Complex Structure in β Leo's disk

The Structure of the β Leonis Debris Disk
http://arxiv.org/abs/1010.0003

Quote :

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.

Modelling the Beta Leonis debris system seems to have various possibilities:

Multi-Wavelength Modelling of the Beta Leo Debris Disc: 1, 2 or 3 planetesimal populations?

Seems to recall the ambiguity about what the planetesimal populations are like at Epsilon Eridani.