Photometric and spectroscopic observations of a slowly declining, luminous Type Ia supernova (SN Ia) SN 2011hr in the starburst galaxy NGC 2691 are presented. SN?2011hr is found to peak at , with a postmaximum decline rate Δm15(B) = 0.92?±?0.03 mag. From the maximum-light bolometric luminosity, , we estimate the mass of synthesized 56Ni in SN?2011hr to be . SN 2011hr appears more luminous than SN 1991T at around maximum light, and the absorption features from its intermediate-mass elements (IMEs) are noticeably weaker than those of the latter at similar phases. Spectral modeling suggests that SN 2011hr has IMEs of ~0.07 in the outer ejecta, which is much lower than the typical value of normal SNe Ia (i.e., 0.3–0.4 ) and is also lower than the value of SN 1991T (i.e., ~0.18 ). These results indicate that SN?2011hr may arise from a Chandrasekhar-mass white dwarf progenitor that experienced a more efficient burning process in the explosion. Nevertheless, it is still possible that SN?2011hr may serve as a transitional object connecting the SN 1991T-like SNe Ia with a superluminous subclass like SN 2007if given that the latter also shows very weak IMEs at all phases.
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