年轻恒星
1.Disks have also been observed around many young stars; astronomers often call them protoplanetary disks because they appear to be similar to the one that must have formed our own solar system.
3.Previously, some astronomers had suggested that the anomalous arms are jets of particles being ejected by a supermassive black hole in nucleus of NGC 4258.
4.In. contrast with Pup I stars the Li abundances of Pup Ⅱ F- and early G-type dwarfs show a very small dispersion and they are about an order of magnitude smaller than the value of the young Pup I stars.
5.We present H and K s polarimetric images in a ～5′ field of star forming region NGC7538. The polarimetric images reveal the complex structure of infrared nebulosities and clusters of young stars, associated with the bright infrared sources IRS 1 11. The polarization pattern in the IRS 1 3 nebula shows a dominant illumination from deeply embedded source IRS 1. The morphology of the nebula can be modeled by a low extincted bubble enclosed by redder and highly polarized shell.
