From jop at astro.columbia.edu  Mon Jan  1 04:51:55 2001
From: jop at astro.columbia.edu (Joe Patterson)
Date: Mon, 1 Jan 2001 04:51:55 -0500 (EST)
Subject: (cba:news) CU Vel
Message-ID: <Pine.SOL.4.05.10101010449230.9802-100000@tristram.phys.columbia.edu>


Dear (southern) CBAers,

By the way, CU Vel is presently in outburst.  If this is a superoutburst -
prospects look good right now - then this is a very good target.  There
are some hard-to-interpret periods in the (slim) documentary record for
this star, and we surely need some new data to steer us out of the
confusion!

                 joe



From jk at cbastro.org  Fri Jan 12 02:40:52 2001
From: jk at cbastro.org (Jonathan Kemp)
Date: Thu, 11 Jan 2001 21:40:52 -1000 (HST)
Subject: No subject
Message-ID: <Pine.GSO.4.10.10101112137090.3394-100000@ohia.jach.hawaii.edu>

Hi CBAers,

Just a quick note to let you know that Joe and I are still alive and
kicking.  We've just returned from a conference in Taiwan on
small-telescope astronomy.  Unfortunately, Joe had an illness and was
briefly hospitalized.  So, it'll be a few days yet before we both
completely recover from our adventures and get fully up to speed.  I
believe that RZ Leo and TW Pic continue to be fine targets du jour...

Jonathan
CBA Hilo


From jk at cbastro.org  Wed Jan 17 07:08:07 2001
From: jk at cbastro.org (Jonathan Kemp)
Date: Wed, 17 Jan 2001 02:08:07 -1000 (HST)
Subject: (cba:news) A new SU UMa for mid-year from the MACHO Project
Message-ID: <Pine.GSO.4.10.10101152133270.15661-100000@ohia.jach.hawaii.edu>

A new CV of possible interest to some of you...

Jonathan

---------- Forwarded message ----------
Date: Mon, 15 Jan 2001 20:44:42 -0500 (EST)
From: Doug Welch <welch at physics.mcmaster.ca>
To: Jonathan Kemp <jk at cbastro.org>
Subject: (cba:news) A new SU UMa for mid-year from the MACHO Project

=============================================================

DISCOVERY OF SU UMA-TYPE CATACLYSMIC VARIABLE
     D.L. Welch, McMaster University, on behalf of the MACHO
collaboration (cf. IAUC 6312), reports the discovery of an
SU UMa-type cataclysmic variable in the MACHO Project photometry
database, confirmed by inspection of images. The variable is
located at R.A. = 18h03m06s.03, Decl. = -27o30'45".5 (equinox
2000.0) and normally appears V=18.8 mag or fainter. 
During the period 1997 March 9.74 to 1999 Oct 21.40 UT, the 
MACHO Project collected 1165 observations of this object with 
the Mt. Stromlo 1.27-m telescope and normal outbursts appeared 
at intervals of approximately 10 days. Normal outbursts typically
peaked at V=16.6 mag.  At least six superoutbursts occured during 
this period, with peak brightnesses of about V=15.6 mag and 
durations of 10 days or longer. Finding charts, lightcurve plots 
and data can be obtained at http://www.macho.mcmaster.ca/CV/index.html.


From jop at astro.columbia.edu  Fri Jan 19 14:26:03 2001
From: jop at astro.columbia.edu (Joe Patterson)
Date: Fri, 19 Jan 2001 14:26:03 -0500 (EST)
Subject: (cba:news) January stars
Message-ID: <Pine.SOL.4.05.10101191333010.13404-100000@tristram.phys.columbia.edu>


Dear CBAers,

Well, I think I am finally recovered from my seizures in Taiwan.
Without Jonathan's help I'd be struggling to get out of the country
(and maybe even the hotel), but now I've managed to give two classes
and can even remember the names of all these CVs.  Ten days ago I
didn't know my own name.  Redundant storage, what a great idea that
was.

We - Jonathan and two trainees - start an observing run tonight at Kitt
Peak.  The top priority is RZ LMI AT QUIESCENCE.  RZ LMi is perhaps the
most active of all the hydrogen-rich dwarf novae, and it's debatable
whether it ever even reaches quiescence.  Anyway, it does sometimes slink
down to 17th mag, which is about the right ballpark.  The main point is to
track the peroperties of the superhumps through say two complete cycles of
supermax, max, quiescence.  When we tried this six years ago, we found
something pretty amazing: the superhumps really never went away, and
didn't lose coherence either.  They seemed actually to maintain coherence
over 5 consecutive supermaxima.  I couldn't prove it though; superhumps
are always a little slippery, and it will take more persistent coverage to
prove or disprove the case.

We assign high priority to RZ LMi at other phases of the outburst
cycle too, since otherwise there can be no chance of tracking the star
continuously.  Superoutburst, especially, should be very interesting
since the signal is strong and we should learn many of the finer details
about the superhump (quasi-harmonics etc.).  

The other northern target is BH Lyn, an eclipsing SW Sex star which has
shown both positive and negative superhumps in past years.  Except in
eclipse, this star is always about 14.7, so it's one that just about
everyone can do.  It's time to get one more intense 3-week look at the
star, and then publish the results.

In the south, Robert Rea and Maria Marsh have been waging a heroic
campaign on TW Pic from New Zealand.  The case for a 10-hour period looks
pretty good, and Brian Warner tells me they have several nights from
South Africa which should break the aliases.  However, it is perhaps the
strangest looking power spectrum I ever saw, and one of the strangest
light curves - up/down episodes of 1 magnitude which last <2 hours.  I
can't figure this guy out yet, it just doesn't fit pre-existing boxes.
We should continue for at least another week, then re-evaluate.

Finally, there's T Pyx, back in the midnight sky.  This is the galaxy's
only short-period CV of very high luminosity, and previous evidence
suggests the 1.8 hr binary period is changing rapidly.  A couple weeks
of coverage now, and then again 8-10 weeks later, will give us two lovely
new points to plunk on the O-C curve.  Won't you help us generate such
lovely points?

    joe



From jop at astro.columbia.edu  Tue Jan 23 19:01:54 2001
From: jop at astro.columbia.edu (Joe Patterson)
Date: Tue, 23 Jan 2001 19:01:54 -0500 (EST)
Subject: (cba:news) RZ LMi flames into superoutburst
Message-ID: <Pine.SOL.4.05.10101231848130.1845-100000@tristram.phys.columbia.edu>


Dear CBAers,

Last night, Jonathan found RZ LMi just freshly jumped into superoutburst,
with shiny new superhumps.  So to the borealites out there, at all
longitudes, it's time for a strong campaign on this star!

The usual stuff, coords and finding chart, at the CBA website (under
/charts/old).

Happy, happy.


                    joe



From jop at astro.columbia.edu  Tue Jan 30 08:52:46 2001
From: jop at astro.columbia.edu (Joe Patterson)
Date: Tue, 30 Jan 2001 08:52:46 -0500 (EST)
Subject: (cba:news) RZ LMi forever...
Message-ID: <Pine.SOL.4.05.10101300839160.15742-100000@tristram.phys.columbia.edu>


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

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