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A simple trap model of solar hard X-ray bursts is discussed in which nonthermal electrons trapped in a magnetic bottle precipitate into the lower chromosphere through the resonant scattering by whistlers. In -such a model, the X-ray spectra produced from trapped and precipitating electrons have 9 different spectral shape, and both of the spectra will initially soften with time, provided the precipitation dominates over collisional degradation.

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The brightness distribution of the quiet Sun at 8.6 mm wavelength is synthesized from off-meridian observations using an eight element east-west interferometer with a maximum base line of 16.38 m (1913A). The observed brightness distribution is practically flat from the disk center to the optical limb. The effective radius of the nearly uniform component is 1.01 R| If the limb brightening is present, the brightening located between 0.95 R| and 1.01 R| and the total flux density of the limb brightening is less than 1% of the total flux density of the.Sun. In addition to the nearly uniform component there exists a coronal component just outside the optical limb.