The B dominant sharp ninth chord is a 5-note chord consisting of the notes B, D#, F#, A and C##.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as B7#9.
Chords that are a subset of B7#9. These contain less notes but all of them are included in B7#9.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the B7#9 chord. Feel free to save or share the image as needed.