We present extensive ground-based and Hubble~ { } Space~ { } Telescope ( HST ) photometry of the highly reddened , very nearby type Ia supernova ( SN Ia ) 2014J in M82 , covering the phases from 9 days before to about 900 days after the B -band maximum .
SN 2014J is similar to other normal SNe Ia near the maximum light , but it shows flux excess in the B band in the early nebular phase .
This excess flux emission can be due to light scattering by some structures of circumstellar materials located at a few 10 ^ { 17 } cm , consistent with a single degenerate progenitor system or a double degenerate progenitor system with mass outflows in the final evolution or magnetically driven winds around the binary system .
At t \sim +300 to \sim +500 days past the B -band maximum , the light curve of SN 2014J shows a faster decline relative to the ^ { 56 } Ni decay .
Such a feature can be attributed to the significant weakening of the emission features around [ Fe III ] \lambda 4700 and [ Fe II ] \lambda 5200 rather than the positron escape as previously suggested .
Analysis of the HST images taken at t > 600 days confirms that the luminosity of SN 2014J maintains a flat evolution at the very late phase .
Fitting the late-time pseudo-bolometric light curve with radioactive decay of ^ { 56 } Ni , ^ { 57 } Ni and ^ { 55 } Fe isotopes , we obtain the mass ratio ^ { 57 } Ni/ ^ { 56 } Ni as 0.035 \pm 0.011 , which is consistent with the corresponding value predicted from the 2D and 3D delayed-detonation models .
Combined with early-time analysis , we propose that delayed-detonation through single degenerate scenario is most likely favored for SN 2014J .