Near-infrared and optical observations of IRAS sources in and near dense cores

Abstract

The authors report photometry from 0.4 to 20 μm of 34 IRAS point sources associated with dense cores in dark clouds. The main results of this study are: (1) Stars near cores tend to be visible T Tauri stars, while stars in cores tend to have circumstellar extinction A<SUB>V</SUB> ≡ 30 - 90 mag and luminosity ≡1 L_sun;, similar to that of T Tauri stars. (2) The typical highly obscured star is probably accompanied by a luminous structure of substellar temperature, such as a circumstellar disk. (3) In Taurus-Aurigae, stars in cores probably become visible T Tauri stars less than 1×10<SUP>5</SUP>yr after they attain luminosity greater than ≡0.1 L_sun;. This implies that they are extremely young and may still be accreting.