[vsnet-alert 1195] Rebrightening of USNO 1425.09823278

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

Rebrightening of USNO 1425.09823278

  As reported by several groups, the above new dwarf nova is undergoing
a post-(super)outburst rebrightening.  Summary of observations up to now:

  YYMMDD(UT)   mag  observer
  970904.488   133  (S. Takahashi)
  970904.792   134  (T. Kinnunen)
  970904.810   137  (T. Kinnunen)
  970904.819   135  (J. Pietz)
  970904.822   134  (T. Kinnunen)
  970904.847   137  (T. Kinnunen)
  970904.860   135  (J. Pietz)
  970904.863   136  (T. Kinnunen)
  970904.885   135  (T. Kinnunen)
  970904.891   134  (G. Poyner)
  970904.892   134  (G. Poyner)
  970904.910   135  (T. Kinnunen)
  970904.933   137  (T. Kinnunen)
  970905.021   135  (P. Schmeer)
  970905.110   138  (B. King)
  970905.780   138  (T. Kinnunen)
  970905.806   137  (T. Kinnunen)
  970905.883   136  (G. Poyner)
  970906.017   137  (G. Poyner)
  970906.810   139  (J. Pietz)
  970906.831  14.45  (L. T. Jensen, CCD unfiltered)
  970906.890   140  (J. Pietz)
  970906.980   140  (J. Pietz)
  970907.810   155  (L. T. Jensen, CCD unfiltered)
  970907.837   153  (T. Kinnunen)
  970907.869   154: (G. Poyner)
  970907.926   155: (G. Poyner)
  970907.938   157  (T. Kinnunen)
  970909.007  <147  (G. Poyner)
  970909.772  <147  (T. Kinnunen)
  970909.823  <165  (L. T. Jensen, CCD unfiltered)
  970909.974  <147  (G. Poyner)
  970910.824  14.68  (L. T. Jensen, CCD unfiltered)
  970910.836  14.68  (L. T. Jensen, CCD unfiltered)
  970910.838  14.71  (L. T. Jensen, CCD unfiltered)
  970910.880   142  (J. Pietz)

  The interval between the fading from the main outburst (presumably a
superoutburst) and the rebrightening is only 3 days, which is one of the
shortest ever observed in SU UMa-type dwarf novae.  Such "early rebrightening"
was only observed on very few occasions such as the 1978 superoutburst of
WZ Sge and the 1995 superoutburst of AL Com, both of which are notable
examples of so-called "WZ Sge-type dwarf novae".  The present pheonomenon
observed in USNO 1425.09823278 may be somehow related to these rarely observed
specimens.  Since the regrowth of superhumps during the rebrightening stage
was reported in AL Com, we strongly urge observers to monitor this object
closely until the final quiescence is confidently reached.

Regards,
Taichi Kato

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