Blue Transient Shocks

A class of rapidly evolving, blue-optical transients has been identified in wide-field survey data that does not fit comfortably into any standard stellar explosion category. These events rise and fade on timescales of days rather than weeks, exhibit blue continuum spectra at peak inconsistent with photospheric thermal emission from standard core-collapse or thermonuclear supernovae, and often lack the hydrogen and helium features expected from common progenitor systems. Their volumetric rate appears to be non-negligible, and their host galaxy distribution — preferring low-metallicity star-forming galaxies — suggests a connection to an early-universe or low-metallicity stellar population. ΛCDM-based stellar evolution models struggle to identify a single well-defined progenitor channel that produces the observed rate, timescale, and spectral properties simultaneously.

Successive Collision Theory links blue transient shocks to the pre-existing compact object populations inherited from the colliding spacetime pockets. The debris field from the superluminal collision thermalized the pre-existing stellar content of both pockets, but not all compact objects were fully disrupted — dense remnants including neutron stars, white dwarfs, and the cores of evolved massive stars survived the thermalization epoch and were incorporated into the post-collision debris as a population of compact objects with non-standard metallicities and orbital configurations. When these pre-existing compact remnants subsequently accreted debris material or underwent dynamical interactions in the early post-collision environment, they produced energetic transient events with rise times and spectral temperatures set by the compact object's radius and accretion timescale rather than by the envelope structure of a standard stellar progenitor.

The blue spectral character of these transients in SCT reflects the high effective temperature of shock-heated material impacting or erupting from compact objects with radii orders of magnitude smaller than main-sequence stellar envelopes. The angular momentum inherited from the collision deposits material in highly eccentric orbits around these compact remnants, producing recurrent accretion outbursts when the orbital periapsis is small. The low-metallicity host galaxy preference follows naturally because pre-existing compact objects that survived the thermalization epoch are most easily identified in galaxies that have not yet been substantially enriched by post-collision stellar evolution, preserving the chemical signature of the pre-collision epoch in the local interstellar medium.