[vsnet-alert 8943] QX Nor optical outburst (ATEL)

[Taichi Kato]

   According to ATEL, the X-ray nova QX Nor is undergoing an optical
outburst.

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The Astronomer's Telegram                   http://www.astronomerstelegram.org 
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Posted: Sun Jul  9 01:30:01 EDT 2006 -- Mon Jul 10 01:30:01 EDT 2006
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ATEL #855							     ATEL #855

Title:		optical outburst of 4u 1608-522 (=QX Nor)
Author:	Charles D Bailyn (Yale)
Queries:	charles.bailyn at yale.edu
Posted:	9 Jul 2006;  16:04  UT
Subjects:	Optical, Binaries, Neutron Stars, Transients

SMARTS consortium observations with the 1.3m telescope at CTIO + ANDICAM
instrument show    that QX Normae, the optical counterpart of 4U 1608-522,
is in outburst (see Markwardt   et al. ATEL 851 for a description of the
current high energy outburst).  We obtained   a 12m I-band image starting
at UT=2:01 July 9 2006 that showed the optical counterpart   to be comparable
in magnitude to comparison star #7 (I=18.7) from Wachter 1997 (ApJ 485,
839).   Precise measurements were hard to obtain from this image due to
bad conditions and    scattered light, but QX Nor is clearly well above
its quiescent brightness of I>21    (Wachter et al. 2002 568, 901), and
within the range of the "Low Intensity State"   described by Wachter et
al.