I didn't go to university <a href=" http://iibf.uludag.edu.tr/?buy-metformin-1000-mg-online.pdf ">metformin online order</a> Some experts aren&rsquo;t convinced that the oxygen found on the surface of the white dwarf is a clear sign that water existed on an orbiting asteroid, however. &ldquo;The link of the pollution of a white dwarf to the inventory of water in an earlier planetary system is a very interesting scientific question still under investigation,&rdquo; says exoplanet researcher Lisa Kaltenegger of Harvard University and the Max Planck Institute for Astronomy in Germany, who was not involved in the research. Claire Moutou, another exoplanet specialist at the Laboratory of Astrophysicsof Marseille in France, agreed. &ldquo;I find the analysis/conclusions of the paper reasonable, as far as the amount of oxygen available to lie in H2O molecules is concerned. The interpretation of the origin of this water content is more speculative.&rdquo;