There are at least 6 bands with this name:

1/ Sedna is an italian post-black metal/sludge band

Bandcamp

2/ Sedna is a brazilian psychedelic trance experimental project.

3/ Sedna a Spanish band focused on celtic music (mainly influenced by Irish music).

4/ Sedna is a Turkish rapper

5/ Sedna is a local death metal band from New Jersey

6/ Sedna is a French pop rock band inspired by britpop/rock bands, now known as Deserty. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.