Wednesday, February 12, 2014

First Gaia Telescope Image

Summary: The telescope Gaia has released its first test image of a star cluster in the Large Magellanic Cloud (LMC). This is only a test image though, Gaia's real job is to track and characterize points of light moving across its big detector. These points of light could be anything from a star, an asteroid, or even flashes of light caused by explosions such as supernovae. The test image simply verified that all the electronics are working and communicating with each other properly.

Gaia will be making a 3D map of a small area of the sky over five years. Ideally, at the end of the mission, it will know the coordinates of the brightest stars to within an error of seven micro-arcseconds. This angle is the same angle as viewing a small coin like a euro on the surface of the moon from earth; incredibly small! Currently, the best precision is to within 1%, and as astronomers try to measure stars farther away, this error will become more noticeable. Gaia will double check our current methods of measurement and help limit the amount of error when measuring other stars. This means that our future measurements can be more accurate and we will be able to, hopefully, have a more accurate estimate of how fast our universe is expanding.


BBC News

Monday, February 3, 2014

BOSS Data

Summary: The BOSS (Baryon Oscillation Spectroscopic Survey) collaboration has released a new report with record precision of 1% and a more accurate measure of w, Dark Energy's pressure to density ratio. If this number is simply Einstein's cosmological constant, then w=-1. The new data seems to provide solid proof for this theory as their results yielded w= -1.03±0.06.

The overall purpose of the collaboration is to more precisely determine the redshift of galaxies so that astronomers can connect this measurement with other measurements of cosmological distance. This correlation can then be applied to galaxies that are too far to measure distance by anything other than redshift.


Physics Today