Asteroseismology is a unique tool to explore the internal structure of stars through both observational and theoretical research . The internal structure of pulsating hydrogen shell white dwarfs ( ZZ Ceti stars ) detected by asteroseismology is regarded as the representative of all DA white dwarfs . Observations for KUV 08368+4026 , which locates in the middle of the ZZ Ceti instability strip , have been carried out in 1999 and from 2009 to 2012 with either single-site runs or multisite campaigns . Time-series photometric data of about 300 hours were collected in total . Through data reduction and analysis , 30 frequencies were extracted , including four triplets , two doublets , one single mode and further signals . The independent modes are identified as either l=1 or l=2 modes . Hence , a rotation period of 5.52 \pm 0.22 days was deduced from the period spacing in the multiplets . Theoretical static models were built and a best fit model for KUV 08368+4026 was obtained with 0.692 \pm 0.002 solar mass , ( 2.92 \pm 0.02 ) \times 10 ^ { -3 } solar luminosity and the hydrogen mass fraction of 10 ^ { -4 } stellar mass .