How much amount and what size of dust are formed in the ejecta of corecollapse supernovae (CCSNe) and are injected into the interstellar medium (ISM) depend on the type of CCSNe through the thickness of outer envelope. Recently Cas A was identified as a Type IIb SN (SN IIb) that is characterized by the thin hydrogen envelope. In order to clarify how the amount of dust formed in the ejecta and s...

background: fire and explosion hazards are extremely important in processing units. this study was performed to identify the risk centers, the potential damage caused by fire and explosion, and the days of production cessation in the processing company. materials and methods: the present qualitative case study was conducted using dow’s index in 2015. the fire and explosion hazard index and leve...

Two images of Cassiopeia A obtained at 24 micrometers with the Spitzer Space Telescope over a 1-year time interval show moving structures outside the shell of the supernova remnant to a distance of more than 20 arc minutes. Individual features exhibit apparent motions of 10 to 20 arc seconds per year, independently confirmed by near-infrared observations. The observed tangential velocities are ...

The progenitor of SN 2005cs, in the galaxy M51, is identified in pre-explosion HST ACS WFC imaging. Differential astrometry, with post-explosion ACS HRC F555W images, permitted the identification of the progenitor with an accuracy of 0.006. The progenitor was detected in the F814W pre-explosion image with I = 23.3± 0.2, but was below the detection thresholds of the F435W and F555W images, with ...

We describe multiwavelength observations of the evolving spectra and images of Supernova (SN) 1987A, and we review the principles used to infer the physical conditions in the explosion debris. We interpret the early optical and gammaray light curves with a simple diffusion model. We review the evidence for dust formation in the debris. We show X-ray and optical observations that enable us to ch...