We present the first polarimetric detection of the inner disk component around the pre-main sequence B9.5 star HD 141569A .
Gemini Planet Imager H -band ( 1.65 \mu m ) polarimetric differential imaging reveals the highest signal-to-noise ratio detection of this ring yet attained and traces structure inwards to 0 \farcs 25 ( 28 AU at a distance of 111 pc ) .
The radial polarized intensity image shows the east side of the disk , peaking in intensity at 0 \farcs 40 ( 44 AU ) and extending out to 0 \farcs 9 ( 100 AU ) .
There is a spiral arm-like enhancement to the south , reminiscent of the known spiral structures on the outer rings of the disk .
The location of the spiral arm is coincident with ^ { 12 } CO J=3–2 emission detected by ALMA , and hints at a dynamically active inner circumstellar region .
Our observations also show a portion of the middle dusty ring at \sim 220 AU known from previous observations of this system .
We fit the polarized H -band emission with a continuum radiative transfer Mie model .
Our best-fit model favors an optically thin disk with a minimum dust grain size close to the blow-out size for this system : evidence of on-going dust production in the inner reaches of the disk .
The thermal emission from this model accounts for virtually all of the far-infrared and millimeter flux from the entire HD 141569A disk , in agreement with the lack of ALMA continuum and CO emission beyond \sim 100 AU .
A remaining 8–30 \micron thermal excess a factor of \sim 2 above our model argues for a yet-unresolved warm innermost 5–15 AU component of the disk .