Near-Infrared Imaging Polarimetry of LkCa 15: A Possible Warped Inner Disk

TL;DR

This study uses high-contrast near-infrared imaging to reveal a warped inner disk and a large gap in the transitional disk around LkCa 15, suggesting the presence of multiple planets.

Contribution

First high-resolution polarized imaging showing a warped inner disk and a confirmed large gap in LkCa 15's disk.

Findings

Resolved a gap of <~27 AU at ~48 AU from the star

Confirmed a misaligned, possibly warped, inner disk

Suggests existence of multiple planets with mass <~1 Mjup

Abstract

We present high-contrast H-band polarized intensity images of the transitional disk around the young solar-like star LkCa 15. By utilizing Subaru/HiCIAO for polarimetric differential imaging, both the angular resolution and the inner working angle reach 0.07" and r=0.1", respectively. We obtained a clearly resolved gap (width <~ 27 AU) at ~ 48 AU from the central star. This gap is consistent with images reported in previous studies. We also confirmed the existence of a bright inner disk with a misaligned position angle of 13+/-4 degree with respect to that of the outer disk, i.e., the inner disk is possibly warped. The large gap and the warped inner disk both point to the existence of a multiple planetary system with a mass of <~1Mjup.