Activity cycles are commonly found among late type stars through the chromospheric Ca II emission. Their coronal counterpart, however, remains elusive in most cases, despite of the clear X-ray cycle observed in the solar corona, spanning as much as 1.7 dex in L x . The recent discovery of a Ca II cycle in iota Hor of just 1.6 yr, the shortest to date, offered us a unique opportunity to monitor its X-ray counterpart in short time. The star offers also two more interesting properties: a planet of ~1.9 MJ orbits the star at 0.9 a.u., and with an age of only ~600 Myr and spectral type F8V, ι Hor represents a young solar analog, so its cycle might be the paradigm of the first activity cycles in the life of a solar-like star. Our XMM-Newton observations show the first coronal cycle in a single star. In good agreement with Ca II contemporaneous observations, the long term XMM-Newton light curve suggests also a long-term trend that seems to modulate the 1.6 yr cycle. Iota Hor may offer us the unique possibility to observe for the first time a double coronal cycle similar to those observed in the chromosphere of other stars.

{"references": ["Ayres, T. R. 2009, ApJ, 696, 1931", "Ayres, T. R. 2014, AJ, 147, 59", "B\u00f6hm-Vitense, E. 2007, ApJ, 657, 486", "Favata, F., Micela, G., Baliunas, S. L., et al. 2004, A&A, 418, L13", "Favata, F., Micela, G., Orlando, S., et al. 2008, A&A, 490, 1121", "G\u00fcdel, M. 2004, A&ARv, 12, 71", "Hempelmann, A., Robrade, J., Schmitt, J. H. M. M., et al. 2006, A&A, 460, 261", "Judge, P. G., Solomon, S. C., & Ayres, T. R. 2003, ApJ, 593, 534", "Lalitha, S.; Schmitt, J. H. M. M. 2013, A&A, 559, 119", "Lorente, R., & Montesinos, B. 2005, ApJ, 632, 1104", "Metcalfe, T. S., Basu, S., Henry, T. J., et al. 2010, ApJ, 723, L213", "Orlando, S., Peres, G., & Reale, F. 2001, ApJ, 560, 499", "Robrade, J., Schmitt, J. H. M. M., & Favata, F. 2005, A&A, 442, 315", "Robrade, J., Schmitt, J. H. M. M., & Favata, F. 2012, A&A, 543, A84", "Sanz-Forcada, J.; Maggio, A.; Micela, G. 2003, A&A, 408, 1087", "Sanz-Forcada, J.; Stelzer, B.; Metcalfe, T. S. 2013, A&A, 553, L6"]}

Poster #227