  Extensive optical and ultraviolet (UV) observations of the type Ia supernova
(SN Ia) 2012fr are presented in this paper. It has a relatively high
luminosity, with an absolute $B$-band peak magnitude of about $-19.5$ mag and a
smaller post-maximum decline rate than normal SNe Ia [e.g., $\Delta m
_{15}$($B$) $= 0.85 \pm 0.05$ mag]. Based on the UV and optical light curves,
we derived that a $^{56}$Ni mass of about 0.88 solar masses was synthesized in
the explosion. The earlier spectra are characterized by noticeable
high-velocity features of \ion{Si}{2} $\lambda$6355 and \ion{Ca}{2} with
velocities in the range of $\sim22,000$--$25,000$ km s$^{-1}$. At around the
maximum light, these spectral features are dominated by the photospheric
components which are noticeably narrower than normal SNe Ia. The post-maximum
velocity of the photosphere remains almost constant at $\sim$12,000 km s$^{-1}$
for about one month, reminiscent of the behavior of some luminous SNe Ia like
SN 1991T. We propose that SN 2012fr may represent a subset of the SN 1991T-like
SNe Ia viewed in a direction with a clumpy or shell-like structure of ejecta,
in terms of a significant level of polarization reported in Maund et al.
(2013).
