Tuesday, 22 February 2011

An exquisite new instrument for listening to the Music of the Spheres

This week, the remarkable Kepler spacecraft has been in the news for the fascinating new research it is generating in detecting the size and age of stars. Kepler is using a technique that scientists dub "asteroseismology" to measure minuscule variations in a star's brightness that occur as sound-waves bounce within it.

Dr Bill Chaplin, Reader in Solar and Stellar Physics, from the University of Birmingham's School of Physics and Astronomy, spoke at the American Association for the Advancement of Science conference on Saturday 19 February 2011, giving an overview of results on the study of solar-type stars using the science of asteroseismology.

Asteroseismology is the observation of the natural resonances, or pulsations, of stars. Using the data from these oscillations, collected by the NASA Kepler spacecraft, it is possible to measure the ages and sizes of stars, and to map out their interiors with hitherto unknown precision. The Kepler Mission is primarily used to look for extrasolar planets - planets that are outside our solar system orbiting other stars, but this new finding is one of the most significant pieces of research is has yielded in recent times.

Chaplin told the conference that asteroseismology was, in essence, listening to the "music of the stars" - a somewhat poetically apt reference, given that the Kepler craft is named after the 17th century German mathematician and astronomer, Johannes Kepler who reinvigorated Pythagorus notion of the"music of the spheres".

For some time, I have been researching how radio astronomy, when used as an instrument of audification, can enable us to move closer to the "music of the spheres" (http://radioqualia.va.com.au/honor/research.html). But astroseismology is proving to be an equally powerful instrument in helping us appreciate the sonic character of our universe.


Network of radio astronomy dishes redrawing the map of our galaxy

It's been a big week for astronomy, with important new data revealing the scale of both stars and planets.

Science Daily reports on how the continent-wide Very Long Baseline Array (VLBA) - an international network of radio astronomy facilities - is redrawing the map of our home galaxy and is poised to yield tantalizing new information about extrasolar planets. Their work also has important implications for numerous areas of astrophysics, including determining the nature of dark energy, which constitutes 70 percent of the Universe.

"Solving the Dark Energy problem requires advancing the precision of cosmic distance measurements, and we are working to refine our observations and extend our methods to more galaxies," said James Braatz, of the National Radio Astronomy Observatory (NRAO).

The project uses the VLBA along with NRAO's Green Bank radio astronomy telescope in West Virginia, the largest fully-steerable dish antenna in the world. The VLBA, dedicated in 1993, uses ten, 25-meter-diameter dish antennas distributed from Hawaii to St. Croix in the Caribbean. All ten antennas work together as a single telescope with the greatest resolving power available to astronomy. Together, these telescopes can detect the faint radio emission from the stars to track their motion over time. This unique capability has produced landmark contributions to numerous scientific fields, ranging from Earth tectonics, climate research, and spacecraft navigation to cosmology.

Source: http://www.sciencedaily.com