In the early universe, just a few hundred million years after the Big Bang, astronomers see strange objects — little red dots. They are compact, red, and in their spectra, broad Balmer lines scream the presence of supermassive black holes. But how did the hole manage to accumulate millions of solar masses in such a short time? Standard accretion scenarios require hundreds of millions of years — an impermissible luxury when the universe was only a few hundred million years old. Dusty models try to soften the contradiction, but they look contrived. Enter the cosmic matryoshka: not one object, but a whole nested system where each layer plays its part.

In this dust-free scheme, a supermassive star forms at the galaxy’s center — a gas ball with a mass of millions of Suns. Stars from the surrounding cluster zip through it, braking against the gas and dumping kinetic energy. Turbulent motions in the plasma drive a magnetic reconnection, and the field inflates the envelope to gigantic proportions. Its effective temperature drops to 3100 K, like a red supergiant. Without any dust, a red optical continuum is born. External stars not hidden by the envelope illuminate the system in ultraviolet — giving rise to a V-shaped spectrum. Meanwhile, captured stars sink, collide, and form a dense hot core with virial velocities of 2590 km/s, producing those very broad lines.

The model’s key focus is the growth of the central black hole. It feeds not on its own radiation, but on the global luminosity of the entire envelope. This switches accretion from an exponential to a linear regime and cuts the time to accumulate 10⁷ solar masses to just 67 million years — fitting perfectly within cosmological constraints. The X-ray silence is also explained: the dense envelope serves as a Accretion disk (a Compton-thick screen) where high-energy photons get stuck, never reaching telescopes. So a single self-consistent picture solves several puzzles at once.

Now the model makes testable predictions. The inner core, once formed, should oscillate with periods ranging from months to decades. These oscillations will manifest as spectral variability and line shifts. Spectral monitoring of those very red dots is a prime task for future observations. Thus, the cosmic matryoshka transforms from a hypothesis into a working tool: if we find the predicted pulsations, it will confirm that galaxies at the dawn of time grew their central black holes inside giant stellar cocoons. And then the image of a nested structure will become not just a metaphor, but a precise map of the birth of supermassive black holes.