The radio emission from the youngest known Planetary nebula, SAO244567, has been mapped at 1384, 2368, 4800, 8640, 16832 and 18752 MHz by using the Australian Telescope Compact Array (ATCA). These observations constitute the first detailed radio study of this very interesting object, as they allow us to obtain the overall radio morphology of the source and to compute, for the first time, the radio spectrum up to millimetre range. Radio emission is consistent with free-free from a wind-like shell, which is also the region where most of the [OIII] comes from as revealed by HST images. Physical parameters of the radio nebula and of the central star were derived, all consistent with SAO 244567 being a very young Planetary Nebula still embedded in the dusty remnant of the AGB phase. The optically thin radio flux density appear to decrease when compared to data from the literature. Even very appealing, the variability of the radio emission, probably related to the evolution of the central object, needs further investigations.
تحميل البحث