[vsnet-outburst 7694] GW Lib: genuine superhumps, initial growth also recorded

[Taichi Kato]

Dear all,

   As Arai-san and Uemura-san reported, genuine superhumps
were definitely detected on April 23 (Nakajima-san, Hiroshima
observations, and Kyoto observations).  Part of the data
is being analyzed and we will be able to duly inform updated
results.

   Berto Monard has also kindly sent observations up to late
April 21.  A period analysis of the data has shown the
superhump signal (genuine superhumps) was already present
on April 20 and 21.  The period from Monard's observations
(interval April 20-21) was 0.05417(6) d.  The period using
newly developed hierarchical Bayesian modeling yields a very
good agreement.  The period excess from the earliest observation
was 1.5(1)%.  The very earliest stage of the superhump evolution
was thus fortunately recorded.

   The mean amplitude was 0.009 mag (singly humped).