[vsnet-alert 15862] PNV J19150199+0719471: still stage B, continue observing

[Taichi Kato]

PNV J19150199+0719471: still stage B, continue observing

   We have received further data from Josch Hambsch, Willian Stein,
Arto Oksanen, Greg Bolt, Enrique de Miguel.  The object still shows
stage B superhumps (with positive Pdot).  The superhump profile,
however, has changed considerably.   Observations have been getting
sparse in the last one or two days.  Our experience tells that
most of important phenomena in the past (dramatic fading stage,
stage transition etc) suffered from the lack of observation.
This is quite understandable: decreasing enthusiasm as the event
lasts for a long time, decreasing superhump signal which would
appear less appealing.  However, the decreasing superhump signal
indicates that a new phase with different phenomenon is approaching,
and please continue observing.  Many transients are discovered
in the dark (moonless) nights, and after a typical duration of
the outburst, the Moon also tends to interfere the observation
of an important change in the state.  Our crucial observations
for WZ Sge-type dwarf novae include whether the superhump phase
jumps and how the superhump period varies during the rapid fading.
This phase can be very easily missed, and will not be seen for
tens of years for the same object.
Please consider this bias and try to obtain as much data as possible
particularly when the Moon is bright.