Octagon 2 was the first known period 5 oscillator, discovered in 1971 independently by Sol Goodman and Arthur Taber; the name is due to the latter. Its discovery was first reported in Lifeline Volume 1.
In December 2014, forum user flipper77 discovered that four pre-traffic lights could hassle the octagon, turning it into a period 4 oscillator.
Octagon 2 is about the twenty-sixth most common naturally-occurring oscillator in Achim Flammenkamp's census, being about as common as unix. On Catagolue, it is the most common period 5 oscillator, being more common than fumarole.
- 16P5.1 at Heinrich Koenig's Game of Life Object Catalogs