18–23 Jun 2017
Laboratori Nazionali del Sud
Europe/Rome timezone

When Stars Attack! Live Radioisotopes Reveal Near-Earth Supernovae

19 Jun 2017, 09:10
30m
Sala conferenze (Laboratori Nazionali del Sud)

Sala conferenze

Laboratori Nazionali del Sud

Via S. Sofia 62 I-95123 Catania Italy
Invited talk Explosive scenarios in astrophysics: observations, theory, and experiments Explosive nucleosynthesis observations

Speaker

Prof. Brian Fields (Departments of Astronomy and of Physics, University of Illinois)

Description

% % Nuclear Physics in Astrophysics 8 template for abstract % % Format: LaTeX2e. % % Rename this file to name.tex, where `name' is the family name % of the first author, and edit it to produce your abstract. % \documentstyle[11pt]{article} % % PAGE LAYOUT: % \textheight=9.9in \textwidth=6.3in \voffset -0.85in \hoffset -0.35in \topmargin 0.305in \oddsidemargin +0.35in \evensidemargin -0.35in \def\iso#1#2{\mbox{${}^{#2}{\rm #1}$}} \def\fe6#1{\iso{Fe}{6#1}} %\renewcommand{\rmdefault}{ptm} % to use Times font \long\def\TITLE#1{{\Large{\bf#1}}}\long\def\AUTHORS#1{ #1\\[3mm]} \long\def\AFFILIATION#1#2{$^{#1}\,$ #2\\} \begin{document} {\small \it Nuclear Physics in Astrophysics 8, NPA8: 18-23 June 2017, Catania, Italy} \vspace{12pt} \thispagestyle{empty} \begin{center} %%% %%% Title goes here. %%% \TITLE{When Stars Attack! \\ Live Radioisotopes Reveal Near-Earth Supernovae }\\[3mm] %%% %%% Authors and affiliations are next. The presenter should be %%% underlined as shown below. %%% \AUTHORS{Brian D. Fields$^{1,2}$} %%% {\small \it \AFFILIATION{1}{Department of Astronomy, University of Illinois} \AFFILIATION{2}{Department of Physics, University of Illinois} } %%% \vspace{12pt} % Do not modify % Enter contact e-mail address here. \centerline{Contact email: {\it bdfields@illinois.edu}} \vspace{18pt} % Do not modify \end{center} %%% %%% Abstract proper starts here. %%% Supernovae are major engines of nucleosynthesis, and create many of the elements essential for life. Yet these awesome events take a sinister shade when they occur close to home, because an explosion very nearby would pose a grave threat to Earthlings. We will show how radionuclides produced by supernovae can reveal nearby events in the geologic past, and we will highlight isotopes of interest. In particular, accelerator mass spectrometry has detected live \fe60 globally in deep-ocean material, and in lunar samples. We will review astrophysical \fe60 production sites and show that the data demand that one or more core-collapse supernovae exploded near the Earth $\sim ~3$ Myr ago, and explain how debris from the explosion was transported to the Earth as a ``radioactive rain.'' The \fe60 measurements represent a new tool for nuclear astrophysics: we can now use sea sediments and lunar cores as telescopes, probing supernova nucleosynthesis and possibly even indicating the direction towards the event(s). We will close by reviewing recent work showing that an explosion so close was probably a ``near-miss'' that exposed the biosphere to intense and possibly harmful ionizing radiation. %%[1,2]. \bigskip {\small %%\noindent [1] E. Stark, Phys. Journal of the North 83 045801 (2011); \noindent %%[2] O. Martell et al. submitted to Solar Physics Letters (2013).} %%% %%% End of abstract. %%% \end{document}

Primary author

Prof. Brian Fields (Departments of Astronomy and of Physics, University of Illinois)

Presentation materials