# Astrophysics News & Events

Gr@v member Tjarda Boekholt recently travelled to the University of Concepcion in Chile. He was invited by the Theory and Starformation Group (TSG), which is led by a team of professors including Mike Fellhauer, Dominik Schleicher, Amelia Stutz and Stefano Bovino. In the first week Tjarda lectured students on the Astrophysical Multi-purpose Software Environment (AMUSE). In particular, they discussed the coupling between N-body and hydrodynamics.

The CIDMA Young Doctor Award is a prize for a researcher within 5 years after the PhD, who has made important contributions to his or her research field. The 2018 award is granted to Gr@v member Tjarda Boekholt for his recent achievements in the field of dynamical chaos in astronomical systems. During the annual meeting of CIDMA 2018, Tjarda presented his new numerical N-body code and the ability to obtain reversible solutions to highly chaotic systems.

In a recent paper "Head on collisions of Proca Stars", [arXiv:1806.07779], by N. Sanchis-Gual *et al.*, head-on collisions of exotic compact objects known as "Proca stars" were studied via fully non linear numerical simulations, with the goal of extracting the gravitational wave templates that such exotic objects could produce.

Black hole (BH) shadows in dynamical binary BHs have been produced via ray-tracing techniques on top of computationally expensive fully non-linear numerical relativity simulations.

On arXiv:1805.03798 [gr-qc], it is illustrated (as a proof of concept) that the main features of these shadows can be captured by a simple quasi-static evolution of the photon orbits on top of a static double-Schwarzschild family of solutions, which is exact.

A team of Gr@v members (P. Cunha, J. Delgado, C. Herdeiro and J. Oliveira) is visiting the *Universidad Nacional Autónoma de México*, at its Cuernava Campus, in April-May 2018 hosted by Professor Juan Carlos Degollado. The visit occurs within a Marie Curie RISE action, of which both UNAM and Aveiro Universities are partners.

On May 29th, 1919 a joint Royal Astronomical Society and Royal Society expedition led by Arthur Eddington to Principe observed a total solar eclipse, confirming the deflexion of light predicted by the General Theory of Relativity. Eddington at Sundy: 100 years later (E@S) results from a joint initiative of several institutions, including our group, to celebrate the centenary of these observations.