Two alternative methods for evaluating the probability densities of structures defined by d degrees of freedom in random fields are presented. For Gaussian random fields, both differentiable and nondifferentiable, the application of these methods is considered in detail. The relationship between structures, maxima, and connected regions above a

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Results of high-resolution optical spectroscopy of V404 Cyg (the optical counterpart of the X-ray transient GS2023 + 338), conducted 13 months after the May 1989 outburst are presented. The double-peaked H-alpha line exhibits a strong S-wave modulation from which a periodicity of 5.7 hr is deduced. The level of the continuum is also modulated on

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IAUC 5479 available at Central Bureau for Astronomical Telegrams.