(cba:news) RZ LMi forever...

Joe Patterson jop at astro.columbia.edu
Tue Jan 30 08:52:46 EST 2001

Dear CBAers,

Here's what I sent to vsnet a couple days ago.  Since then, Brian Martin
and Lew Cook have popped up with some superoutburst coverage, and Jeff
Robertson tells me that he has been watching the star for several years.
Great news. But in this campaign - which I hope will decide these
interesting issues since they rely on very dense coverage - weather has
turned bad everywhere in the USA.  So we are "sailing blind".  Plus our
(snowy and soggy) MDM run is practically over.  We just need to keep
hitting the star.  Take no prisoners, and we'll surely find the buried
treasure.  Forgive the mixed metaphors, and fire that ol' telescope up!

                       RZ LEONIS MINORIS

     Since the work of Robertson et al. 1995 (PASP 107, 443) and Nogami et
al. 1995 (PASJ 47, 897), this star has been known to be the most frantic
dwarf nova in the sky, with superoutbursts popping off every 20
days.  Five years ago we conducted a long CBA campaign, and found two
tantalizing results: that the superhumps did not die in quiescence (as
required by law), and that they did not lose track of phase from one
superoutburst to the next (as required by another law).  The data were 
not, however, sufficient to prove either of these beyond doubt.

     Such criminal acts among stars are often the prelude to a deeper
understanding.  So we have launched another long campaign to do
time-series photometry of RZ LMi through mid-April of 2001.  We seek
much help from other observers.  About 3 months of coverage are needed,
and this requires a lot of teamwork since it exceeds any one person's
energy level (OK, with the possible exception of persons named Kato or
Skiff...).  Our basic need is long unfiltered time series (say >3 hrs
per night) of differential photometry.  An account of possible observing
procedures is given at our website (https://cbastro.org and
click on "data" and "charts"), but we can handle different formats and
observing strategies by using overlaps to normalize the data.

     The star varies between about 17.2 at quiescence (where it hardly
ever sits) and 14.8 in superoutburst.  It's still in superoutburst at
this moment (Jan 27). In addition to the ~20 day superoutbursts, it 
also has short outbursts on a ~4 day timescale... jumps around a lot.
Can you help us learn about this nervous star?  Write and tell us if
you can help.

Joe Patterson jop at astro.columbia.edu

so far, Elena Pavlenko - Crimean Observatory
        Jonathan Kemp - CBA-Hilo
        Tonny Vanmunster - CBA-Belgium   
        Dave Skillman - CBA-Maryland

More information about the cba-public mailing list