We compare radii based on Gaia parallaxes to asteroseismic scaling relation-based radii of \sim 300 dwarfs & subgiants and \sim 3600 first-ascent giants from the Kepler mission .
Systematics due to temperature , bolometric correction , extinction , asteroseismic radius , and the spatially-correlated Gaia parallax zero-point , contribute to a 2 \% systematic uncertainty on the Gaia -asteroseismic radius agreement .
We find that dwarf and giant scaling radii are on a parallactic scale at the -2.1 \% \pm 0.5 \% { ( rand . ) } \pm 2.0 \% { ( syst . ) } level ( dwarfs ) and +1.7 \% \pm 0.3 \% { ( rand . ) } \pm 2.0 \% { ( syst . ) } level ( giants ) , supporting the accuracy and precision of scaling relations in this domain .
In total , the 2 \% agreement that we find holds for stars spanning radii between 0.8 R _ { \odot } and 30 R _ { \odot } .
We do , however , see evidence for relative errors in scaling radii between dwarfs and giants at the 4 \% \pm 0.6 \% level , and find evidence of departures from simple scaling relations for radii above 30 R _ { \odot } .
Asteroseismic masses for very metal-poor stars are still overestimated relative to astrophysical priors , but at a reduced level .
We see no trend with metallicity in radius agreement for stars with -0.5 < [ Fe/H ] < +0.5 .
We quantify the spatially-correlated parallax errors in the Kepler field , which globally agree with the Gaia team ’ s published covariance model .
We provide Gaia radii , corrected for extinction and the Gaia parallax zero-point for our full sample of \sim 3900 stars , including dwarfs , subgiants , and first-ascent giants .