Abstract:
We present results based on a well-sampled optical (
UBVRI
) and ultraviolet (
Swift
/UVOT)
imaging, and low-resolution optical spectroscopic follow-up observations of the nearby Type Ic
supernova (SN) ASASSN-16fp (SN 2016coi). The SN was monitored during the photospheric
phase (
−
10 to
+
33 d with respect to the
B
-band maximum light). The rise to maximum light
and early post-maximum decline of the light curves are slow. The peak absolute magnitude
(
M
V
=−
17.7
±
0.2 mag) of ASASSN-16fp is comparable with broad-lined Ic SN 2002ap,
SN 2012ap and transitional Ic SN 2004aw but considerably fainter than the gamma-ray
burst/X-ray flash associated SNe (e.g. SN 1998bw, 2006aj). Similar to the light curve, the
spectral evolution is also slow. ASASSN-16fp shows distinct photospheric phase spectral
lines along with the C
II
features. The expansion velocity of the ejecta near maximum light
reached
∼
16 000 km s
−
1
and settled to
∼
8000 km s
−
1
,
∼
1 month post-maximum. Analytical
modelling of the quasi-bolometric light curve of ASASSN-16fp suggests that
∼
0.1 M
56
Ni
mass was synthesized in the explosion, with a kinetic energy of 6.9
+
1
.
5
−
1
.
3
×
10
51
erg and total
ejected mass of
∼
4.5
±
0.3 M
.
