The light curve of the 1998 outburst of V2487 Ophiuchi ( Nova Oph 1998 ) shows a very rapid decline ( t _ { 3 } \sim 9 day ) and a mid-plateau phase from 10 to 30 days after the optical maximum , which are characteristics common to the U Sco subclass of the recurrent novae .
We have numerically reproduced light curves of the 1998 outburst based on a thermonuclear runaway model with optically thick winds .
The results show that the mass of the white dwarf ( WD ) is as massive as 1.35 \pm 0.01 M _ { \odot } ; the envelope mass of the WD at the optical maximum is \sim 6 \times 10 ^ { -6 } M _ { \odot } ; the hydrogen content of the WD envelope is as low as X \sim 0.1 by mass weight .
The mass transfer rate in quiescence is roughly estimated to be \sim 1.5 \times 10 ^ { -7 } M _ { \odot } yr ^ { -1 } and , therefore , that the recurrence period of nova outbursts is about 40 yr .
Since the WD mass may be now growing at a rate of \sim 2 \times 10 ^ { -8 } M _ { \odot } yr ^ { -1 } , V2487 Oph is a strong candidate for a progenitor of a Type Ia supernova .