The Giant Accreting Protoplanet Survey (GAPlanetS) — Final Results and Next Steps

We are entering an exciting era where it is possible to directly observe the assembly of giant planets, both through detection and characterization of forming protoplanets at optical and infrared wavelengths and through resolved imaging of their circumplanetary environments at millimeter wavelengths. We present final results from the Giant Accreting Protoplanet Survey (GAPlanetS), a five year visible light high contrast imaging campaign targeting the fifteen brightest Southern Hemisphere transitional disks. The GAPlanetS survey leveraged the reduced contrast between accreting protoplanets and their host stars at the wavelength of the H-alpha accretion emission line to detect three accreting companions at just 0.1-0.25 arcsec separation from their host stars. These measurements confirmed the existence of the companions inside the cleared gaps and cavities of their host disks, and enabled estimates of their mass accretion rates. The final survey results include new uniform analyses of the HD142527B stellar companion and the planetary companions LkCa 15b and PDS 70b, as well as limits on accreting protoplanets in the remaining systems.