Waspie_Dwarf Posted September 10, 2014 #1 Share Posted September 10, 2014 This Star Cluster Is Not What It Seems VLT observations of Messier 54 show the lithium problem also applies outside our galaxy This new image from the VLT Survey Telescope at ESO’s Paranal Observatory in northern Chile shows a vast collection of stars, the globular cluster Messier 54. This cluster looks very similar to many others but it has a secret. Messier 54 doesn’t belong to the Milky Way, but is part of a small satellite galaxy, the Sagittarius Dwarf Galaxy. This unusual parentage has now allowed astronomers to use the Very Large Telescope (VLT) to test whether there are also unexpectedly low levels of the element lithium in stars outside the Milky Way.The Milky Way galaxy is orbited by more than 150 globular star clusters, which are balls of hundreds of thousands of old stars dating back to the formation of the galaxy. One of these, along with several others in the constellation of Sagittarius (The Archer), was found in the late eighteenth century by the French comet hunter Charles Messier and given the designation Messier 54. For more than two hundred years after its discovery Messier 54 was thought to be similar to the other Milky Way globulars. But in 1994 it was discovered that it was actually associated with a separate galaxy — the Sagittarius Dwarf Galaxy. It was found to be at a distance of around 90 000 light-years — more than three times as far from Earth as the galactic centre. Read more... Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted September 10, 2014 Author #2 Share Posted September 10, 2014 (edited) Zooming in on the globular star cluster Messier 54This video takes you on a journey past the centre of the Milky Way and far out the other side to the globular cluster Messier 54. This cluster looks very similar to many others, but it has a secret. Messier 54 doesn't belong to the Milky Way, but actually is part of a small satellite galaxy, the Sagittarius Dwarf Galaxy. The final close-up view comes from the VLT Survey Telescope at ESO's Paranal Observatory in northern Chile.Credit: ESO/N. Risinger (skysurvey.org). Music: John DysonSource: ESO Observatory Edited September 10, 2014 by Waspie_Dwarf typo Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted September 10, 2014 Author #3 Share Posted September 10, 2014 (edited) Close-up view of the globular star cluster Messier 54This video gives a close-up view of an image from the VLT Survey Telescope at ESO's Paranal Observatory in northern Chile showing the globular cluster Messier 54. This cluster looks very similar to many others, but it has a secret. Messier 54 doesn't belong to the Milky Way, but actually is part of a small satellite galaxy, the Sagittarius Dwarf Galaxy. This unusual parentage has allowed astronomers to use the Very Large Telescope (VLT) to test whether unexpectedly low levels of the element lithium are also found in stars outside the Milky Way.Credit: ESOSource: ESO Observatory Edited September 10, 2014 by Waspie_Dwarf typo. Link to comment Share on other sites More sharing options...
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