Circumstellar Disk Frequency in Young Clusters and the Timescale for Planet Formation
          José Carlos Correla, University of Lisbon, Portugal
          Paula Teixeira, CfA, USA
          Sofia Fernandes, University of Lisbon, Portugal
          João Alves, ESO, Germany
          Charles Lada, CfA, USA
          Elizabeth Lada, University of Florida, USA
          Filipe D. Santos, University of Lisbon, Portugal

          We present the results of a near-infrared study of the young stellar clusters NGC 2547 and NGC 2316. The aim of this study was to determine the frequency of circumstellar disks in these clusters by computing near-infrared excesses. JHK photometry was used to construct color-color diagrams and determine the fraction of young stellar objects with disks. The results are discussed and conclusions are taken regarding the constraints on the timescale for planet formation.