Based on regularities in rotational splittings, we seek possible multiplets for the observed frequencies of CoRoT 102749568. Twenty-one sets of multiplets are identified, including four sets of multiplets with $l=1$, nine sets of multiplets with $l=2$, and eight sets of multiplets with $l=3$. In particular, there are three complete triplets ($f_{ 10}$, $f_{ 12}$, $f_{ 14}$), ($f_{ 31}$, $f_{ 34}$, $f_{ 35}$), and ($f_{ 41}$, $f_{ 43}$, $f_{ 44}$). The rotational period of CoRoT 102749568 is estimated to be $1.34^{ +0.04}_{ -0.05}$ days. When doing model fittings, three $l=1$ modes ($f_{ 12}$, $f_{ 34}$, and $f_{ 43}$) and the radial first overtone $f_{ 13}$ are used. Our results shows that the three nonradial modes ($f_{ 12}$, $f_{ 34}$, and $f_{ 43}$) are mixed modes, which mainly provide constraints on the helium core. The radial first overtone $f_{ 13}$ mainly provides constraint on the stellar envelope. Hence the size of the helium core of CoRoT 102749568 is determined to be $M_{ \rm He}$ = 0.148 $\pm$ 0.003 $M_{ \odot}$ and $R_{ \rm He}$ = 0.0581 $\pm$ 0.0007 $R_{ \odot}$. The fundamental parameters of CoRoT 102749568 are determined to be $M$ = 1.54 $\pm$ 0.03 $M_{ \odot}$, $Z=$ 0.006, $f_{ \rm ov}$ = 0.004 $\pm$ 0.002, $\log g$ = 3.696 $\pm$ 0.003, $T_{ \rm eff}$ = 6886 $\pm$ 70 K, $R$ = 2.916 $\pm$ 0.039 $R_{ \odot}$, and $L$ = 17.12 $\pm$ 1.13 $L_{ \odot}$.
Categories: astro-ph.SR