South Skies Finally Mapped

Surprisingly, the skies over the southern hemisphere of the Earth have never been scoured in great detail, such as the Sloan Digital Sky Survey has done for the northern regions. As such, the knowledge scale is heavily tilted towards the celestial objects of the north. This issue had to be addressed, especially since the southern hemisphere hosts a large series of interesting items and events that are already known and need to be studied, but it may even be home to some surprises. This is what a new project, named SkyMapper, attempts to solve.

Among the objectives set by the specialists are: observing certain types of stars, such as some that could provide insight on the Milky Way's past gobbling of a dwarf galaxy, new dwarf galaxies orbiting or part of our own, as well as obtaining a more detailed image of the center of our galaxy. The SkyMapper is the Siding Spring Mountain, New South Wales, Australian equivalent of the Sloan telescope located in Sunspot, New Mexico, only better, as the project's chief, Brian Schmidt, states.

 

SkyMapper is provided with a 1.35 meter telescope and a 268-Megapixel camera that will help it survey the south skies for about five years, starting next April. It will scan the heavens six times, each time in six different colors. Comparing to Sloan, it has two ultraviolet filters instead of just one, which will enable it to infer the metal amount in a star, as well as its gravitational strength. This could yield the discovery of about 300 'metal poor' stars (with 10,000 times less iron than the Sun).

 

"They're the ones that were clearly created just after the big bang, because they haven't been contaminated with any products of supernovae," shares Schmidt, an astrophysicist at the Australian National University's Mount Stromlo Observatory, as cited by New Scientist. These would in turn provide hints on the fact that dark matter could actually be comprised of light, fast particles. The experts also hope to find hypervelocity stars and determine whether they were thrown away by the Milky Way's black hole or captured from a swallowed dwarf galaxy.