094054

Chromospheric activity cycles have been detected in solar type stars howeververy few cases are known in X-rays. This proposal is meant to establish a longterm monitoring of solar type starsin order to detect any activity cycles. The sample is composed by solar typestars spanning different ages masses activity level in chromosphere andcoronae and hosting transiting planets. The atmospheres of these planets willbe studied in details by ESA Ariel mission. Our purpose is to establish now morecases of X-ray cycles and to better understand the effects of the modulation ofX-ray cycles on the photo-evaporation and the photochemistry of the planetaryatmospheres. [truncated! Please see actual data for full text]