BVRI Photometry of SN 2013ej in M74

摘要

I present BVRI photometry of the type IIP supernova 2013ej in M74 from 1 to 179 days after its discovery. These photometric measurements and spectroscopic data from the literature are combined via the expanding photosphere method to estimate the distance to the event, which is consistent with that derived by other methods. After correcting for extinction and adopting a distance modulus of(m-M) = 29.80 mag. to M74,1 derive absolute magnitudes M_R = -17.36, M_y=-17.47, M_R = -17.64, and M_t = -17.71. The differences between visual measurements and CCD V-band measurements of SN 2013ej are similar to those determined for type la supernovae and ordinary stars.