CoRoT-2 is one of the most unusual planetary systems known to date .
Its host star is exceptionally active , showing a pronounced , regular pattern of optical variability caused by magnetic activity .
The transiting hot Jupiter , CoRoT-2b , shows one of the largest known radius anomalies .
We analyze the properties and activity of CoRoT-2A in the optical and X-ray regime by means of a high-quality UVES spectrum and a 15 ks Chandra exposure both obtained during planetary transits .
The UVES data are analyzed using various complementary methods of high-resolution stellar spectroscopy .
We characterize the photosphere of the host star by deriving accurate stellar parameters such as effective temperature , surface gravity , and abundances .
Signatures of stellar activity , Li abundance , and interstellar absorption are investigated to provide constraints on the age and distance of CoRoT-2 .
Furthermore , our UVES data confirm the presence of a late-type stellar companion to CoRoT-2A that is gravitationally bound to the system .
The Chandra data provide a clear detection of coronal X-ray emission from CoRoT-2A , for which we obtain an X-ray luminosity of 1.9 \times 10 ^ { 29 } erg s ^ { -1 } .
The potential stellar companion remains undetected in X-rays .
Our results indicate that the distance to the CoRoT-2 system is \approx 270 pc , and the most likely age lies between 100 and 300 Ma .
Our X-ray observations show that the planet is immersed in an intense field of high-energy radiation .
Surprisingly , CoRoT-2A ’ s likely coeval stellar companion , which we find to be of late-K spectral type , remains X-ray dark .
Yet , as a potential third body in the system , the companion could account for CoRoT-2b ’ s slightly eccentric orbit .