. Earth Science News .
SKY NIGHTLY
A Swarm Of Ancient Stars

The globular cluster Messier 107, also known as NGC 6171, is located about 21 000 light-years away in the constellation of Ophiuchus. Messier 107 is about 13 arcminutes across, which corresponds to about 80 light-years at its distance. As is typical of globular clusters, a population of thousands of old stars in Messier 107 is densely concentrated into a volume that is only about twenty times the distance between our Sun and its nearest stellar neighbour, Alpha Centauri, across.

This image was created from exposures taken through blue, green and near-infrared filters, using the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at La Silla Observatory, Chile. Credit: ESO/ESO Imaging Survey
by Staff Writers
Paris, France (SPX) Dec 09, 2010
We know of about 150 of the rich collections of old stars called globular clusters that orbit our galaxy, the Milky Way. This sharp new image of Messier 107, captured by the Wide Field Imager on the 2.2-metre telescope at ESO's La Silla Observatory in Chile, displays the structure of one such globular cluster in exquisite detail.

Studying these stellar swarms has revealed much about the history of our galaxy and how stars evolve.

The globular cluster Messier 107, also known as NGC 6171, is a compact and ancient family of stars that lies about 21 000 light-years away. Messier 107 is a bustling metropolis: thousands of stars in globular clusters like this one are concentrated into a space that is only about twenty times the distance between our Sun and its nearest stellar neighbour, Alpha Centauri, across. A significant number of these stars have already evolved into red giants, one of the last stages of a star's life, and have a yellowish colour in this image.

Globular clusters are among the oldest objects in the Universe. And since the stars within a globular cluster formed from the same cloud of interstellar matter at roughly the same time - typically over 10 billion years ago - they are all low-mass stars, as lightweights burn their hydrogen fuel supply much more slowly than stellar behemoths.

Globular clusters formed during the earliest stages in the formation of their host galaxies and therefore studying these objects can give significant insights into how galaxies, and their component stars, evolve.

Messier 107 has undergone intensive observations, being one of the 160 stellar fields that was selected for the Pre-FLAMES Survey - a preliminary survey conducted between 1999 and 2002 using the 2.2-metre telescope at ESO's La Silla Observatory in Chile, to find suitable stars for follow-up observations with the VLT's spectroscopic instrument FLAMES .

Using FLAMES, it is possible to observe up to 130 targets at the same time, making it particularly well suited to the spectroscopic study of densely populated stellar fields, such as globular clusters.

M107 is not visible to the naked eye, but, with an apparent magnitude of about eight, it can easily be observed from a dark site with binoculars or a small telescope. The globular cluster is about 13 arcminutes across, which corresponds to about 80 light-years at its distance, and it is found in the constellation of Ophiuchus, north of the pincers of Scorpius.

Roughly half of the Milky Way's known globular clusters are actually found in the constellations of Sagittarius, Scorpius and Ophiuchus, in the general direction of the centre of the Milky Way. This is because they are all in elongated orbits around the central region and are on average most likely to be seen in this direction.

Messier 107 was discovered by Pierre Mechain in April 1782 and it was added to the list of seven Additional Messier Objects that were originally not included in the final version of Messier's catalogue, which was published the previous year.

On 12 May 1793, it was independently rediscovered by William Herschel, who was able to resolve this globular cluster into stars for the first time. But it was not until 1947 that this globular cluster finally took its place in Messier's catalogue as M107, making it the most recent star cluster to be added to this famous list.

This image is composed from exposures taken through the blue, green and near-infrared filters by the Wide Field Camera (WFI) on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile.



Share This Article With Planet Earth
del.icio.usdel.icio.us DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook



Related Links
ESO
Astronomy News from Skynightly.com



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


SKY NIGHTLY
Discovery Triples Number of Stars In Universe
New Haven CT (SPX) Dec 02, 2010
Astronomers have discovered that small, dim stars known as red dwarfs are much more prolific than previously thought - so much so that the total number of stars in the universe is likely three times bigger than realized. Because red dwarfs are relatively small and dim compared to stars like our Sun, astronomers hadn't been able to detect them in galaxies other than our own Milky Way and it ... read more







SKY NIGHTLY
Flood-swept Czech town turns disaster into development

Facebook co-founders pledge wealth to charity

Britain to outsource search-and-rescue ops

Colombia mudslide toll rises to 46 dead

SKY NIGHTLY
Sony and Sharp launch e-readers, tablets in Japan

World's First Microlaser Emitting In 3-D

EU slaps huge fine on South Korea, Taiwan LCD cartel

Google says 300,000 Android phones activated daily

SKY NIGHTLY
Conditioning Reefs For The Future

Mobile 'revolution' eases Pacific isolation, poverty

EU 'loophole' allows shark finning

Laos inaugurates controversial hydropower dam

SKY NIGHTLY
Greenland Ice Sheet Flow Driven By Short-Term Weather Extremes Not Gradual Warming

It's Time For Europe To Step Up Research In The Polar Regions

Glaciers melting fastest in South America, Alaska: UN

New Research Shows Rivers Cut Deep Notches In The Alps' Broad Glacial Valleys

SKY NIGHTLY
New Discovery About How Flowering Time Of Plants Can Be Controlled

Argentine shepherds, farmers protect forests from soy

Plants Remember Winter To Bloom In Spring With Help Of Special Molecule

Shanghai halts sale of suspected 'dyed' oranges: report

SKY NIGHTLY
Latin America counts the cost after deadly rains

More than 11,000 people evacuated in Albania floods

Ecuador downgrades active volcano warning

Rains leave rising death toll in Colombia, Venezuela

SKY NIGHTLY
Gbagbo's rivals demand backing of I.Coast military

Leaked US cable says China has 'no morals' in Africa

Sudan heads toward breakup

Conservationists seek legal freeze of Tanzania road

SKY NIGHTLY
Lost Civilization Under Persian Gulf

Babies' Biological Clocks Dramatically Affected By Birth Light Cycle

Seeing The World All Depends On Differen Visual Minds

Apes Unwilling To Gamble When Odds Are Uncertain


The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement