Depending on its initial mass, it might collapse to a compact hot star known as a white dwarf (when the star's mass is less than 1.4 times the mass of our sun) or to a neutron star (for stars 1.4 to about three times the mass of our sun) or to a black hole (for stars more massive than three times the mass of our sun).

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Glaxo provided the initial funding and holds a controlling stake, but the Cambridge, Mass. startup runs independently.

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Dr Tongesayi told BBC News he was determined to reconcile his initial findings with the outcomes of subsequent analyses of his samples by other means, including the mass spectrometry method.

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