Pasadena, CA— Carnegie’s Allan Sandage, who died in 2012, was a tremendously influential figure in the field of astronomy. His final paper, published posthumously, focuses on unraveling a surprising historical mystery related to one of his own seminal discoveries.

While preparing a centennial history of the Carnegie Observatories in the early 2000s, Sandage came across an unpublished 1944 exchange between two prominent astronomers that piqued his interest. The conversation seemed to predate by a decade Sandage’s own work on stellar evolution in the mid-1950s.

Naturally, he wanted to investigate further.

Pasadena, CA—The lightest few elements in the periodic table formed minutes after the Big Bang.  Heavier chemical elements are created by stars, either from nuclear fusion in their interiors or in catastrophic explosions.  However, scientists have disagreed for nearly 60 years about how the heaviest elements, such as gold and lead, are manufactured.  New observations of a tiny galaxy discovered last year show that these heavy elements are likely left over from rare collisions between two neutron stars. The work is published by Nature.

The new galaxy, called Reticulum II because of its location in the southern constellation Reticulum, commonly known as The Net, is one of the smallest and closest to us known.  Its proximity made it a tempting target for a team of astronomers including Carnegie’s Josh Simon, who have been studying the chemical content of nearby galaxies.