  Using a Bayesian approach, we combine measurements of neutron star
macroscopic observables obtained by astrophysical and gravitational
observations, to derive joint constraints on the equation of state (EoS) of
matter at supranuclear density. In our analysis we use two sets of data: (i)
the masses and tidal deformabilities measured in the binary neutron star event
GW170817, detected by LIGO and Virgo; (ii) the masses and stellar radii
measured from observations of nuclear bursts in accreting low-mass X-ray
binaries. Using two different parametrizations of the equation of state, we
compute the posteriorprobability distributions of the EoS parameters, using
which we infer the posterior distribution for the radius and the mass of the
two neutron stars of GW170817. The constraints we set on the radii are tighter
than previous bounds.
