Revealing a third protoplanet in the PDS 70 system with VLTI/GRAVITY+

PDS 70 b and c, located within a gap in the PDS 70 protoplanetary disk, are two of the most well-characterised protoplanets. Recent JWST observations have suggested the presence of a third inner companion in this system, referred to as PDS 70 d. However, since d is located close to the outer edge of the inner disk it is possible that it is not a planet and instead a mischaracterised disk feature. We use VLTI/GRAVITY+ to search for PDS 70 d and determine whether it is a planet or a part of the protoplanetary disk. If PDS 70 d is indeed a planet we should see a K-band thermal emission spectrum, as well as visibility data that indicates a point-like source. Additionally these observations can provide astrometry for the proposed planet, allowing us to constrain its orbit. This data currently provides our best opportunity to confirm the presence of a third, inner planet in the PDS 70 system.