The Ursa Minor dwarf spheroidal shows a pronounced secondary density peak and other clumpy stellar substructures that appear kinematically cold and long-lived (Kleyna 2003; Pace 2014; Lora 2012; Bullock & Boylan-Kolchin 2017). In ΛCDM, such cold clumps should be rapidly sheared out or heated and dissolved if Ursa Minor sits in a cuspy subhalo-rich CDM potential. Their persistence points toward a large nearly harmonic central core and a smoother halo than standard simulations predict.
The standard model has dwarf spheroidals embedded in cuspy CDM halos with abundant subhalo populations. Long-lived cold stellar clumps demand either large constant-density CDM cores (difficult to produce in cuspy CDM simulations) or modified non-CDM physics. The model has no clean source for the observed substructure persistence.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, Ursa Minor's structural anomalies are predicted cascade-debris substructure preserved by the smoother coherent-mesh halo. With no CDM particles to provide cuspy substructure or to drive shear-and-heating processes (P50, P51, P52, P54), the cold stellar clumps inherited at cascade-deposition can persist for many crossing times without disrupting.
The cored mesh-halo profile (no cuspy NFW center) provides the nearly harmonic central potential that observations infer from Ursa Minor's stellar-kinematic structure. Cascade-debris substructure (P22, P25, P31, P32) deposited multiple cold stellar overdensities at deposition; the lack of CDM-subhalo perturbations preserves them over Gyr timescales. Angular-momentum inheritance (P31, P32) gives the orbital structure of the secondary peak relative to the main body.
Pre-existing matter (P25) gives the stellar diversity across the substructures (different cascade-stream-event chemical baselines for different clumps). The same M6 framework that resolves the Fornax 3 timing problem (recid 146), the broader satellite-system structural anomalies, and the no-DM-particle dynamics of dwarfs (recid 144) accounts for Ursa Minor's substructure persistence. There is no need for special CDM-core formation mechanisms or modified gravity.
If precision Gaia + JWST Ursa Minor mapping demands a CDM-particle cuspy halo with abundant subhalos at the ΛCDM-predicted level (no smooth-mesh signature, no cascade-debris substructure preservation), the M6 no-DM-particle explanation is refuted. The signature SCT prediction is the substructures persisting indefinitely with no CDM-subhalo flyby disturbance.