We present GPI polarized intensity imagery of HD 100453 in Y- , J- , and K1 bands which reveals an inner gap ( 9 - 18 au ) , an outer disk ( 18 - 39 au ) with two prominent spiral arms , and two azimuthally-localized dark features also present in SPHERE total intensity images \citep wagner15 .
SED fitting further suggests the radial gap extends to 1 au .
The narrow , wedge-like shape of the dark features appears similar to predictions of shadows cast by a inner disk which is misaligned with respect to the outer disk .
Using the Monte Carlo radiative transfer code HOCHUNCK3D \citep whitney13 , we construct a model of the disk which allows us to determine its physical properties in more detail .
From the angular separation of the features we measure the difference in inclination between the disks ( 45 \degr ) , and their major axes , PA = 140 \degr east of north for the outer disk and 100 \degr for the inner disk .
We find an outer disk inclination of 25 \pm 10 \degr from face-on in broad agreement with the \citet wagner15 measurement of 34 \degr .
SPHERE data in J- and H-bands indicate a reddish disk which points to HD 100453 evolving into a young debris disk .