Supernovae Get Weirder
Observations of Type Ia supernovae are the only evidence of an "accelerating universe." It would be convenient for cosmologists if all Type Ia's were the same, all fireflies had the same luminosity, and all people thought the same. New evidence from the XMM-Newton and Chandra X-ray observatories may force a rethink.
The big photo is a composite of DEM L238 (right) and DEM L249. Chandra X-ray data is blue and optical data is red. The inset shows DEM L238 in low-energy (red), medium energy (green) and high energy X-rays (blue). The central portion of DEM L238 is hot and green, indicating an overabundance of iron.
Iron identifies DEM L238 as a Type Ia supernova. The iron in these supernovae is much denser than in most Type Ia's. That would indicate that the stars were born more massive and exploded as supernovae unusually young. They may represent an entirely new class of supernova.
Type Ia's are thought to result when a white dwarf star abruptly absorbs a companion, pushing it over the Chandrasekhar Limit of 1.4 solar masses. Boom! Chandrasekhar's Limit is proportional to hc/(Gm_p^2). Since the product hc is here considered constant, the limit is not affected by a changing c. Redshift and the energy E=mc^2 are affected, making the universe appear to accelerate.