(cba:news) 2QZ0219-30 and SWIFT J1734-01

Joe Patterson jop at astro.columbia.edu
Wed Jul 13 19:49:10 EDT 2005

Dear CBAers,

Back home now and able to read email.  Whew.

It'll take me a few days to study the recent data.  But two things are

1. Berto's discovery of superhumps in the new dwarf nova 2QZ0219-30 (also
known as 2dF etc. and also as "For" in the Downes catalog) is quite
important because of its location in/near the period gap.  Let's track
this guy around the Earth and as late as possible... even to quiescence in
the (admittedly unlikely) event we can get that faint.  A bright new
superhumper, reaching 12th magnitude, near the Galactic pole and flirting
with the period gap... this deserves a LOT of attention!

2. The new SWIFT transient - possibly a black-hole transient - is a very
good target too.  In 2000 a similar event occurred and Lew Cook found a
4-hour wave in the light curve, which turned out to be a superhump.  A
half-dozen stars have flashed similar things at us in the past, though
never as well documented.  It's likely that the amplitude will be low, or
the period long (which might amount to the same thing, since you might see
only a fraction of the amplitude)... but should yield a signal if one
exists and if we can amass coverage over a wide range of longitudes.

3. Good time to quit on RX1730-05.  This star is tough now, and it's time
to quit.

4. Two northern dwarf novae, lightly observed and now possessing firm
orbital periods (newly measured by John Thorstensen), are crying out for a
superhump period measurement.  (That's the faint wail you hear on a really
quiet and dark night.)  Yet they're SO lightly observed that we don't even
know outburst recurrence periods... won't you please help us measure 'em?

More in a few days, as I work though the data and messages...


More information about the cba-public mailing list