Star formation in globules in IC 1396^*

¹ Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2, Ireland e-mail: df@cp.dias.ie
² Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany

Received: 4 August 2004
Accepted: 8 November 2004

Abstract

We present a large-scale study of the IC 1396 region using new deep NIR and optical images, complemented by 2MASS data. For ten globules in IC 1396 we determine (, ) colour–colour diagrams and identify the young stellar population. Five of these globules contain a rich population of reddened objects, most of them probably young stellar objects. Two new HH objects (HH 865 and HH 864) could be identified by means of [SII] emission, one of them a parsec-scale flow. Using star counts based on 2MASS data we create an extinction map of the whole region. This map is used to identify 25 globules and to estimate their mass. The globule masses show a significant increase with the distance from the exciting O6.5V star HD 206267. We explain this correlation by the enhanced radiation pressure close to this star, leading to evaporation of the nearby clouds and hence smaller globule masses. We see evidence that the radiation from HD 206267 has a major impact on the star formation activity in these globules.