  We present $H$-band scattered light imaging of a bright debris disk around
the A0 star HD 36546 obtained from the Subaru Coronagraphic Extreme Adaptive
Optics (SCExAO) system with data recorded by the HiCIAO camera using the vector
vortex coronagraph. SCExAO traces the disk from $r$ $\sim$ 0.3" to $r$ $\sim$
1" (34--114 au). The disk is oriented in a near east-west direction (PA $\sim$
75$^{o}$), is inclined by $i$ $\sim$ 70--75$^{o}$ and is strongly
forward-scattering ($g$ $>$ 0.5). It is an extended disk rather than a sharp
ring; a second, diffuse dust population extends from the disk's eastern side.
While HD 36546 intrinsic properties are consistent with a wide age range ($t$
$\sim$ 1--250 $Myr$), its kinematics and analysis of coeval stars suggest a
young age (3--10 $Myr$) and a possible connection to Taurus-Auriga's star
formation history. SCExAO's planet-to-star contrast ratios are comparable to
the first-light Gemini Planet Imager contrasts; for an age of 10 $Myr$, we rule
out planets with masses comparable to HR 8799 b beyond a projected separation
of 23 au. A massive icy planetesimal disk or an unseen superjovian planet at
$r$ $>$ 20 au may explain the disk's visibility. The HD 36546 debris disk may
be the youngest debris disk yet imaged, is the first newly-identified object
from the now-operational SCExAO extreme AO system, is ideally suited for
spectroscopic follow up with SCExAO/CHARIS in 2017, and may be a key probe of
icy planet formation and planet-disk interactions.
