The spectrum of the planetary nebula NGC 6302 is presented, as it was observed by the ISO short-wavelength spectrometer. The IUE spectrum observed at the same position with the same aperture is also presented.

It is argued that photochemical processes, driven by ultraviolet starlight, could lead to large deuterium fractionation for H2O and CH4 relative to H2 in the primitive solar nebula. Implications for deuterium enrichment observed in planetary atmospheres are briefly discussed.

According to the planetary origin conceptual model proposed in this paper, the protosun centre of the pre-solar nebula exploded, resulting in a shock wave that passed through it and then returned to the centre, generating a new explosion and shock wave. Recurrent explosions in the nebula resulted in a spherical standing sound wave, whose antinodes concentrated dust into rotating rings that tran...

IC 4406 is a large (about 100 × 30) southern bipolar planetary nebula, composed of two elongated lobes extending from a bright central region, where there is evidence for the presence of a large torus of gas and dust. We show new observations of this source performed with IRAC (Spitzer Space Telescope) and the Australia Telescope Compact Array. The radio maps show that the flux from the ionized...

Received ; accepted – 2 – ABSTRACT We report high resolution (2.5 ′′) CO J=1−0 line imaging which confirms the presence of a molecular disk around the origin of the spectacular, 14 ′ × 4 ′ , episodic jets in the planetary nebula KjPn 8. The disk is 30 ′′ in diameter with an expansion velocity of ≈ 7 km s −1. The axis of the disk is aligned with the youngest and fastest (≈ 300 km s −1) of the bi...