  Recent progresses in lattice studies of heavy quark and quarkonium at
non-zero temperature are discussed. Formulating a tail of spectral functions as
a transport coefficient allows lattice determination of momentum diffusion
coefficient ($\kappa$) for charm quark in the heavy quark mass limit and
lattice determination of heavy quark/heavy anti-quark chemical equilibration
rate in NRQCD. Quenched lattice study on a large volume gives $\kappa/T^3 = 1.8
\cdots 3.4$ in the continuum limit. A recent study with $N_f = 2+1$
configurations estimates the charmonium chemical equilibration rate
$\Gamma_{\rm chem}$. At $T = 400$ MeV with $M \sim 1.5$ GeV, $\Gamma_{\rm
chem}^{-1} \sim 150$ fm/c. Earlier results from the two studies (with different
lattice setups and with different Bayesian priors) which calculate bottomonium
correlators using NRQCD and employ Bayesian method to calculate spectral
functions are summarized: $\Upsilon (1S)$ survives upto $T \sim 1.9 T_c$ and
excited states of $\Upsilon$ are sequentially suppressed. The spectral
functions of $\chi_{b1}$ channel shows a Bayesian prior dependence of its
thermal behavior: the $\chi_{b1}$ spectral function with MEM prior shows
melting above $T_c$ but that with a new Bayesian prior hints survival of
$\chi_{b1}$ upto $\sim 1.6 T_c$. Preliminary results from the efforts to
understand the difference in the behavior of $\chi_{b1}$ spectral function is
given.
