Is the Nikon d5000 compatible with the Nikon Flash Sb-900?

I'm photographing a party tomorrow and the person rented a Nikon flash sb-900 for me and i won't get it until i arrive at the party. I'm sort of freaking out because I'm not fully sure if it will work with my Nikon D5000 or if there's something I need to make it work.

Yes

Did you happen to think to look in your user manual to see which flash units are compatible? The user manual of the SB-900 also lists the D5000

Is there a compelling reason you did not check on the Nikon website, look up the SB900 and look for the compatible cameras?

Do that next time and save yourself some time

Don't worry it will work if you put some battery in it.

It will work on-camera, but not remotely (as in off-camera) unless you get a SC-29 cable or setting it up as a slave (and going manual exposure, etc).

But you can probably get by with strictly using it on-camera via the hot-shoe.