Some stars have planets. Others are orbited by brown dwarfs, balls of gas too massive to be planets, but too low-mass to be stars. Astronomers love these brown dwarf-star pairs because being paired with a star helps reveal a brown dwarf’s age.
Source: [NASA](https://science.nasa.gov/get-involved/citizen-science/search-for-hidden-cosmic-companions-in-suns-backyard/)