# Do some comets spin? If so, how fast?

The GIF below is copied from my question earlier What might a CN filter be in the context of comet watching? Is it showing dust, or gas, or something else? where I'd said:

In this post on the website for the Comet Wirtanen Observing Campaign at wirtanen.astro.umd.edu, there's mention of a CN filter being used to observe the comet, and this cool GIF.

It certainly looks like the comet is spinning; it reminds me of images of the density of the solar wind as active areas on the sun "spray" out matter as the Sun rotates, or the patterns discussed in Why is one of these two concurrent fuel-dump spirals blue?.

Question: This leeds me to wonder if I'm just imagining things, or if some comets really do spin? If so, how fast have they been observed to rotate?

Searching the JPL Small Body Database (select Object Kind=Comets, set Limit by object characteristics using rot_per (h) greater than 0, add rotation period (h) to the Output Fields) should produce a list of 21 comets with measured rotation periods: