SN2017hpa carbon-rich type Ia LCs and sp.

The light curves indicate that SN 2017hpa is a normal SN Ia with an absolute peak magnitude of M_max_^B^~-19.12+/-0.11mag and a postpeak decline rate {Delta}m_15_(B)=1.02+/-0.07mag. According to the quasi-bolometric light curve, we derive a peak luminosity of 1.25x10^43^erg/s and a ^56^Ni mass of 0.63+/-0.02M_{sun}_.

The spectral evolution of SN 2017hpa is similar to that of normal Ia supernovae (SNe Ia), while it exhibits an unusually rapid velocity evolution resembling that of SN 1991bg-like SNe Ia or the high- velocity subclass of SNe Ia, with a postpeak velocity gradient of ~130+/-7km/s/d. Moreover, its early spectra (t{<}-7.9d) show a prominent CII{lambda}6580 absorption feature, which disappeared in near-maximum-light spectra but reemerged at phases from t~+8.7d to t~+11.7d after maximum light.