Superluminous Supernovae No Threat From Eta Carinae

Abstract

Recently Supernova 2006gy was noted as the most luminous ever recorded, with a total radiated energy of -10(44) Joules. It was proposed that the progenitor may have been a massive evolved star similar to n Carinae, which resides in our own galaxy at a distance of about 2.3 kpc. n Carinae appears ready to detonate. Although it is too distant to pose a serious threat as a normal supenova, and given its rotation axis is unlikely to produce a Gamma-Ray Burst oriented toward the Earth, n Carinae is about 30,000 times nearer than 2006gy, and we re-evaluate it as a potential superluminous supernova. We find that given the large ratio of emission in the optical to the X-ray, atmospheric effects are negligible. ionization of the atmosphere and concomitant ozone depletion are unlikely to be important. Any cosmic ray effects should be spread out over ~10(4)y, and similarly unlikely to produce any serious perturbation to the biosphere. We also discuss a new possible effect of supernovae, endocrine disruption induced by blue light near the peak of the optical spectrum. this is a possibility for nearby supernovae at distances too large to be considered "dangerous" for other reasons. However, due to reddening and extinction by the interstellar medium, n Carinae is unlikely to trigger such effects to any significant degree.