Introduction
The Classical Nebula Hypothesis explains large-scale collapse and disk formation but does not address the origin of angular momentum or primordial magnetic fields.
Our Self-Sustained Magnetic Dynamo (SSMD) Theory II proposes that proto-Sun convection generates plasma currents, creating a magnetic seed field. This field couples to the ionized nebula, transfers torque, and drives disk rotation.
The framework combines analytic torque estimates, ?–? dynamo modeling, and 3D MHD simulations, anchored by observational data from ALMA, SDO/HMI, JWST, SKA, and Aditya-L1. These provide ~70–75% support for SSMD predictions.

Proto-Sun Evolution Flow:
Nebula (random motions) ? Central condensation ? Rising temperature and pressure ? Ionized proto-Sun plasma ? Plasma currents ? Seed magnetic field ? Lorentz forces (enhanced near poles) ? Circular plasma flow ? Differential rotation (equator ? 25 d, poles ? 35 d) ? Angular momentum transfer ? Formation of a protoplanetary disk.

Figure 1: Schematic of convective currents generating seed magnetic field in proto-Sun

Proto-Sun Convection and Disk Rotation (Short Theory):
In the proto-Sun, vertical convection loops of charged plasma naturally generate circular magnetic fields around each loop. These magnetic fields exert Lorentz forces on surrounding ionized sun plasma and nebula both, producing differential torque: stronger near the poles (slower rotation) and weaker near the equator (faster rotation). As a result, outer plasma is torqued into circular motion around the loop axes, establishing differential rotation in the proto-Sun and initiating early protoplanetary disk formation. This mechanism links interior convection-driven magnetism directly to nebular spin-up and disk alignment.