MORE QUALMS ABOUT EXTRASOLAR PLANET DISCOVERIES. The presence of planets around a number of stars has been inferred from the slight doppler wobble in the stars' spectra. One critic, David Grey of the University of Western Ontario, contends that the wobble, at least in the case of the star 51 Pegasi, may be due to the unstable nature of the star itself (Nature, 27 February). A second reservation has since surfaced. Caltech scientists, using an interferometer, suspect that 51 Pegasi is really a binary star system, and that this would account for the wobble (Science, 30 May).