Aside: what are the icons beside people's names? Particularly the pentagram star one... Assuming something to do with the Fediverse, but not Mastodon? Yet seein

Aside: what are the icons beside people's names? Particularly the pentagram star one... Assuming something to do with the Fediverse, but not Mastodon? Yet seeing number of entries link to a Mastodon instance, but also some other sites like some kind of ActivityPub server etc... Wasn't the Fediverse logo supposed to be that three-asterisk thing?