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AAVSO Special Notice #87: New WZ Sge variable in Hya AAVSO HOME > publications > special notice

AAVSO Special Notice #87

New WZ Sge variable in Hya
January 5, 2008

VSNET announced the discovery of an optical transient
by Marcin Sokolowski of the "Pi of the Sky" group
(alert 9764, 12/21/2007).  Precise coordinates
were obtained at SRO (vsnet-alert 9772) and elsewhere:

11:12:17.40 -35:38:28.8 J2000
(SRO, UCAC2, errors less than 100mas)

A match was made by Brian Skiff (vsnet-alert 9769)
with a faint blue GSC2.3 star at
11 12 17.44 -35 38 30.1 J2000
with an arcsec coordinate error. At R=20.88 and proper motion
over several decades, the match is consistent.  This
gives an amplitude of about 8-9 magnitudes, about right
for a WZ Sge cataclysmic variable.

Hiroyuki Maehara (vsnet-alert 9778) analyzed images from Greg Bolt,
and found early superhumps with a period of about 0.05843d.

As reported by Daisaku Nogami (vsnet-alert 9782), Kenzo Kinugasa
has obtained optical spectra at GAO that indicate this is a
typical dwarf nova outburst with Halpha and HeI emission lines.

This object is now listed in VSX as
VSX J111217.4-353828
and can be plotted from VSP using that identifier.

A BVRI field calibration can be found at:
ftp://ftp.aavso.org/public/calib/j1112.dat

and a sequence extracted from this will be available shortly.

Last reports from SRO give the magnitude as V=13.8 and
remaining very blue, with no strong Halpha signal in the
Rc filter.  We expect this object to start fading shortly,
and ask observers to monitor it nightly, increasing your
observing cadence if you see it fade.
Arne
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