Search for young stars among ROSAT All-Sky Survey X-ray sources in and around the R CrA dark cloud

We present the ROSAT All-Sky Survey data in a 126 deg(2) area in and around the CrA star forming region. With low-resolution spectroscopy of unidentif ied ROSAT sources we could find 19 new pre-main sequence stars, two of whic h are classical T Tauri stars, the others being weak-lined. The spectral ty pes of these new T Tauri stars range from F7 to RIG. The two new classical T Tauri stars are located towards two small cloud-lets outside of the main CrA cloud. They appear to be similar to 10 Myrs Old, by comparing their loc ation in the H-R diagram with isochrones for an assumed distance of 130 pc, the distance of the main CrA dark cloud. The new off-cloud weak-line T Tau ri stars may have formed in similar cloudlets, which have dispersed recentl y. High-resolution spectra of our new T Tauri stars show that they have sig nificantly more lithium absorption than zero-age main-sequence stars of the same spectral type, so that, they are indeed young. From those spectra we also obtained rotational and radial velocities. For some stars we found the proper motion in published catalogs. The direction and velocity of the 3D space motion - south relative to the galatic plane - of the CrA T Tauri sta rs is consistent with the dark cloud being formed originally by a high-velo city cloud impact onto the galactic plane, which triggered the star formati on in CrA. We also present VRIJHK photometry for most of the new T Tauri st ars to derive their luminosities, ages, and masses.