Investigating star formation in the young open cluster NGC 6383

Institut fu¨r Astronomie der Universit¨at Wien, Tu¨rkenschanzstr. 17, A-1180 Wien, AustriaReceived 2006; accepted 2006ABSTRACTContext. By studying young open clusters, the mechanisms important for star formation over several Myr can beexamined. For example, accretion rate as a function of rotational velocity can be investigated. Similarly, sequential starformation triggered by massive stars with high mass-loss rates can be studied in detail.Aims. We identified and characterized probable members of NGC 6383, as well as determined cluster parameters.Methods. New Str¨omgren uvby CCD photometry, obtained by us, is presented. This new data, together with JohnsonUBV and 2MASS data in the NIR, was used to investigate characteristics of pre- as well as zero age main sequencecluster members.Results. We present Str¨omgren uvby CCD photometry for 272 stars in the field of NGC 6383 and derive its reddening,E(b − y) = 0.21(4)mag, as well as distance, d=1.7(3)kpc from the Sun. Several stars with NIR excess and objectsin the domain of the classical Herbig Ae/Be and T Tauri stars were detected. Two previously known variables wereidentified as rapidly-rotating PMS stars. The field population is clearly separated from the probable members in thecolor-magnitude diagram.Conclusions. NGC 6383 is a young open cluster, with an age of less than 4 Myr, undergoing continuous star formation.True pre-main sequence members might be found down to absolute magnitudes of +6mag, with a variety of rotationalvelocities and stellar activities.Key words. Stars: pre-main sequence – stars: early-type – stars: formation – open clusters and associations: individual:NGC 6383