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AAVSO Special Notice #81: Possible Nova/X-ray Transient AAVSO HOME > publications > special notice

AAVSO Special Notice #81

Possible Nova/X-ray Transient
November 18, 2007

Read et al. (ATEL 1282) report the discovery by XMM-Newton
of a very bright new transient, XMMSL1 J070542.7-381442,
located at
07:05:42.7 -38:14:42 J2000
with an error radius of 8 arcsec.  It was detected in a slew
that took place on October 8, showing an extremely soft
spectrum.  Since it is in the galactic plane where there
is large column density (extinction), they suggest that it
is Galactic in origin and perhaps very close.  They proposed
an optical counterpart of USNO-A2.0 0450-03360039 (which
has a Bmag=15.7 and Rmag=15.9, indicating a blue object).

Torres et al. (ATEL 1285) observed the object on Nov. 16
with the Magellan 6.5m telescope, finding a bright saturated star
with typical nova lines, but most likely in the auroral
phase - that is, long past the peak of the nova outburst.

Images from Shawn Dvorak and Bill Allen indicate that the
USNO-A2.0 star has brightened to about V=10.5 currently;
the peak brightness is unknown at this time.

VizieR is still not back up, and we cannot give precise
coordinates at this time.  A further notice will be issued
with more details when they are available.  In the meantime,
we suggest observing visually using nearby ASAS comparison
stars, or using a V filter and time series with a CCD camera.
Do not observe unfiltered since the spectrum is full of
emission lines.

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