An Etymological Dictionary of Astronomy and Astrophysics

A nuclear reaction that takes place at high densities and relatively low temperatures. Pycnonuclear reactions are almost temperature independent and occur even at zero temperature. These reactions are extremely slow at densities typical for normal stars but intensify with increasing density. For example, carbon burns into heavier elements at densities over 10¹⁰ g cm^-3.

Etymology (EN): Pycnonuclear, from pycno- a combining form meaning “dense, thick,” from Gk. pyknos “dense, solid” + → nuclear;
→ reaction.

Etymology (PE): Vâžireš, → reaction; cagâl-hasteyi, from cagâl, → dense, + hasteyi, → nuclear.