  G 207-9 and LP 133-144 are two rarely observed ZZ Ceti stars located in the
middle and close to the blue edge of the ZZ Ceti instability domain,
respectively. We aimed to observe them at least during one observing season at
Konkoly Observatory with the purpose of extending the list of known pulsation
modes for asteroseismic investigations and detect any significant changes in
their pulsational behaviour. We determined five and three new normal modes of G
207-9 and LP 133-144, respectively. In LP 133-144, our frequency analysis also
revealed that at least at three modes there are actually triplets with
frequency separations of ~4 microHz. The rotational period of LP 133-144 based
on the triplets is ~42 h. The preliminary asteroseismic fits of G 207-9 predict
Teff=12 000 or 12 400 K and M*=0.855-0.870 MSun values for the effective
temperature and mass of the star, depending on the assumptions on the spherical
degree (l) values of the modes. These results are in agreement with the
spectroscopic determinations. In the case of LP 133-144, the best-fitting
models prefer Teff=11 800 K in effective temperature and M*>=0.71 MSun stellar
masses, which are more than 0.1 MSun larger than the spectroscopic value.
