The timescales you mentioned are related to different phenomena and should not be directly compared. Let's break down the two scenarios:
Transparency of the Universe: The 375,000 years you mentioned refers to the time it took for the universe to become transparent after the Big Bang. In the early stages of the universe, it was filled with a hot, dense plasma that prevented light from traveling freely. However, as the universe expanded and cooled down, about 375,000 years after the Big Bang, the plasma recombined into neutral atoms, allowing light to travel unimpeded. This event is known as recombination and is related to the large-scale structure and evolution of the universe.
Escaping a Yellow Dwarf: The 170,000 years you mentioned is likely referring to the timescale for energy to travel from the core of a yellow dwarf star (like our Sun) to its surface. Inside a star, including a yellow dwarf, energy is generated through nuclear fusion in the core. This energy then slowly diffuses outward through various mechanisms, eventually reaching the star's surface and being emitted as light. The exact timescale for this process depends on the specific conditions inside the star, such as its mass, composition, and internal structure.
These two timescales are entirely different in nature and cannot be directly compared. The transparency of the universe is related to the expansion and cooling of the universe as a whole, while the timescale for energy to escape a star is specific to the processes happening within that star.