(Proposal ID) S16B-016

(PI) Uyama, Taichi

(Proposal Title)
Search for Exoplanet Accretion Signatures in Transitional Disks II

(Abstract)
Disk studies have reported a dozen of protoplanetary disks having small inner 
gap (transitional disks) around Young Stellar Objects (YSOs). This structure 
is thought to be a signature of exoplanet but detection reports of planets 
within the gaps are still controversial. This is because most of the YSOs are 
too far (typically 140pc from the Sun) for classical Adaptive Optics (AO) to 
detect any possible exoplanets in the gaps. Here we propose integral field 
spectroscopy of Young Stellar Objects with Keck/OSIRIS combined with Adaptive 
Optics to search for any actively mass-accreting planets. This method has 
synergy extreme AO such as SCExAO to solve degeneracy of accretion luminosity. 
The Pabeta line emission in the Jn2 band (1.228-1.289 mum) is used for the 
accretion signature.  By measuring the mass accretion onto a companion, ~100 
min observation will be able to detect very small exoplanets as ~0.5 M_J 
around YSOs. If we successfully detect any exoplanets with active mass 
accretion, we can demonstrate the relationship between the planet formation 
and the transitional disk as LkCa 15 b. Even if null-detection, we can set a 
better constraint of the mass of potential planet(s).