The key impact of the host star’s rotational history on the evolution of TOI-849b

TOI-849b is one of the few planets populating hot-Neptune desert and it densest Neptune-sized discovered so far. Its extraordinary proximity to host star, together with absence a massive H/He envelope on top $40.8 ~M_{\oplus}$ rocky core calls into question role played by star in evolution system. We aim study impact star's rotational history TOI-849b, focussing planetary migration due dynamical tides dissipated stellar convective high-energy emission. Rotating models TOI-849 are coupled our orbital code orbit. The atmosphere studied means JADE code, which uses realistic XUV-fluxes provided rotating models. Assuming that planet was at its present day position ($a=0.01598 \rm AU$) protoplanetary disc dispersal, mass $40.8~ M_{\oplus}$, considering broad range initial surface rotation rates ($\Omega_{\rm in}$) $ [3.2, 18]~ \Omega_{\odot}$, we find only for $\Omega_{\rm in} \leq 5 \Omega_{\odot}$ do reproduce current planet, given in}$ larger than $5 orbit efficiently deflected tides. tested increasing efficiency tides, finding higher ($1~M_{\rm Jup}$) does not change results reported above. Based these computed atmospheres large masses above $40.8~M_{\oplus}$, strong XUV-flux received able remove entirety within first 50 Myr, even if formed as Jupiter-mass planet.