摘要：Aims. We present and study the spectroscopic and photometric evolution
of the type Ia supernova (SN Ia) 2010ev.
Methods. We obtain and analyze multiband optical light curves and
optical/near-infrared spectroscopy at low and medium resolution spanning −7 days to +300 days from the B-band maximum.
Results. A photometric analysis shows that SN 2010ev is a SN Ia of
normal brightness with a light-curve shape of Δm15(B) = 1.12 ± 0.02
and a stretch s = 0.94 ±
0.01 suffering significant reddening. From photometric and
spectroscopic analysis, we deduce a color excess of E(B − V) =
0.25 ± 0.05 and a reddening law of Rv = 1.54 ±
0.65. Spectroscopically, SN 2010ev belongs to the broad-line SN Ia
group, showing stronger than average Si
iiλ6355 absorption features. We also find that SN
2010ev is a high velocity gradient SN with v̇Si = 164 ± 7 km s-1 d-1. The photometric and spectral
comparison with other supernovae shows that SN 2010ev has similar colors and velocities to
SN 2002bo and SN 2002dj. The analysis of the nebular spectra indicates that the
[Fe ii]λ7155 and [Ni ii]λ7378 lines are redshifted,
as expected for a high velocity gradient supernova. All these common intrinsic and
extrinsic properties of the high velocity gradient (HVG) group are different from the low
velocity gradient (LVG) normal SN Ia population and suggest significant variety in SN Ia
explosions.
关键词：supernovae: general;supernovae: individual: SN 2010ev
