Optical $UBVRI$ photometry and medium resolution spectroscopy of the type Ib supernova SN 2009jf, during the period $sim -15$ to +250days with respect to the $B$ maximum are reported. The light curves are broad, with an extremely slow decline. The ea
rly post-maximum decline rate in the $V$ band is similar to SN 2008D, however, the late phase decline rate is slower than other studied type Ib supernovae. With an absolute magnitude of $M_{V} = -17.96pm0.19$ magnitude at peak, SN 2009jf is a normally bright supernova. The peak bolometric luminosity and the energy deposition rate via $^{56}$Ni $rightarrow$ $^{56}$Co chain indicate that $sim {0.17}^{+0.03}_{-0.03}$ M$_{odot}$ of $^{56}$Ni was ejected during the explosion. He,I 5876 AA line is clearly identified in the first spectrum of day $sim -15$, at a velocity of $sim 16000$ km sec$^{-1}$. The [O,I] 6300-6364 AA line seen in the nebular spectrum has a multi-peaked and asymmetric emission profile, with the blue peak being stronger. The estimated flux in this line implies $ga 1.34$ M$_odot$ oxygen was ejected. The slow evolution of the light curves of SN 2009jf indicates the presence of a massive ejecta. The high expansion velocity in the early phase and broader emission lines during the nebular phase suggest it to be an explosion with a large kinetic energy. A simple qualitative estimate leads to the ejecta mass of M$_{rm ej} = 4-9$ M$_odot$, and kinetic energy E$_{rm K} = 3-8 times 10^{51}$ erg. The ejected mass estimate is indicative of an initial main-sequence mass of $ga 20- 25$ M$_odot$.
Photometric and spectral evolution of the Type Ic supernova SN 2007ru until around 210 days after maximum are presented. The spectra show broad spectral features due to very high expansion velocity, normally seen in hypernovae. The photospheric veloc
ity is higher than other normal Type Ic supernovae. It is lower than SN 1998bw at $sim$ 8 days after the explosion, but is comparable at later epochs. The light curve evolution of SN 2007ru indicates a fast rise time of 8$pm$3 days to $B$ band maximum and post-maximum decline more rapid than other broad-line Type Ic supernovae. With an absolute $V$ magnitude of -19.06, SN 2007ru is comparable in brightness with SN 1998bw and lies at the brighter end of the observed Type Ic supernovae. The ejected mass of Nifs is estimated to be $sim0.4Msun$. The fast rise and decline of the light curve and the high expansion velocity suggest that SN 2007ru is an explosion with a high kinetic energy/ejecta mass ratio ($E_{rm K}/M_{rm {ej}}$). This adds to the diversity of Type Ic supernovae. Although the early phase spectra are most similar to those of broad-line SN 2003jd, the [OI] line profile in the nebular spectrum of SN 2007ru shows the singly-peaked profile, in contrast to the doubly-peaked profile in SN 2003jd. The singly-peaked profile, together with the high luminosity and the high expansion velocity, may suggest that SN 2007ru could be an aspherical explosion viewed from the polar direction. Estimated oxygen abundance 12 + log(O/H) of $sim$8.8 indicates that SN 2007ru occurred in a region with nearly solar metallicity.
$UBVRI$ photometry and medium resolution optical spectroscopy of peculiar Type Ia supernova SN 2005hk are presented and analysed, covering the pre-maximum phase to around 400 days after explosion. The supernova is found to be underluminous compared t
o normal Type Ia supernovae. The photometric and spectroscopic evolution of SN 2005hk is remarkably similar to the peculiar Type Ia event SN 2002cx. The expansion velocity of the supernova ejecta is found to be lower than normal Type Ia events. The spectra obtained $gsim 200$ days since explosion do not show the presence of forbidden [ion{Fe}{ii}], [ion{Fe}{iii}] and [ion{Co}{iii}] lines, but are dominated by narrow, permitted ion{Fe}{ii}, NIR ion{Ca}{ii} and ion{Na}{i} lines with P-Cygni profiles. Thermonuclear explosion model with Chandrasekhar mass ejecta and a kinetic energy smaller ($KE = 0.3 times 10^{51} {rm ergs}$) than that of canonical Type Ia supernovae is found to well explain the observed bolometric light curve. The mass of Nifs synthesized in this explosion is $0.18 Msun$. The early spectra are successfully modeled with this less energetic model with some modifications of the abundance distribution. The late spectrum is explained as a combination of a photospheric component and a nebular component.
