11 papers
Deciphering the "Green Monster" in Cassiopeia A: Puncturing and sculpting a heterogeneous circumstellar shell
S. Orlando, H. -T. Janka, D. Milisavljevic +6
JWST observations of Cassiopeia A have revealed the "Green Monster" (GM), a pockmarked region of shocked circumstellar medium (CSM) characterized by circular holes surrounded by br…
Detection of High-Velocity NaI Absorption Toward the Stellar Remnant of SN 1181 AD
Peter Garnavich, Robert A. Fesen
We report the detection of weak high-velocity NaI absorption at V = km s in the spectrum of the stellar remnant at the center of the Galactic sup…
The Ejecta Nebula Around the Wolf-Rayet Star WR 71
Robert A. Fesen, Manuel C. Peitsch, Martin R. Pugh +2
We present deep H and [O III] images of the ejecta rich nebulosity associated with the suspected runaway and binary Wolf-Rayet star WR~71 (HD 143414). In H emission, the ne…
Deep Optical Images of the Ejecta Nebula Around the Wolf-Rayet Star WR 8 (HD 62910)
Robert A. Fesen, Daniel Patnaude, Wei-Hao Wang +7
We report the results of deep H and [O III] images of the bright WN6/WC4 Wolf-Rayet star WR~8 (HD~62910). These data show considerably more surrounding nebulosity than seen in…
Cassiopeia A's Reverse Shock and its Effects on the Expanding SN Ejecta
Robert A. Fesen, Dan Milisavljevic, Daniel Patnaude +4
Using optical and near-infrared images of the Cassiopeia A (Cas A) supernova remnant covering the time period 1951 to 2022, together with optical spectra of selected filaments, we…
Late-Time Optical and X-ray Emission Evolution of the Oxygen-Rich SN 1996cr
Daniel Patnaude, Kathryn Weil, Robert Fesen +2
When the ejecta of supernovae interact with the progenitor star's circumstellar environment, a strong shock is driven back into the ejecta, causing the material to become bright op…