Published online by Cambridge University Press: 19 April 2010
Extrasolar planet searches blossomed and prospered under the auspices of the radial velocity method. However, efficient as it is, it can misinterpret a periodic signal created by stellar phenomena as being originated from a planet. The most common of these is the presence of a cold spot, frequent in active stars. Here we review the representative cases of HD 166435, GJ 674 and TW Hya and the different methods used to pinpoint the spots' presence. We finish by underlining the importance of infrared measurements, as done in the TW Hya campaign, as a way of reducing the effect of spots on radial velocity measurements to a negligible level.