> Instead, it circles a brown dwarf, an object larger than a planet, that orbits the CD-35 2722 star.

Isn't the dividing line between the largest possible gas giants and the smallest brown dwarfs a bit fuzzy?

https://en.wikipedia.org/wiki/Substellar_object

The definition of a brown dwarf is that there is enough heat and compression for deuterium and/or lithium fusion, but not protium fusion.

The exact model limit is unclear, but the physics modelling is relatively straightforward.