Put-puts in the sky. Astronomers looking in the X-ray band have been observing some very strange bursts coming from what are presumed to be binary systems with a closely bound neutron star partner.
The current explanation is that these burps of energy occur as hydrogen and helium stripped from the partner's surface settle onto the neutron star's surface, and when a sufficient amount has accumulated to give the right pressure/temperature combination, it then ignites a thermonuclear reaction to form carbon. These bursts last only fractions of a second, and radiate a large amount of energy that is visible. However, it is the next stage that is of interest: these carbon ashes in turn accumulate, and mix with much of the pre-existing material in the star, including heavier elements. Calculations indicate that a several hundred-meter thick layer can accumulate before it too meets the right conditions for this enriched carbon mixture to 'burn,' producing iron. Apparently this takes only a few tens of years, so there is a good possibility of seeing a repeat event from a previously observed neutron burst.
These 'neutron star superbursts' are quite small compared to grand cosmic events like novae or supernovae, but they reflect the same basic process - a star's matter is crushed between gravity's attraction and the out-fleeing radiation from thermonuclear processes below, which leads to thermonuclear ignition and the production of heavier elements. In the case of novae, the runaway reactions that are so violent they blow the outer layers completely off the star, but in the case of neutron stars, the combustible material runs out quickly, and all that is ejected is a strong pulse of radiation, including the X-rays we have detected here on Earth.
Because of the fact that no material is ejected, there is a lesser chance that we all have some atoms inside our bodies from this kind of process, compared to the novae-produced heavy elements. But not impossible.
