Fumarole is a period5 oscillator that was found by Dean Hickerson on September 3, 1989.^{[1]} In terms of its 18 cells it is the fourth smallest period 5 oscillator, after pseudobarberpole, octagon 2, and Silver's p5; however, its 7 × 8 bounding box is the smallest of any known period 5 oscillator.
The domino spark that it provides makes it useful in the construction of higher period oscillators such as the p35 beehive hassler, p40 Bheptomino shuttle, and 98P25. On September 1, 1995, Noam Elkies found a way to nontrivially combine two fumaroles and a blinker into a period10 oscillator, shown below;^{[2]} 4 can be combined in a similar fashion.
x = 15, y = 12, rule = b3/s23
2o13b$o2b2o4bo5b$b2ob2o3bo5b$4b2o3bo5b$4b2o9b$b2ob2o4b2o3b$o2b2o3bo4bo
b$2o6bo4bob$8bo4bob$9bo2bo2b$7bobo2bobo$7b2o4b2o!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ THUMBNAIL THUMBSIZE 2 ZOOM 16 ]]

2 fumaroles and a blinker (click above to open LifeViewer) RLE: here Plaintext: here 
Construction
In February 2000, Stephen Silver found a 7glider synthesis of this oscillator.^{[3]} There are known alternate syntheses.^{[4]}^{[5]} In 2024, Carson Cheng found a 6glider synthesis.^{[6]}
Occurrence
 See also: List of common oscillators
On Catagolue, it is the second most common period 5 oscillator, being less common than octagon II but more common than Elkies' p5.^{[7]}
x = 9, y = 11, rule = B3/S23
o5bo$o2b2o$2bo2bo$3bobo$4bo5$b2o4b2o$b2o4b2o!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ THUMBNAIL THUMBSIZE 2 ZOOM 16 ]]
 A very common predecessor of fumarole involves two blocks and a region resembling two xWSS heads welded together.^{[8]} (click above to open LifeViewer) RLE: here Plaintext: here 

x = 18, y = 7, rule = B3/S23
8b2o$7bo2bo$7bo2bo$3o5b2o5b3o$o2bo10bo2bo$o2bo10bo2bo$b3o10b3o!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ THUMBNAIL THUMBSIZE 2 ZOOM 16 ]]
 A stator variant of fumarole can form from a pond and two fleet predecessors.^{[9]} (click above to open LifeViewer) 

See also
References
External links