Astronomy

from http://www.cosmosmagazine.com/news/2156/milky-way-map-shows-complex-outer-galaxy

SYDNEY: The Milky Way is encircled by streams of stars in shapes resembling a “jumble of pasta” according to scientists examining data from the biggest survey ever made of our galaxy.

The sky was mapped by the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey, which will ultimately create a detailed 3-dimensional map of the galaxy, featuring 240,000 stars.

Ripped apart

The survey has revealed new details of streams of stars that wrap around our galaxy. Astronomers found 14 distinct stream structures, 11 of them previously unknown. Many are believed to be dwarf galaxies on the margins of the Milky Way that were ripped apart by the gravity of their larger companion.

Kevin Schlaufman, lead astrophysicist behind the work at the University of California, Santa Cruz, said the new discoveries were just a small fraction of the mysterious structures waiting to be found within the Milky Way’s more than 100 billion stars.

"Even with SEGUE, we are still only mapping a small fraction of the Galaxy, so 14 streams in our data implies a huge number when we extrapolate to the rest of the Milky Way," he said.

The SEGUE project is part of the ambitious Sloan Digital Sky Survey (SDSS), being conducted by the 2.5-metre telescope at the Apache Point Observatory in New Mexico, USA. Schlaufman presented the results of the project earlier this month at the SDSS symposium in Chicago, Illinois.