  We combine nulling interferometry at 10 {\mu}m using the MMT and Keck
Telescopes with spectroscopy, imaging, and photometry from 3 to 100 {\mu}m
using Spitzer to study the debris disk around {\beta} Leo over a broad range of
spatial scales, corresponding to radii of 0.1 to ~100 AU. We have also measured
the close binary star o Leo with both Keck and MMT interferometers to verify
our procedures with these instruments. The {\beta} Leo debris system has a
complex structure: 1.) relatively little material within 1 AU; 2.) an inner
component with a color temperature of ~600 K, fitted by a dusty ring from about
2 to 3 AU; and 3.) a second component with a color temperature of ~120 K fitted
by a broad dusty emission zone extending from about ~5 AU to ~55 AU. Unlike
many other A-type stars with debris disks, {\beta} Leo lacks a dominant outer
belt near 100 AU.

Earth and Planetary Astrophysics;Solar and Stellar Astrophysics