■ [Extragalactic nova] M31 2011-01a : observation start
We started observations of extragalactic nova M31 2011-01a since Jan. 9. We roughly measured the apparent peak magnitude of 15.3 mag in V-band. This indicates that this nova is one of the very bright nova. It roughly takes 10 days to decrease by 2 magnitudes. Thus, this nova is classified into very fast nova. This very fast decline is consistent with high peak luminosity. We will continue the observations of this nova.