Sunday, July 6, 2008



Credit: ESA/C. Carreau's impression of a rare type of quasar, called a broad absorption line (BAL) quasar. See animation.

Please, PLEASE, do not call it a star. It's a QUASAR! :-)

Quasars are celestial objects that are vast cosmic engines that pump energy into their surroundings. It is thought an enormous black hole drives each quasar and that they form the basis for the creation of galaxies. Hence many orders of magnitude bigger than any star!

Quasars are difficult to see because they are so distant. The light and X-rays from them takes thousands of millions of years to reach us. This is however the reason why we chose these celestial object to define our geodetic reference frame - or intertial coordinate system. The before mentioned VLBI or Radio Telescopes are used to observe the quasars for that purpose, whereas the in-depth study of the quasars is done with the European X-Ray satellite telescope XMM Newton.

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