2003MNRAS.341.1388R

We present the results of a search for X-ray variability in the Galactic open cluster NGC 2516. This cluster has been observed on eight occasions using XMM-Newton, making it an excellent target for such a study. We find four sources that show significant variability, implying the detection of one significantly variable source every 25 ks. All sources exhibit spectra that can be fitted using an absorbed one- or two-temperature thermal plasma model. The brightest of these flares also show a prominent iron line near ∼7.0 keV. All four sources lie near the observed main sequence of NGC 2516, suggesting that they are cluster members. We propose that at least three of the four objects are RS CVn systems. We compare the properties of the brightest flare with those of solar flares.