Janus, the two-faced white dwarf (IMAGE) Institute of Science and Technology Austria Caption The two-faced white dwarf, nicknamed Janus. This star remnant is composed primarily of hydrogen on one side (brighter blue) and helium on the other. Artist’s representation. Video: Ilaria Caiazzo talks about the two-faced white dwarf Janus (Caltech) Credit © K. Miller, Caltech/IPAC Usage Restrictions Free to use when reporting about topic. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.