Asteroseismology of the DAV Star L19-2

L19-2 is a DAV star, which has been intermittently observed from 1976 to 2013. Five independent pulsation modes of 350\,s, 192\,s, 143\,s, 118\,s, and 113\,s are identified. The five can be used constrain the fitting models. rates period change obtained through O-C method for 192\,s 113\,s, study evolution effect stars. Using \texttt{WDEC} (2018 version), large sample star models evolved. theoretical calculated fit modes. After fine model fittings, we obtain an optimal with absolute difference $\Phi$ = 0.06\,s. By parameterizing core oxygen profile, version) procedure greatly reduce error asteroseismological model. According our model, distance luminosity only 1\% different that reported by Gaia Data Release 2. massive hot relatively thick H atmosphere He layer. stellar parameters little modifications previous work. Our central abundance. abundance strongly correlated physical process evolution. A lot work on white dwarfs have opportunity explore progenitor