Cool Stars 14 - Submitted Abstract # 232 This version created on 05 October 2006 A Study of Angular Momentum of Pre-Main Sequence Stars in IC 348 Nairn Baliber, University of Texas at Austin Lucas Cieza, University of Texas at Austin We present results from an angular momentum study of the stars in the young cluster IC 348. We measured 105 stellar rotation periods, 75 of which are new detections, increasing the total number of known periods in this cluster to 143. Stars estimated to be less massive than 0.25 solar masses show a unimodal distribution of fast rotators, peaking at 1 - 2 days, with a tail of slower rotators, while stars estimated to be more massive than 0.25 solar masses show a bimodal distribution with peaks at ~2 and ~8 days, resembling the distribution seen in the heart of the Orion Nebula Cluster by Herbst and colleagues. We combine all published rotation periods in IC 348 with Spitzer IRAC mid-IR photometry, an unprecedentedly efficient and reliable disk indicator, in order to test the disk-braking paradigm. We find no evidence that the tail of slow rotators in low-mass stars or the long period peak in high-mass stars are preferentially populated by objects with disks as might be expected based on the current disk-braking model. We find some indication that the disk fraction decreases significantly for stars with very short periods (P < 1.5 days), which is the only feature of our sample that could potentially be interpreted as evidence for disk braking. We present preliminary results from Monte Carlo simulations we are running to perform a rigorous quantitative analysis of observational data from three young clusters in order to determine if the disk-braking model is inconsistent with these data. ----------------------------------