Determine whether WISPIT 2 b hosts a circumplanetary disk

Determine whether a circumplanetary disk is present around the actively accreting protoplanet WISPIT 2 b by obtaining mid-infrared observations capable of distinguishing planetary emission from circumplanetary-disk emission.

Background

The authors model a possible circumplanetary disk by adding a second blackbody component to atmospheric models and analyze GRAVITY+ visibilities to constrain its spatial extent. The data provide an upper limit on the size of a bright disk, but the constraints are substantially weaker for a faint disk contributing only a small fraction of the K-band flux.

The available observations do not establish whether WISPIT 2 b possesses circumplanetary material. The authors argue that mid-infrared observations are needed because circumplanetary-disk emission should dominate beyond approximately 5 micrometres, while molecular and silicate features can also distinguish atmospheric emission from disk emission.

References

While we were unable to confidently distinguish between models with and without CPD, we were able to constrain the effective temperature of WISPIT 2 b to $\sim900$ to 1300~K.

— A first look at the protoplanet WISPIT 2 b with VLTI/GRAVITY+  (2610.21629 - Collaboration et al., 15 Oct 2026) in Section 4, “Conclusions”