excellent target for the
smallest telescopes, and a good one for all telescopes, but be warned
that most of the outbursts are short -- no betting the farm on this
one.

You can, however, bet the farm on BH Lyn and DW UMa, and these are the
prime objects for winter observing.

For the australites, we're doing campaigns on Men 1 = H0551-819 (main
target) and RR Pic (back-up).  We also would love snapshots and short
time series on V803 Cen for the rest of the observing season (6 more
months).

                                        joe





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