Of course, it’s Backyard Worlds: Planet 9. Very early on in the project, I was amazed by the willingness of the lead scientists of Backyard Worlds to engage with all of us amateurs. It was something I hadn’t encountered before, and it makes all the difference in making us feel included. They also have allowed us to use what we’ve learned, and to grow beyond the original scope of the project by letting us do our own side projects and submit our results directly to them, the same as if they came from the main Backyard Worlds site. It’s very satisfying to develop your own project and to have it work out well and, in the process, possibly add a few interesting candidates to the list of astronomical objects to follow up on.