A Deep Look at Whirlpool Galaxy M51a (IMAGE) Case Western Reserve University Caption Case Western Reserve University astronomers found new features on the first-known spiral galaxy, M51a, which has been sketched and photographed for 170 years. Credit Aaron Watkins Usage Restrictions Please give proper credit. 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.