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Posts Tagged ‘Leo’

Galaxy Cluster Hidden in Plain View

March 8, 2012 1 comment

A team of astronomers has discovered the most distant cluster of red galaxies ever observed using FourStar, a new and powerful near-infrared camera on the 6.5m Magellan Baade Telescope. The galaxy cluster is located 10.5 billion light years away in the direction of the constellation Leo. It is made up of 30 galaxies packed closely together, forming the earliest known “galaxy city” in the universe. The findings will be published in the Astrophysical Journal Letters.

Remarkably, the cluster was completely missed by previous surveys, which searched this region of the sky for thousands of hours and were conducted by all the major ground- and space-based observing facilities, including the Hubble Space Telescope. Despite these intense observations, accurate distances for such faint and distant galaxies were missing until the advent of FourStar.

Eric Persson of the Carnegie Observatories* led the development of the new camera that enabled these observations. Persson and his team–which includes Carnegie’s David Murphy, Andy Monson, Dan Kelson, Pat McCarthy, and Ryan Quadri–equipped FourStar with five special filters to collect images that are sensitive to narrow slices of the near-infrared spectrum. This powerful approach allows them to measure accurate distances between Earth and thousands of distant galaxies at one time, providing a 3-D map of the early universe.

Full Story: http://carnegiescience.edu/news/galaxy_cluster_hidden_plain_view

Giant Star Expels Multiple Dust Shells, Researchers Find

September 28, 2011 Leave a comment

An international team led by Leen Decin, a K.U.Leuven astronomer, has discovered a series of dust shells in the vicinity of CW Leonis, a dying giant star. The star expelled the shells in the course of its long life: the most distant shell was expelled 16,000 years ago and, in that time, has drifted more than 7,000 billion kilometres from the star.

CW Leonis is an evolved star in the Leo constellation, 500 light-years from Earth. The dying star has become a carbon-rich red giant star: “Until recently, it was thought that giant star’s surroundings were homogenous: evenly distributed matter without any exceptionally large clumps, but there are more and more indicators suggesting that this is not a reliable picture,” says Leen Decin. “New images from the Herschel satellite confirm this in a spectacular way: We discovered more than a dozen shells expelled throughout the star’s life as a giant. The weakest shell we found is 7,000 billion kilometres from the star.”

Full Story: http://www.astronews.us/2011-09-28-0230.html

The Star That Should Not Exist

September 1, 2011 Leave a comment

A star that should not exist

Image Credit: ESO/Digitized Sky Survey 2

A team of European astronomers has used ESO’s Very Large Telescope (VLT) to track down a star in the Milky Way that many thought was impossible. They discovered that this star is composed almost entirely of hydrogen and helium, with only remarkably small amounts of other chemical elements in it. This intriguing composition places it in the “forbidden zone” of a widely accepted theory of star formation, meaning that it should never have come into existence in the first place. The results will appear in the 1 September 2011 issue of the journal Nature.

A faint star in the constellation of Leo (The Lion), called SDSS J102915+172927, has been found to have the lowest amount of elements heavier than helium (what astronomers call “metals”) of all stars yet studied. It has a mass smaller than that of the Sun and is probably more than 13 billion years old.

Full Story: http://www.eso.org/public/news/eso1132/