Ultracool dwarf binary (IMAGE) Northwestern University Caption An illustration shows how close the ultracool dwarf binary stars currently are and how that closeness has changed over time. Credit Adam Burgasser/University of California San Diego Usage Restrictions Add credit License Original 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.