A team of astronomers has discovered a faint blue dwarf galaxy nicknamed Leoncino or the "little lion," thatcould be used as a tool to test the Big Bang Theory. The little lion is the mostmetal-poor galaxy ever discovered, meaning that it could act as atime capsule, allowing scientists to glimpse the conditionsprevailing soon after the creation of our universe.
Shining blue in thelight of a new generation of stars, Leoncino (or AGC 198691) sitsroughly 30 million light-years distant from Earth in theconstellation Leo Minor. Astronomers were able to determine thegalaxy's low metal content by bringing to bear a pair ofspectrographs mounted on two Arizona based instruments – the Mayall4-meter telescope at the Kitt Peak National Observatory, and theMultiple Mirror Telescope, located at the Mount Hopkins summit.
Any element heavierthan helium and hydrogen is known as a metal. In metal-rich galaxiesheavier elements are created through the lifecycles of generations ofstars via a technique known as "stellar processing." Astar creates metals through nucleosynthesis, and distributes theseelements throughout the galaxy upon going supernova, seeding the nextgeneration of stars in the process.
A metal-poor galaxy isan environment wherein this process has been somehow stunted, leaving it witha chemical make-up similar to that of the early universe. Since ourcurrent model of the Big Bang makes fairly detailed predictionsregarding the ratio of hydrogen and helium atoms following thecreation of the universe, we can use these metal-poor time capsulesto test one of mankind's most venerated scientific theories.
"Finding the mostmetal-poor galaxy ever is exciting since it could help contribute toa quantitative test of the Big Bang," states John J. Salzer,associate professor of astronomy at Indiana University Bloomington,and co-author of a paper on the study. "There are relatively fewways to explore conditions at the birth of the universe, butlow-metal galaxies are among the most promising."
Moving forward, the teamhopes to undertake further observations of Leoncino in order tosqueeze as much information as possible out of the rare galactictreasure.
Source: Indiana University Bloomington