[vsnet-alert 10598] V1251 Cyg rare (super)outburst!

[Taichi Kato]

   As reported by a number of observers, the SU UMa-type dwarf nova
V1251 Cyg is undergoing one of its rare outburst (being in the high
northern sky, it is unlikely many outbursts have been missed).
The last confirmed outburst (superoutburst) was in 1997 Sep.,
when the object reached a relatively faint maximum (mag 13.3).
The object underwent a similar faint superoutburst in 1994 Dec. -
1995 Jan. (superhumps were confirmed).
The earlier (first-ever outburst since its discovery as a potential
nova) outburst was in 1991 Oct., when then object underwent a bright
outburst similar to the current, and the discovery in 1963, ones
(cf. IAUC 5377; IBVS 123, IBVS 3689).  The observation of the 1991
superoutburst is available in IBVS 4152.

  The outburst properties and development of superhumps were unusual
for an SU UMa-type dwarf nova with a superhump period of 0.07604 d
(large outburst amplitude, rare outbursts, no or rare normal outbursts,
relatively slow development of superhumps).  These properties may
suggest that V1251 Cyg behaves as if it is the longest-Psh analog of
WZ Sge-type dwarf novae (see also PASJ 53, 1191, "HV Vir and WZ Sge-Type
Dwarf Novae").

  Time-resolved photometry during the current outburst is most critically
desired!!

  YYYYMMDD(UT)   mag  observer
  20081016.998  <16.10C  (Gary Poyner)
  20081017.794  <170C  (Jochen Pietz)
  20081018.794  <146  (Eddy Muyllaert)
  20081018.842  169C  (Jochen Pietz)
  20081019.790  <133  (Patrick Schmeer)
  20081019.790  <133  (Patrick Schmeer)
  20081019.865   125  (Eddy Muyllaert)
  20081019.871   124  (Patrick Schmeer)
  20081019.871   124  (Patrick Schmeer)
  20081019.881  127C  (Jochen Pietz)
  20081019.883   124  (Hubert Hautecler)
  20081019.940  12.62V  (Etienne Morelle)