Photometric and spectroscopic study of a highly reddened type Ia supernova SN 2003hx in NGC 2076

Abstract

We present UBVRI CCD photometry and optical spectra of the type Ia supernova SN 2003hx which appeared in the galaxy NGC 2076, obtained till ~ 146 d after the epoch of B-band maximum. The supernova reached at maximum brightness in B band on JD 245 2893 ± 1.0 with an apparent magnitude of 14.92 ± 0.01 mag which was estimated by making template fits to the light curves. SN 2003hx is an example of a highly reddened supernova with E(B−V) = 0.56 ± 0.23. We estimate R_v= 1.97 ± 0.54 which indicates the small size of dust particles as compared to their galactic counterparts. The luminosity decline rate is Δm₁₅(B) = 1.17 ± 0.12 mag and the absolute B-band magnitude obtained from the luminosity versus decline rate relation (Phillips et al. 1999) is M^B_max=−19.20 ± 0.18 mag. The peak bolometric luminosity indicates that ~0.66 M☉ mass of ⁵⁶Ni was ejected by the supernova. The spectral evolution indicates the supernova to be a normal type Ia event.