(cba:news) News and notes

Jonathan Kemp jk at cbastro.org
Wed Jan 30 05:08:40 EST 2002

Hi CBAers,

Just a few additional notes of possible interest...

A brief paper on RX 2329+06 has just been accepted for publication in
ApJL.  The abstract is included below and a link to the astro-ph preprint
(0201487) appears at the CBA web site in our publications section.
Please note that a more thorough treatment of the CBA photometry is in the
works and will appear soon!

Errata:  Apologies to Elena Pavlenko for omitting her in the list of WZ
authors and thanks to Alon Retter for noting that an extra paragraph from
the HP Lib abstract got mysteriously appended to the end of the WZ Sge
abstract in my last note.  Perhaps both signs that I need just a bit more

Lastly, Joe and I have had some discussions on authorship lately and I
thought I'd pass along some of his comments on the issue:


  The great bulk of the WZ Sge data motivated us to follow a more-or-less
  mathematical rule re authorship.  It's a one-percent rule.  The idea is
  that, like most observational papers, the work is about half data and
  half analysis/writing.  The data was about 1200 hours, so there's about
  2400 hours of "effective data" in the effort.  So we set about 24 hours
  (1%) as the threshold for authorship - awarding some extra points for
  nice longitudes, big glass, and great-quality data.  Some people logged
  vastly more (up to about 200) hours, so various co-observers (if any)
  rode in on their coat-tails.  Other people got - I hope! - warm
  acknowledgments and - surely! - some great karma awarded in that Great
  Scorebook in the Sky.

  This is pretty close to our standard practice.  I never really thought
  about it numerically before, but I think we've been applying a similar
  three-percent rule all along.  That would be *ruthless* for WZ Sge,
  though.  Anyway I don't guarantee 100% accuracy in our accounting (some
  guy named Arthur Anderson did the accounting, anybody ever heard of
  him?) - so I'll be happy to correct any mistakes that I or Anderson





1RXS J232953.9+062814:  A Dwarf Nova with a 64-minute Orbital Period and a
  Conspicuous Secondary Star
J. Thorstensen, W. Fenton, J. Patterson, J. Kemp, T. Krajci, & I. Baraffe
Astrophysical Journal, Letters
(accepter, January 2002)

We present spectroscopy and time-series photometry of the newly discovered
dwarf nova 1RXS J232953.9+062814. Photometry in superoutburst reveals a
superhump with a period of 66.06(6) minutes. The low state spectrum shows
Balmer and HeI emission on a blue continuum, and in addition shows a rich
absorption spectrum of type K4+-2. The absorption velocity is modulated
sinusoidally at P_orb=64.176(5) min, with semi-amplitude K=348(4) km s^-1.
The low-state light curve is double-humped at this period, and phased as
expected for ellipsoidal variations. The absorption strength does not vary
appreciably around the orbit. The orbital period is shorter than any other
cataclysmic variable save for a handful of helium-star systems and V485
Centauri (59 minutes). The secondary is much hotter than main sequence
stars of similar mass, but is well-matched by helium-enriched models,
indicating that the secondary evolved from a more massive progenitor. A
preliminary calculation in which a 1.2 M_solar star begins mass transfer
near the end of H burning matches this system's characteristics remarkably


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