Periodic Reporting for period 4 - Fireworks (Celestial fireworks: revealing the physics of the time-variable sky)
Reporting period: 2022-03-01 to 2023-07-31
This project is aimed at studying transient astrophysical phenomena on timescales shorter than previously possible - nightly (subproject 1), hourly (subproject 2) and down to minure/second timescale (subproject 5), as well as to collect and analyse large samples of such events (subproject 3) and to develop new tools and methods that will help to find unusual objects (subproject 4).
Understanding transient astrophysical phenomena is a key to understanding fundamental problems in astrophysics and physics in general, and move our understanding of the physical universe surrounding us forward.
Understanding transient astrophysical phenomena is a key to understanding fundamental problems in astrophysics and physics in general, and move our understanding of the physical universe surrounding us forward.
All subprojects were concluded successfully. The project contributed significantly to the study of transients of all types on timescales of days (especially young, 1-2 days old supernova explosions) and pioneered studies of the transient sky down to timescales of minutes with the W-FAST facility. It led to numerous high-impact and highly visible publications. It provided valuable training to young scientists, including thesis projects for students as well as training to postdoctoral students, some of whom now hold tenure-track positions.
We have:
* measured for the first time the fraction of all massive stars that explode within clouds of surrounding matter, and showed this is ubiquitous (60% of cases), indicating that massive stars undergo a period of rapid
mass loss prior to their terminal explosion; this is unexplained by standard models of stellar evolution, and require a new thinking about massive star evolution, structure, and explosion as supernovae.
* We have found the first example of an exploding star within a Wolf-Rayet wind nebula.
* We have contributed to the discovery of the first gravitational-wave counterpart, GW170817.
* measured for the first time the fraction of all massive stars that explode within clouds of surrounding matter, and showed this is ubiquitous (60% of cases), indicating that massive stars undergo a period of rapid
mass loss prior to their terminal explosion; this is unexplained by standard models of stellar evolution, and require a new thinking about massive star evolution, structure, and explosion as supernovae.
* We have found the first example of an exploding star within a Wolf-Rayet wind nebula.
* We have contributed to the discovery of the first gravitational-wave counterpart, GW170817.