Comparison of the Galactocentric distances computed using Gaia DR2 parallaxes only, or combining them with a geometrical distance prior (Bailer-Jones et al. 2018). Galactocentric distances derived from near-infrared photometry (Inno et al. 2013; Genovali et al. 2014) and their associated error bars are shown in red. For comparison purposes, all the distances have been computed assuming that the Sun is located at 7.94 kpc from the Galactic center (Matsunaga et al. 2013).