The document summarizes research on the first luminous objects in the early universe, including the first stars and their deaths in supernovae. Massive first stars between 80-250 solar masses died in pair-instability supernovae or pulsational pair-instability supernovae, enriching the interstellar medium with metals. Later population II and III stars formed in the first galaxies around redshift 10-20, which were influenced by feedback from earlier stellar populations. Observations of supernovae, gamma rays, and gravitational waves may reveal more about the first stars and galaxies.