Swift detection of the brightest X-ray flare from S50716+714

On 28 April 2008 Swift detected the blazar S50716+714 at X-ray and UV flux levels significantly larger than ever observed before. An analysis of the XRT data gives a 0.3-10 keV X-ray flux of 4e-11 erg/cm2/s, about 50% larger than that observed at the peak of the giant X-ray flare of October-November 2007. Swift will continue the monitoring of S50716+714 over the next few days, while the AGILE Gamma-ray observatory will include this source within its field of view between April 30 and May 10, 2008.