We report the results of the first sensitive L -band ( 3.4 \mu m ) imaging survey of the young IC 348 cluster in Perseus .
In conjunction with previously acquired JHK ( 1.25 , 1.65 , 2.2 \mu m ) observations , we use L -band data to obtain a census of the circumstellar disk population to m _ { K } = m _ { L } \leq 12.0 in the central \sim 110 arcmin ^ { 2 } region of the cluster .
An analysis of the JHKL colors of 107 sources indicates that 65 % \pm 8 % of the cluster membership possesses ( inner ) circumstellar disks .
This fraction is lower than those ( 86 % \pm 8 % and 80 % \pm 7 % ) obtained from similar JHKL surveys of the younger NGC 2024 and Trapezium clusters , suggesting that the disk fraction in clusters decreases with cluster age .
Sources with circumstellar disks in IC 348 have a median age of 0.9 Myr , while the diskless sources have a median age of 1.4 Myr , for a cluster distance of 320 pc .
Although the difference in the median ages between the two populations is only marginally significant , our results suggest that over a timescale of \sim 2 – 3 Myr , more than a third of the disks in the IC 348 cluster disappear .
Moreover , we find that at a very high confidence level , the disk fraction is a function of spectral type .
All stars earlier than G appear diskless , while stars with spectral types G and later have a disk fraction ranging between 50 % – 67 % , with the latest type stars having the higher disk fraction .
This suggests that the disks around stars with spectral types G and earlier have evolved more rapidly than those with later spectral types .
The L -band disk fraction for sources with similar ages in both IC 348 and Taurus is the same , within the errors , suggesting that , at least in clusters with no O stars , the disk lifetime is independent of environment .