| Summary: | SDSS J111215.82+111745.0 is the second pulsating extremely low-mass white dwarf discovered. Two short-period pulsations, 107.56 and 134.275 s, were detected on this star, which would be the first observed pressure mode ( p -mode) pulsations observed on a white dwarf. While the two potential p -modes have yet to be confirmed, they make SDSS J111215.82+111745.0 an interesting object. In this work, we analyzed the whole set of seven periods observed on SDSS J111215.82+111745.0. We adopt three independent period-spacing tests to reveal a roughly 93.4 s mean period spacing of ℓ = 1 g -modes, which gives added credence to the ℓ = 1 identifications. Then we perform asteroseismic modeling for this star, in which the H chemical profile is taken as a variable. The stellar parameters M = 0.1650 ± 0.0137 M _☉ and T _eff = 9750 ± 560 K are determined from the best-fit model, and the H/He chemical profiles are also defined. The two suspected p -modes are also well represented in the best-fit model, and both the stellar parameters and the pulsation frequencies are in good agreement with the values derived from spectroscopy.
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