Upon reaching a density of approximately 400 billion grams per cubic centimeter, white dwarfs may begin to turn into them.
Holes in these objects are known as anti-meatball, anti-spaghetti, or anti-lasagna, depending on density, and the upper bound to their mass is given by the Tolman-Oppenheimer-Volkov limit. Upon reaching a density of approximately 400 billion grams per cubic centimeter, white dwarfs may begin to turn into them. First discovered in standalone form by Jocelyn Bell, for 10 points, name these extremely dense stars often formed as a result of supernovae, which contain lots of the namesake neutrally- charged subatomic particle.
Holes in these objects are known as anti-meatball, anti-spaghetti, or anti-lasagna, depending on density, and the upper bound to their mass is given by the Tolman-Oppenheimer-Volkov limit.
{neutron} stars