CLEA researcher Clément Vidal will be giving an online seminar for the European Astrobiology Institute on Tuesday, February 18, 2025 at 16:00 CET, 7am PT, 10am ET.
Zoom link for the seminar here.
Abstract
Astrobiology is mostly guided by life as we know it on Earth. However, one can instead be guided by the fundamental constraints and functions of living systems to cast a broader net, and also search for life as we don’t know it. In this seminar, we propose to examine an example of an exotic lifeform at a stellar scale: organisms feeding on stars, or stellivores (Vidal 2016). The stellivore hypothesis suggests that some known accreting binary star systems (cataclysmic variables, X-ray binaries) might be living systems. The key question is: are these systems simply dissipative structures, or living systems? What predictions can we make to settle this issue?vIn order to probe the stellivore hypothesis we review three axes of research. First, we examine power density data in accreting binaries, and the plausibility of interpreting the dynamic phenomenology of these binaries as a controlled metabolism (Vidal 2019b).Second, we introduce the reliability and stability of millisecond pulsars signals, as these can be used as a kind of galactic GPS, or pulsar positioning system (Vidal 2019a) remarkably accurate down to 100 meters. Third we argue that a subset of millisecond pulsars - spider pulsars - can be interpreted as stellar engines in operation (Vidal 2024). Although the stellivore hypothesis is certainly an exotic and speculative lifeform proposal, it has the advantage of being testable with existing astrophysical data.
Trailer: https://youtu.be/RQbBz9bu64M
Video of the seminar: https://www.youtube.com/watch?v=U0peV5j2L2c