[vsnet-outburst 8897] CH UMa in outburst again?

Thu May 1 01:20:00 JST 2008

AAVSO observers report the brightening of CH UMa:

  YYYYMMDD(UT)   mag  observer
  20080427.248  <143  (Patrick Abbott)
  20080430.068   130  (Glenn Chaple)
  20080430.085   128  (John Bortle)

If the outburst is confirmed, this is only 116 days since the previous 
one - exceptionally short interval compared to the average cycle of 370 
days for this star.  But CH UMa has been "misbehaving" during last two 
years: there were 543 days between Nov. 2005 and May 2007 outbursts 
followed by the unusual slow outburst in Jan. 2008.  Looks like 
something strange is going on with the accretion rate in this 
(previously quite regular) system.  Definitely worth monitoring!

Denis