Using Hubble to reveal the impostor

Massive stars play a critical role in the evolution of the Universe; from the formation of the first heavy metals in the early Universe, to their dominating role in the evolution of their host galaxies and future generations of star formation. Although we can observe massive stars across the Universe, our understanding of the life and death of massive stars remains fragmented. A major gap in the stellar evolutionary theory involves in final moments of a massive stars life. With modern observing facilities, we have been able to capture peculiar observables in the years before a group of massive stars goes supernova.

In this talk, Seán  will present recent observations of a group of bright explosions where, until recently, we were unsure whether we were observing the death of a massive star or something else. Using the Hubble Space Telescope, we re-observed the site of these explosions almost 5 years after the star erupted. By modelling these remnant, Seán will discuss the possibility that the progenitors have survived these energetic explosions, making these apparent supernova impostors.

Seán Brennan is final year PhD student in the Supernova and Interacting Transient group at University College Dublin, Ireland, working with Dr. Morgan Fraser. His research interests include understanding the nature of interacting transients, and developing the new era of reduction pipelines for the modern astronomer’s toolbox.  His recent work relates to understanding the final moments of a massive stars’ life, and how, why, and when a progenitor star with undergo massive eruptions shortly before core-collapse, producing an interacting supernova. Seán will complete his PhD in late-August 2022, and will begin his Post Doc at the transient group at Stockholm University / Alba Nova Centre, working with Ragnhild Lunnan and the ZTF collaboration.