2021/02/16 by Anirban Dutta, Avinash Singh, G. C. Anupama +2
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Carbon fibers #Composite number #Gamma-ray bursts and supernovae #Neutrino Physics Research #Physics #Supernova #Type (biology) #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stab481
15 pages, 13 figures, Accepted for publication in MNRAS
arxiv created 2021/02/16 · openalex publication_date 2021/02/18 · arxiv updated 2021/03/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
ABSTRACT We present the optical (UBVRI) and ultraviolet (Swift-Ultraviolet and Optical Telescope) photometry, and optical spectroscopy of Type Ia supernova SN 2017hpa. We study broad-band ultraviolet (UV)+optical light curves and low-resolution spectroscopy spanning from −13.8 to +108 d from the maximum light in B band. The photometric analysis indicates that SN 2017hpa is a normal Type Ia supernova with ΔmB(15) = 0.98 ± 0.16 mag and MB = −19.45 ± 0.15 mag at a distance modulus of μ = 34.08 ± 0.09 mag. The (uvw1 − uvv) colour evolution shows that SN 2017hpa falls in the near-UV (NUV)-blue group. The (B − V) colour at maximum is bluer in comparison to normal Type Ia supernovae. Spectroscopic analysis shows that the Si ii λ6355 Å absorption feature evolves rapidly with a velocity gradient, v=128± 7 km s−1 d−1. The pre-maximum phase spectra show prominent C ii λ6580 Å absorption feature. The C ii 6580 Å line velocity measured from the observed spectra is lower than the velocity of Si ii λ6355 Å, which could be due to a line-of-sight effect. The synthetic spectral fits to the pre-maximum spectra using syn++ indicate the presence of a high-velocity component in the Si ii absorption, in addition to a photospheric component. Fitting the observed spectrum with the spectral synthesis code tardis, the mass of unburned C in the ejecta is estimated to be ∼0.019 M⊙. The peak bolometric luminosity is L^\rm bol_\rm peak = 1.43× 1043 erg s−1. The radiation diffusion model fit to the bolometric light curve indicates 0.61 ± 0.02 M⊙ of 56Ni is synthesized in the explosion.