"The main objective of our site is to provide a useful reference guide to the origins of the elements for researchers, educators and students. In this single site, we present both data and recent research results in a concise and attractive structure. Using tables and charts, the material is presented in a multi-level style.
Crab Nebula - "This image combines 24 individual exposures obtained with the Hubble Space Telescopes's Wide Field Planetary Camera 2 in 1999 and 2000. Images were taken through different color filters, each revealing different elements. Blue indicates neutral oxygen, green shows singly ionized sulfur, and red comes from doubly ionized oxygen."
Credit: NASA, ESA and Allison Loll / Jeff Hester (Arizona State University)