... Diffuse X-ray Emission from the Hydrogen-Deficient Planetary Nebula Abell 30 . ... diffuse X-ray emission within the planetary nebula shell of Abell30, using a 21.8-ks ... stellar wind or the central H-poor nebula shocking the ambient H-rich material ...
... Lawrence H. Aller and Siek Hyung . Astronomy Department, University of California, Los Angeles, California 90024, USA . ... The dusty young, low excitation, planetary nebula, BD +30 3639, denoted as ``Campbell's hydrogen envelope star'' has been the ...
... Space Sciences Laboratory, University of California, Berkeley, CA94720, U.S.A. We present three new images of the young, carbon rich planetary nebula, IC 418: 11.3 m dust emission, a [NeII] 12.8 m line emission and 6 cm free-free continuum. ...
... Examples include the Coalsack Nebula in Crux and the famous Horsehead Nebula in Orion. ... The Horsehead Nebula, a dense molecular cloud (dark nebula) in the Orion region. ...
... Astronomy Department, Campbell Hall, University of California, Berkeley, CA94720, U.S.A. Space Sciences Laboratory, University of California, Berkeley, CA94720, U.S.A. We present ground based images in the 10 m window of the post-AGB star HD161796. ...
... UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 USA . ... stars, objects that are believed to represent the first phases of the transition from the AGB to the planetary nebula stage ...