In astronomy, an iron star is a hypothetical type of compact star that could occur in the universe in 101500 years. The premise behind iron stars states that cold fusion occurring via quantum tunnelling would cause the light nuclei in ordinary matter to fuse into iron-56 nuclei. Fission and alpha-particle emission would then make heavy nuclei decay into iron, converting stellar-mass objects to cold spheres of iron. The formation of these stars is only a possibility if the proton does not decay. Though the surface of a neutron star may be iron, according to some predictions, it is distinct from an iron star.
The term is also used for blue supergiants which have a forest of forbidden FeII lines in their spectra. They are potentially quiescent hot luminous blue variables. Eta Carinae has been described as a prototypical example.
In popular culture
- Soviet film The Andromeda Nebula: Episode I. Prisoners of the Iron Star is about a starship low on fuel caught by gravity of an iron star, which could only be seen in the infrared. It is based on the novel Andromeda: A Space-Age Tale by Ivan Yefremov written when Steady State theory was dominant and iron stars were expected to exist in our galaxy.
- Dyson, Freeman J. (1979). "Time without end: Physics and biology in an open universe". Reviews of Modern Physics. 51 (3): 447–460. Bibcode:1979RvMP...51..447D. doi:10.1103/RevModPhys.51.447.
- Walborn, Nolan R.; Fitzpatrick, Edward L. (2000). "The OB Zoo: A Digital Atlas of Peculiar Spectra". The Publications of the Astronomical Society of the Pacific. 112 (767): 50. Bibcode:2000PASP..112...50W. doi:10.1086/316490.
- Clark, J. S.; Castro, N.; Garcia, M.; Herrero, A.; Najarro, F.; Negueruela, I.; Ritchie, B. W.; Smith, K. T. (2012). "On the nature of candidate luminous blue variables in M 33". Astronomy & Astrophysics. 541: A146. arXiv:. Bibcode:2012A&A...541A.146C. doi:10.1051/0004-6361/201118440.