Latest Metallicity Stories

Every cook knows the ingredients for making bread: flour, water, yeast, and time. But what chemical elements are in the recipe of our universe?Most of the ingredients are hydrogen and helium. These cosmic lightweights fill the first two spots on the famous periodic table of the elements.Less abundant but more familiar to us are the heavier elements, meaning everything listed on the periodic table after hydrogen and helium. These building blocks, such as iron and other metals, can be found in...

BOSS, the Baryon Oscillation Spectroscopic Survey, is the most ambitious attempt yet to map the expansion history of the Universe using the technique known as baryon acoustic oscillation (BAO). A part of the Sloan Digital Sky Survey III (SDSS-III), BOSS achieved "first light" on the night of September 14-15, when it acquired data with an upgraded spectrographic system across the entire focal plane of the Sloan Foundation 2.5-meter telescope at Apache Point Observatory in New...

Data from NASA's Galaxy Evolution Explorer spacecraft may force astronomers to discard the assumption that stars of certain sizes form in certain quantities. For decades, astronomers have believed the proportion of small to big stars was fixed. For every star 20 or more times as massive as the sun, for example, there should be 500 stars with the sun's mass or less. But that belief, based on years of research, has been shattered with data from the spacecraft's ultraviolet telescope. That data...

Using ESO's Very Large Telescope, astronomers have succeeded in measuring the size of giant galaxy Messier 87 and were surprised to find that its outer parts have been stripped away by still unknown effects. The galaxy also appears to be on a collision course with another giant galaxy in this very dynamic cluster.The new observations reveal that Messier 87's halo of stars has been cut short, with a diameter of about a million light-years, significantly smaller than expected, despite being...

There is more than one way to make a dwarf galaxy, and NASA's Galaxy Evolution Explorer has found a new recipe. It has, for the first time, identified dwarf galaxies forming out of nothing more than pristine gas likely leftover from the early universe. Dwarf galaxies are relatively small collections of stars that often orbit around larger galaxies like our Milky Way.The findings surprised astronomers because most galaxies form in association with a mysterious substance called dark matter or...

There's a universal tendency to heed Dylan Thomas's exhortation and go out with a bang instead of a whimper. Nowhere is this more evident than deep in the cosmos. When their time is up, stars make their exits in a number of flamboyant ways. The most massive stars leave with the greatest fanfare of all "“ blasting out gamma-ray bursts (GRBs), tremendous explosions that rock the Universe like nothing else. These spectacular blasts, second in power only to the Big Bang, occur when stars 50 to...

Although the universe contains billions of galaxies, only a small amount of its matter is locked up in these behemoths. Most of the universe's matter that was created during and just after the Big Bang must be found elsewhere.Now, in an extensive search of the local universe, astronomers say they have definitively found about half of the missing normal matter, called baryons, in the spaces between the galaxies. This important component of the universe is known as the "intergalactic...

Millions of clustered stars glisten like an iridescent opal in a new image from NASA's Spitzer Space Telescope. Called Omega Centauri, this sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the more than 150 similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus. Spitzer's new infrared view, which has been...

Astronomers have at last found definitive evidence that the universe's first dust "“ the celestial stuff that seeded future generations of stars and planets "“ was forged in the explosions of massive stars. The findings, made with NASA's Spitzer Space Telescope, are the most significant clue yet in the longstanding mystery of where the dust in our very young universe came from. Scientists had suspected that exploding stars, or supernovae, were the primary source, but nobody had been able...

Astronomers have long thought that globular star clusters had a single "baby boom" of stars early in their lives and then settled into a quiet existence. New observations by NASA's Hubble Space Telescope, however, are showing that this idea may be too simple. The Hubble analysis of the massive globular cluster NGC 2808 provides evidence that star birth went "boom, boom, boom," with three generations of stars forming very early in the cluster's life. "We had never...