B29
B29  
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Pattern type  Tagalong Spaceship  

Number of cells  29  
Bounding box  10×17  
Direction  Diagonal  
Period  4  
Mod  4  
Speed  c/4  
Heat  30  
Discovered by  Hartmut Holzwart  
Year of discovery  2004  
 
 

B29 is a c/4 diagonal spaceship discovered by Hartmut Holzwart in September 2004.^{[1]} In generation 2 it produces an isolated domino spark that can be used to perturb reactions. In terms of its 29 cells, it is the fourth smallest c/4 diagonal spaceship, as well as the smallest c/4 spaceship to not exhibit glide symmetry. There are three ways in which a glider can nontrivially follow a B29, as shown below.
Due to a synthesis completed by Tanner Jacobi in April 2015, B29 is one of relatively few elementary diagonal spaceships with a known glider synthesis  not counting the Corderships, which include several infinite families of constructible arrangements of switch engines.
Two gliders can be seen at the front of the ship, one of these being temporary and the other permanent, making this a tagalong. The other glider does not stay as a glider but still moves like one.