Asteroseismology of the ZZ Ceti star KUV 11370+4222

KUV 11370+4222 is a ZZ Ceti star discovered in 1996, which has not been observed since then. We performed observations for KUV 11370+4222 in 2010 January. From the Fourier transform spectrum of the light curves, 10 independent modes are detected. We searched for the best-fitting model by using the observed periods to match the model periods and obtained it with the total mass of 0.625 M, the effective temperature of 10 950 K, and the helium mass fraction and hydrogen mass fraction of 10−2.2 and 10−4.0, respectively. We have found a triplet of frequency split by rotation, which are l = 1 modes. Using the frequency shifts, we estimate a rotation period of 5.56 ± 0.08 h. Besides it, another l = 1 mode is identified. The other observed periods are identified as l = 2 modes. At last we investigated the property of the mode trapping.