What causes as forum topic title to get a star instead of the typical dot?

[Serack he/him]

Similarly, what flags some original posts in a topic with a heart banner at the top right? (like this one)

I've noticed some of my favorite posts have these features, but just now a new topic I made that had only 1 reply and 1 up arrow heart had a Star in front of it's link

Which has me really wondering what mechanic flags these posts this way

[AonEne he/him]

The dot changes to a star when you post in a topic. The heart happens when a post gets 17 reputation (fairly certain it's that, but could be 16). They are separate.  

[Serack he/him]

3 minutes ago, AonEne said:

The dot changes to a star when you post in a topic. The heart happens when a post gets 17 reputation (fairly certain it's that, but could be 16). They are separate.  

So the star means it's a topic you've been posting in.  Thanks

[AonEne he/him]

Happy to help!