[vsnet-outburst 8971] CR Boo: superoutburst

[Makoto Uemura]

CR Boo: superoutburst

Last night (15 May), we found that CR Boo was very bright.

YYYYMMDD(UT)    V      err.
20080511.61557 16.436 0.013 Higashi-Hiroshima Observatory
20080513.61073 16.105 0.109 Higashi-Hiroshima Observatory
20080514.57342 14.434 0.007 Higashi-Hiroshima Observatory
20080515.62961 13.667 0.006 Higashi-Hiroshima Observatory

The light curve can be seen at:
http://kanatatmp.blogspot.com/search/label/CR%20Boo

Clear superhumps were detected last night, as can be seen in 
the above web page.  A superoutburst definitely started. 

The interval of the latest two superoutburst is about 45 days.

There is a precursor on 14 May, just before the onset of the 
current superoutburst.  It is proposed that the outburst-rebrightening 
behavior of AM CVn star is similar to those in WZ Sge stars 
(Kato et al., 2004, PASJ, 56, S89). On the other hand, a precursor 
of the superoutburst is considered to appear not in WZ Sge stars 
(Osaki & Meyer, 2003, A&A, 401, 325).

The discovery of the precursor in CR Boo may be a key fact for 
understanding the accretion disc physics.

Regards,
M. Uemura, M. Sasada, A. Arai, M. Yamanaka, 
on behalf of the KANATA team
Hiroshima University