Fed. R. Evid. 614 — Court’s Calling or Examining a Witness

(a) CALLING. The court may call a witness on its own or at a party’s request. Each party is entitled to cross-examine the witness.

(b) EXAMINING. The court may examine a witness regardless of who calls the witness.

(c) OBJECTIONS. A party may object to the court’s calling or examining a witness either at that time or at the next opportunity when the jury is not present.