  We constrain the explosion and circumstellar properties at the 2012b event of
SN 2009ip based on its late-phase bolometric light curve recently reported. The
explosion energy and ejected mass at the 2012b event are estimated as 0.01 Msun
and 2e49 erg, respectively. The circumstellar medium is assumed to have two
components: an inner shell and an outer wind. The inner shell which is likely
created at the 2012a event has 0.2 Msun. The outer wind is created by the wind
mass loss before the 2012a mass ejection, and the progenitor is estimated to
have had the mass-loss rate about 0.1 Msun/yr with the wind velocity 550 km/s
before the 2012a event. The estimated explosion energy and ejected mass
indicate that the 2012b event is not caused by a regular supernova.
