Searching for axion stars with a global network of optical atomic magnetometers*

The GNOME collaboration (the Global Network of Optical Magnetometers to search for Exotic physics) is using a worldwide network of optical atomic magnetometers to search for correlated transient signals heralding new physics [Pospelov et al., Phys. Rev. Lett. {\textbf{110}}, 021803 (2013)]. Potential search targets for the GNOME include compact dark-matter objects such as axion stars [Jackson Kimball et al., arxiv:1710.04323]. We discuss the particular implementation and characteristics of the Hayward GNOME magnetometer and analyze prospects for detecting a terrestrial encounter with an axion star by the GNOME.