Star forming regions

For the largest telescopes being developed (w 30m) the diffraction limit at a wavelength of l/ttm is about 50 parsecs at z = 2 — 8, or about lAU at 150pc (the nearest star forming regions). 

Abstract. We use intermediate resolution (II, 19 300) spectroscopic observations in the spectral region including the Li 6708 A line to study 341 stars in the star forming region (SFR) NGC 6530. Based on the optical color-magnitude diagrams (CMD), they are G, K and early M type pre-main sequence (PMS) cluster candidates. 72% of them are probable cluster members since are X-ray sources detected in a Chandra-ACIS observation ([2]). We use our spectroscopic measurements to confirm cluster membership by means of radial velocities and to investigate the Li abundance of cluster members. 

Dopita, M.A., 1986IAU Symposium 115 "Star-Forming Regions", ed M.Peimbert and J. Jugaku, Dondrecht Reidel, p501. 

IC 348 and Chamaeleon I star-forming regions 2 Myr, warm dust disks around -50-65% of stars (Luhman 2008)... 

Multiple lines of evidence exist for a population of live radionuclides, such as 26Al or 60Fe, which were injected into the proto-solar cloud or disk prior to the formation of CAIs (e.g. Tachibana et al. 2006). Isotopic abundances suggest that the isotopes have originated in a supernova, possibly with a very massive star progenitor that also underwent a Wolf-Rayet phase (Bizzarro et al. 2007). If this interpretation is correct, the Sun must have formed in a very rich and dense stellar cluster, such as the Carina Nebula, very much unlike the Taurus or other low-mass star-forming regions. Luminous massive stars in such clusters may truncate or fully evaporate protoplanetary disks around other cluster members. Two key questions remain open. How close in time and space did the supernova explode... 

Herschel Open Time Key Program Gas in Protoplanetary Systems 1 will obtain spectra of far-infrared atomic and molecular lines from over 240 disks in nearby star-forming regions with ages in the critical 1-30 Myr range over which gas clears out and planets form. 

Finally, it is important to remember that the Solar System probably formed in a cluster, near to massive stars, while most studies so far have focused on the evolution of disks in nearby low-mass star-forming regions. We feel that future observations should aim at a better characterization of the evolution of the inner disks in clusters for comparison with the evolution of the proto-solar nebula. 

Classification Cold dense cloud Outflowing C-rich circum-stellar envelope Warm molecular cloud/star-forming region Giant molecular cloud... 

Observations of star-forming regions have advanced our understanding of the star-formation process considerably in the last few decades. We now can study examples of nearly aU phases of the evolution of a dense molecular cloud core into a nearly fully formed star (i.e., the roughly solar-mass T Tauri stars). As a result, the theory of star formation is relatively mature, with fumre progress expected to center on defining the role played by binary and multiple stars and on refining observations of known phases of evolution. 

---