The call sign of the stormtroopers guarding the Millennium Falcon is THX-1138 (referencing Lucas' directorial debut), as opposed to TK-421 in the film. Grand Moff Tarkin is present during Princess Leia's torture. The destruction of Alderaan is not described in the book, nor does Obi-Wan sense it.
The stormtroopers guarding the Millennium Falcon employ the call sign THX-1138 (a reference to Lucas' directorial debut), while TK-421 was used in the film. Grand Moff Tarkin is present during Princess Leia's torture scene. The destruction of Alderaan is not mentioned in the book, nor does Obi-Wan detect it.