[3] Lattimer has made several fundamental contributions to the field of nuclear astrophysics, with a particular focus on neutron stars.
One of his biggest impacts was modeling the birth of neutron stars from supernovae in 1986 with then-research assistant professor Adam Burrows.
In work that led to his PhD thesis, Lattimer and his advisor David N. Schramm first argued that the mergers of neutron stars and black holes would result in the ejection of neutron-rich matter in sufficient quantities to explain the origin of r-process elements such as gold and platinum.
[10] Mass ejection and r-process nucleosynthesis from decompression has been apparently observed[11] in the aftermath of GW170817, the first merger of two neutron stars detected by LIGO/VIRGO.
In 2015, Lattimer was awarded the Hans Bethe Prize for "outstanding theoretical work connecting observations of supernovae and neutron stars with neutrino emission and the equation of state of matter beyond nuclear density.