X-ray observations of the transits (HD 189733b again !!)

http://spaceref.com/exoplanets/nasa-x-ray-telescope-observes-planet-passing-in-front-of-its-star-for-the-first-time.html

For the first time since exoplanets, or planets around stars other than the sun, were discovered almost 20 years ago, X-ray observations have detected an exoplanet passing in front of its parent star.
An advantageous alignment of a planet and its parent star in the system HD 189733, which is 63 light-years from Earth, enabled NASA's Chandra X-ray Observatory and the European Space Agency's XMM Newton Observatory to observe a dip in X-ray intensity as the planet transited the star.


Paper on arXiv :
http://arxiv.org/abs/1306.2311