Anna Watts

NICER, the Neutron Star Interior Composition Explorer, is an X-ray telescope that installed on the International Space Station. Its mission is to study the nature of the densest matter in the Universe, found in the cores of neutron stars.  NICER uses Pulse Profile Modeling, where we use relativistic effects on X-rays emitted from the hot magnetic polar caps of millisecond pulsars to measure the mass and radius of the neutron star.  The technique also lets us create a map of the hot emitting regions on the  neutron star’s surface.   I will present NICER’s latest results – including a measurement of the size of the most massive neutron star – and discuss the implications for our understanding of ultradense matter, pulsar emission, and stellar magnetic fields.