Abstract
The first detection of a S-36-bearing molecule in interstellar space is reported. The J=2-1 and 3-2 transitions of (CS)-S-36 have been observed toward eight Galactic molecular hot cores. From a comparison with other optically thin isotopic species of CS, the abundance ratio of S-34/S-36 is 115(+/-17). This is smaller than the solar system ratio of 200 and supports the idea that S-36 is, unlike the other stable sulfur isotopes, a purely secondary nucleus that is produced by s-process nucleosynthesis in massive stars.