Low or intermediate mass stars like our Sun end their lives relatively nonviolently: instead of exploding like supernovae, they expel their outer layers of dust and gas, leaving behind a white dwarf surrounded by a planetary nebula (which has nothing to do with it). planet actually). In several of these environments of intense ultraviolet radiation, theoretically hostile to the elements involved in the formation of life, a water-forming molecule has been found.
Two independent studies, based on the observations of the Herschel space telescope, have confirmed the presence of a fundamental molecule for the formation of water in the vicinity of different planetary nebulae or dying stars . It is the OH + molecule, made up of an oxygen atom and a hydrogen atom, with a positive charge. This not only seems to survive without problems in these conditions, but could even depend on them to form.
Essential chemical elements, such as carbon, nitrogen and oxygen, are not usually present among the rich variety of molecules in the expelled layers of material, since the powerful radiation field destroys their pre-existing molecules and restricts the formation of new ones.
The authors of both studies maintain, however, that the key to the finding lies in the formation of new OH + molecules , the result of the interaction between the dense lumps of dust and gas, and the ultraviolet and X-ray radiation emitted by the fiery White dwarf.
