Optical light curves of SN 2012aa. The BVR_cI_c photometric measurements from ST, CT, and NTT are shown respectively with filled circles, squares, and triangles, while the CRTS measurements are open circles. The epochs are given with respect to the date of discovery. All the unfiltered CRTS magnitudes have been calibrated to the Johnson V-filter system using the local sequences. The solid line represents a third-order polynomial fit around the first broad peak observed in V, while the dotted lines represent third-order polynomial fits around the secondary peak in BVR_cI_c. The inset represents a comparison between the measurements from CRTS observations by using template subtraction (open stars) and flux subtraction (open circles). The solid line around the peak is again a third-order polynomial fit around the first peak using the measurements obtained from template subtraction. It is worth noting that the absolute-magnitude scale is corrected only for distance modulus (μ) to show the approximate luminosity. When determining a more accurate luminosity, reddening and the K-correction were also considered. See text for details.