The field of IC 2602: Strömgren-Hβ photometry approach

Abstract

A homogeneous data-base collating all uvbyβ photometry available at present for O-B9 stars in the field of IC 2602 is presented. The characteristics of the field are studied. Four spatially coherent groups can be distinguished. A low reddened compact group located at 156±6 pc is identified with IC 2602, followed by background layers at 546±33 pc, 1117±61 pc, and possibly at 2626±163 pc. The apparent depth of the first three layers is about 1 kpc, which is consistent with the thickness of a spiral arm. There is an indication for the existence of a region free of massive luminous stars between 1.2 and 2.6 kpc, which could be associated with interarm space between the Local Association and the distant spiral structures toward Carina. A comparison between the photometric and Hipparcos parallaxes is presented.