DISTRIBUTION OF HOT STARS AND INTERSTELLAR DUST IN CARINA

From the results of observations with the "Glazar" astronomical telescope of a region of Carina containing the Carina nebula we have studied the spatial distribution of 150 stars of early spectral classes. It is shown that in the direction of observation the law of interstellar absorption is normal. In the region under study five stellar associations of 0 type at distances about 1100, 2000, 3000, 4000, and 5000 pc were observed. At a near distance of 560 pc a group of stars of relatively late spectral classes (B3-B9) was observed. In this group a close system of stars consisting of five members was discovered. It is shown that three of the clusters located in this direction, NGC 3293, Bo 10, and IC 2581 (Cr 222) belong to the association Car OB 2.0 at a distance of about 2200 pc. Another cluster observed here, NGC 3324, seems to belong to the association Car OB 3.0 at a distance of about 2900 pc. It is shown that up to distances of about 1000 pc there is a layer of dust causing minimal absorption of radiation 1'?.5 at )~ 1640 A of the stars located beyond this layer. In the volume of observed stellar associations the dust is distributed very unevenly. In the space between the associations there is no dust. 1. Introduction. The authors [1] have presented the results of observations in the direction of the stellar association Car OB1 carried out using the "Glazar" astronomical telescope. On an area of the sky of approximately 13 square degrees 233 stars brighter than 8~.5 at )~ 1640 A were detected. All these stars are stars of earlier spectral classes. In the direction of the region being observed the visual ray passes along the arm of Carina to a depth of up to 5-6 kpc. This region contains the noteworthy Carina nebula (NGC 3372) together with the multiple star ~ Car and several stellar clusters--Tr 14, Tr 15, Tr 16, IC 2581 (Cr 222), NCG 3324 (Cr 225), Cr 228, Cr 232, Bo 10, Bo 11, and NGC 3293. The stellar association Car OB1 and part of the stellar association Car OB2 are also located here. This region has been intensively studied by many investigators, and widely differing values have been given for the distances of the stellar clusters and associations, from 2.0 kpc to 3.7 kpc [2-22]. The results of a study of the distribution of the OB-stars observed in the region of the Carina nebula are given in [23], where it is shown that four of the six stellar clusters that project onto the nebula are actually located inside the nebula and constitute a single complex. It was also shown that the law of interstellar absorption in the Carina nebula is anomalous.