[vsnet-alert 12093] XMMU J115113.3-623730 orbital period

[Taichi Kato]

XMMU J115113.3-623730 orbital period

   Berto Monard have reported a set of recent observations.  Combined with
observations by Chris Stockdale and Greg Bolt, we have been able to establish
the orbital period 0.36055(3) d.  The amplitude is 0.43 mag, with an
almost sinusoidal profile.  The profile suggests a reflection-type
variation by a high-temperature white dwarf now emitting supersoft X-rays.
There are also superimposed 0.1-mag shorter-time variation.
The overall behavior is similar to other supersoft sources, particularly
QR And (which also underwent a number of historical and recent very slow
nova-like brightenings; the object smoothly declined by 1.5 mag since
1999).