dust in a 4,500-6,500 K temperature environment could be explained by condensations in the low pressure parts of shock fronts - being detected in the atmosphere of RY Sagittarii - a condensation that causes local runaway cooling, allowing carbon dust to form.

The formation of the stars themselves is also unclear. Standard stellar evolution models do not produce large luminous stars with essentially zero hydrogen. The two main theories to explain these stars are both somewhat exotic, perhaps befitting