[vsnet-alert 15755] distance problem of SS Cyg

[Taichi Kato]

   This will be of interest to many readers.

   I also wonder if the authors were aware of the following paper,
or simply ignored it.

http://adsabs.harvard.edu/abs/2012AstBu..67..216V

===

arXiv:1305.5846
Date: Fri, 24 May 2013 20:01:09 GMT   (585kb)

Title: An accurate geometric distance to the compact binary SS Cygni vindicates
  accretion disc theory
Authors: J. C. A. Miller-Jones (1), G. R. Sivakoff (2 and 3), C. Knigge (4), E.
  G. K\"ording (5), M. Templeton (6), E. O. Waagen (6) ((1) ICRAR - Curtin, (2)
  U. Alberta, (3) U. Virginia, (4) U. Southampton, (5) U. Nijmegen, (6) AAVSO)
Categories: astro-ph.HE
Comments: 21 pages (8 as Supplementary Material), 3 figures (1 in the
  Supplementary Material). This is the authors' version of the work. It is
  posted here by permission of the AAAS for personal use, not for
  redistribution. The definitive version was published in Science in Vol. 340
  no. 6135 on 24 May 2013
Journal-ref: Science, 24 May 2013, Vol. 340, No. 6135, pp. 950-952
DOI: 10.1126/science.1237145
\\
  Dwarf novae are white dwarfs accreting matter from a nearby red dwarf
companion. Their regular outbursts are explained by a thermal-viscous
instability in the accretion disc, described by the disc instability model that
has since been successfully extended to other accreting systems. However, the
prototypical dwarf nova, SS Cygni, presents a major challenge to our
understanding of accretion disc theory. At the distance of 159 +/- 12 pc
measured by the Hubble Space Telescope, it is too luminous to be undergoing the
observed regular outbursts. Using very long baseline interferometric radio
observations, we report an accurate, model-independent distance to SS Cygni
that places the source significantly closer at 114 +/- 2 pc. This reconciles
the source behavior with our understanding of accretion disc theory in
accreting compact objects.
\\ ( http://arxiv.org/abs/1305.5846 ,  585kb)