The 
-sunlet graph is the graph on 
vertices obtained by attaching 
pendant edges to a cycle graph 
(ISGCI), i.e., the coronas 
(Frucht 1979). Sunlet graphs have also been
called crown graphs (e.g., Gallian 2018), a terminology that conflicts with the use
of the term "crown graph" in this work to
refer to a rook complement graph 
. They are also known as "sun graphs,"
which conflicts with the use of that term in this work.
Sunlet graphs are trivially unit-distance graphs, as well as matchstick graphs. They are also graceful (Frucht 1979).
Note that Wallis (2000) and Anitha and Lekshmi (2008) use the term "
-sun" graph to refer to sunlet graphs, whereas ISGCI and
other authors reserve that term for a different type of graph.
The 3-sunlet graph is also known as the net graph.
If the restriction 
in the I graph 
is loosened, the 
-sunlet graph corresponds to 
.
