Two binary neutron star mergers have been detected from their gravitational wave signature. The first, in 2017 had an electromagnetic counterpart comprising a high energy and radio emission and a thermal component called a kilonova powered by radioactive heavy elements. The composition of the ejecta, mostly elements heavier than iron is still debated. Nucleosynthesis and atomic data arguments suggest a number of 1st and 2nd process elements have detected spectral signatures. The was no counterpart from the second binary neutron star merger in 2019 and no further merger has been detected by LIGO-Virgo-Kagra since. However, surprisingly two long gamma ray bursts have shown convincing signatures of an infra-red excess powered by heavy element decay, and the luminosity can be modelled with kilonova thermal emission. I will present the data, current debates on the chemical element signatures in the spectrum, discuss the relatively low rate of discovery and the put the two long GRB discoveries into context. To arrange a visit with the speaker during the visit, please contact their host: Fabian Schneider