Dissertation defence (Astrophysics): MSc Shane Moran
Time
24.2.2025 at 12.00 - 16.00
MSc Shane Moran defends the dissertation in Astrophysics titled “Where Are the Stars of Yesteryear?: A Reflection on Astrophysical Transience” at the University of Turku on 24 February 2025 at 12.00 (University of Turku, Natura, X, Turku).
Opponent: Dr. Jonathan Mackey (Dublin Institute for Advanced Studies, Ireland)
Custos: Professor Seppo Mattila (University of Turku)
Doctoral Dissertation at UTUPub: https://www.utupub.fi/handle/10024/179982
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Summary of the Doctoral Dissertation:
Transients are objects that appear in the sky and then disappear or fade away, lasting between milliseconds and years. They include asteroids and comets, as well as supernovae, the high-energy explosions of stars. Many transients are a key source of chemical enrichment in the universe and transients can also be used to help gauge distances to far away objects and to provide indirect evidence about the nature of extremely distant stars.
In my thesis I explore various kinds of transients, including stars exploding into material that they have shed at an earlier time, stars whose outer layers have been stripped away by a companion star and stars venturing too close to black holes and being shredded by their gravity, resulting in great flashes of light.
The data collection and analysis that I have performed probes the observational features of these events, such as the presence of “dust echoes”, light from the explosion is scattered by dust before making its way to us, as well as providing insight into their physical origins and explosion mechanisms. This has a considerable bearing on stellar evolution as a whole and our understanding of the workings of the universe. I hope that my work will spur further investigation in the area, particularly given that there is a vast array of new telescopes and instruments on the horizon.
Opponent: Dr. Jonathan Mackey (Dublin Institute for Advanced Studies, Ireland)
Custos: Professor Seppo Mattila (University of Turku)
Doctoral Dissertation at UTUPub: https://www.utupub.fi/handle/10024/179982
***
Summary of the Doctoral Dissertation:
Transients are objects that appear in the sky and then disappear or fade away, lasting between milliseconds and years. They include asteroids and comets, as well as supernovae, the high-energy explosions of stars. Many transients are a key source of chemical enrichment in the universe and transients can also be used to help gauge distances to far away objects and to provide indirect evidence about the nature of extremely distant stars.
In my thesis I explore various kinds of transients, including stars exploding into material that they have shed at an earlier time, stars whose outer layers have been stripped away by a companion star and stars venturing too close to black holes and being shredded by their gravity, resulting in great flashes of light.
The data collection and analysis that I have performed probes the observational features of these events, such as the presence of “dust echoes”, light from the explosion is scattered by dust before making its way to us, as well as providing insight into their physical origins and explosion mechanisms. This has a considerable bearing on stellar evolution as a whole and our understanding of the workings of the universe. I hope that my work will spur further investigation in the area, particularly given that there is a vast array of new telescopes and instruments on the horizon.
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