We present the first light curve analysis of Population II novae that appeared in M31 globular clusters .
Our light curve models , based on the optically thick wind theory , reproduce well both the X-ray turn-on and turnoff times with the white dwarf ( WD ) mass of about 1.2 M _ { \odot } for M31N 2007-06b in Bol 111 and about 1.37 M _ { \odot } for M31N 2010-10f in Bol 126 .
The transient supersoft X-ray source CXO J004345 in Bol 194 is highly likely a nova remnant of 1.2 – 1.3 M _ { \odot } WD .
These WD masses are quite consistent with the temperatures deduced from X-ray spectra .
We also present the dependence of nova light curves on the metallicity in the range from [ Fe/H ] =0.4 to -2.7 .
Whereas strong optically thick winds are accelerated in Galactic disk novae owing to a large Fe opacity peak , only weak winds occur in Population II novae with low Fe abundance .
Thus , nova light curves are systematically slow in low Fe environment .
For an extremely low Fe abundance normal nova outbursts may not occur unless the WD is very massive .
We encourage V or y filter observation rather than R as well as high cadence X-ray monitorings to open quantitative studies of extragalactic novae .