TEMPERATURE MAPPING OF SUNSPOTS AND PORES FROM SPECKLE RECONSTRUCTED 3 COLOR PHOTOMETRY

The two-dimensional temperature distribution in a highly structured su nspot and in two small umbrae is determined from a three-colour photom etry in narrow spectral continua. Disturbing influences from the earth 's atmosphere are removed by speckle masking techniques, yielding a sp atial resolution limited by the telescope's aperture. The correspondin g colour temperatures are consistent over a range of more than 2000K, although the numerical correction introduced by the reconstruction dif fers largely for the three colours. Part of the scatter in the tempera ture relation disappears when convoluting the final images with artifi cial PSFs that compensate for the different, colour dependent spatial resolution. The remaining spread in the scatter plots does not reflect noise, but is related to local variations of the temperature differen ce between the continuum emitting layers. This is most obvious for a s mall umbra which yields 'branches' in the scatter plots the 'bluer' of which corresponding to the limb-side umbral border. Here, the 'hot ri m' of a Wilson depressed umbra becomes visible. The temperature map of the large spot shows that the bright umbral dots do not reach the tem perature of the non-spot surroundings. Instead, they exceed the 2000 K cooler umbral temperature minimum by 900-1300 K. The filamentary stru cture of the surrounding penumbra has spatial temperature fluctuations of typically 700 K, a value which fits earlier observed contrasts. Ho wever, the mean temperatures of 5650 K in the dark and 6250 K in the b right penumbral fine structures exceed former findings. Exceptionally bright penumbral grains are 250 K hotter than the mean solar surface a nd thus exceed even brightest granules.