A Reanalysis of the Composition of K2-106b: An Ultra-short-period Super-Mercury Candidate

We present a reanalysis of the K2-106 transiting planetary system, with focus on composition K2-106b, an ultra-short period, super-Mercury candidate. globally model existing photometric and radial velocity data derive mass radius for K2-106b $M_{p} = 8.53\pm1.02~M_{\oplus}$ $R_{p} 1.71^{+0.069}_{-0.057}~R_{\oplus}$, which leads to density $\rho_{p} 9.4^{+1.6}_{-1.5}$ $\rm g~cm^{-3}$, significantly lower value than previously reported in literature. use planet interior models that assume two-layer comprised liquid, pure Fe core iron-free, MgSiO_{3}$ mantle, we determine range fractions are consistent observed radius. high-resolution spectra host star Fe/Mg/Si abundances ([Fe/H]$=-0.03 \pm 0.01$, [Mg/H]$= 0.04 0.02$, [Si/H]$=0.03 0.06$) infer K2-106b. find although has high fraction ($44^{+12}_{-15}\%$) compared Earth ($33\%$), its is what expected assuming it reflects relative refractory star. therefore unlikely be super-Mercury, as been suggested previous