We present extensively dense observations of the super-Chandrasekhar supernova ( SC SN ) candidate SN 2012dn from -11 to +140 days after the date of its B -band maximum in the optical and near-infrared ( NIR ) wavelengths conducted through the OISTER ToO program .
The NIR light curves and color evolutions up to 35 days after the B -band maximum provided an excellent match with those of another SC SN 2009dc , providing a further support to the nature of SN 2012dn as a SC SN .
We found that SN 2012dn exhibited strong excesses in the NIR wavelengths from 30 days after the B -band maximum .
The H and K _ { s } -band light curves exhibited much later maximum dates at 40 and 70 days after the B -band maximum , respectively , compared with those of normal SNe Ia .
The H and K _ { s } -band light curves subtracted by those of SN 2009dc displayed plateaued evolutions , indicating a NIR echo from the surrounding dust .
The distance to the inner boundary of the dust shell is limited to be 4.8 - 6.4 \times 10 ^ { -2 } pc .
No emission lines were found in its early phase spectrum , suggesting that the ejecta-CSM interaction could not occur .
On the other hand , we found no signature that strongly supports the scenario of dust formation .
The mass loss rate of the pre-explosion system is estimated to be 10 ^ { -6 } -10 ^ { -5 } M _ { \odot } yr ^ { -1 } , assuming that the wind velocity of the system is 10 - 100 km s ^ { -1 } , which suggests that the progenitor of SN 2012dn could be a recurrent nova system .
We conclude that the progenitor of this SC SN could be explained by the single-degenerate scenario .