Top panel: interferometric observations of the surface of Betelgeuse obtained with the William Herschel Telescope at a wavelength of 710 nm, in January 1991 (Wilson et al. 1992) and January 1992 (Tuthill et al. 1997). North is at the top and East is to the left. The two images have been taken from Freytag et al. (2002). The spot properties are summarised in Table 1. Bottom panel: Hipparcos epoch photometry of Betelgeuse with the vertical lines indicating the epoch of the two interferometric observations.