(cba:news) [vsnet-alert 4083] TmzV85's rapid fade (fwd)

[Jonathan Kemp]

for those of you who may not subscribe to vsnet...

---------- Forwarded message ----------
Date: Thu, 27 Jan 2000 14:07:01 -0500 (EST)
From: Joe Patterson <jop at astro.columbia.edu>
To: vsnet-alert at kusastro.kyoto-u.ac.jp
Subject: (cba:news) [vsnet-alert 4083] TmzV85's rapid fade


             TAKAMIZAWA V85: UP POPS THE WHITE DWARF


Does it get any better than this?

On the night just ended in Arizona, JD 570.67-571.07, we obtained a 9.6
hour run with the MDM 1.3 m telescope.  The star was in rapid decline
throughout, fading from V=16.31 to 16.77.  There were still periodic
waves, but their nature (superhumps? orbital?) is still unknown as they
were greatly dissimilar to the waves seen even 1 day earlier.  Very
deep eclipses (>2 mag deep) occurred throughout, and the light was
dominated by a small hot object at the center of the disk.  This is
likely to be the white dwarf - anyway, it's very small (most of the
eclipse drop occurs in 40 seconds!) and very hot (>40000 K if it's
actually the white dwarf).

How wonderful is this!  We've always wanted to measure the effects of
the outburst on white dwarf heating.  Nature draws a knife-edge across
the white-dwarf face every 106 min, and we can accurately isolate the
contribution of the white dwarf.  Presumably it will cool rapidly at
first, then slowly... but who knows, that's why we do the experiment.

We've been observing TmzV85 from the start, and are managing to splice
together long time-series photometry from our various sites.  We'd
greatly welcome other observers in our collaboration.  TmzV85 will rise
again some day, possibly soon, and we conspire on other stars too (at
present, BY Cam, CN Ori, and FS Aur).  Come visit our web site and
consider joining us.

       http://www.cbastro.org

Center for Backyard Astrophysics (TmzV85 cabal)

Joe Patterson -    CBA New York  jop at astro.columbia.edu
Jonathan Kemp -    CBA Oracle
Lasse Jensen  -    CBA Denmark
Tonny Vanmunster - CBA Belgium
David Skillman -   CBA East
Brian Martin -     CBA Alberta
Bob Fried -        CBA Braeside