High resolution solar images at 10 microns: Sunspot details and photometry

A slow raster scanning device and a germanium bolometer are used to record two dimensional photometric information in the 9–12 μ region; the results can be displayed on a CRT to get real 10 μ photographs of the upper photosphere (τ ₅₀₀₀ ～- 0.1) with a spatial resolution of 2 arc sec. Comparison with simultaneously obtained visible CRT photographs shows a significant improvement of atmospheric seeing at long wavelengths. Bright, small (unresolved?) points are observed around sunspots at 10 μ and may be related to the so-called ‘moustaches’ observed in the wings of strong lines. Umbral intensities are derived from the data and compared to various sunspots models.