  We present the results of the first broadband 10.8 um survey of the NGC 2024
cluster. The mid-infrared data were combined with our previously published JHKL
photometry in order to construct spectral energy distributions for all detected
sources. The main scientific goals were to investigate the nature of the young
stellar objects (YSOs) in the cluster, and to examine the efficiency of
detecting circumstellar disk sources from near-infrared JHKL color-color
diagrams. Out of 59 sources surveyed having K-band magnitudes K < 10.5, we
detected 35 (~59%) at 10 um. Combining these detections, and upper limits for
the non-detections, with existing JHKL data, we identify 1 Class I, 6 flat
spectrum, 28 Class II and 5 Class III sources. We find a circumstellar disk
fraction for NGC 2024 of ~85% +/- 15%, which confirms earlier published
suggestions that the majority, if not all, of the stars in NGC 2024 formed with
disks, and these disks still exist at the present time. In addition, all but
one of the disk sources identified in our survey lie in the infrared excess
region of the JHKL color-color diagram for the cluster. This demonstrates that
JHKL color-color diagrams are extremely efficient in identifying YSOs with
disks. Of the 14 sources with K - L colors suggestive of protostellar objects,
\~29% are protostellar in nature, while ~7% are true Class I YSOs. This may be
due to extinction producing very red K - L colors in Class II YSOs, thus making
them appear similar in color to protostars. This suggests caution must be
applied when estimating the sizes and lifetimes of protostellar populations
within star forming regions based on K - L colors alone. Finally, we calculate
the luminosities of the Class II YSOs in NGC 2024, rho Oph and Taurus and
discuss the results.
