Newton, the European Space Agency's new X-ray observatory (April p11), was undergoing routine calibration, imaging a known, stable X-ray source in the Large Magellanic Clouds, when all of a sudden, the signal mysteriously disappeared.
LMC X3 is a well known black hole candidate and the cut-off in its X-ray emission is entirely unexpected. X-rays come from the hot gas and dust swirling around the black hole as it is sucked towards the centre.