What was found
ON APPROACH, PF CALLED FOR GEAR DOWN BEFORE LANDING CHECK AND AFTER GEAR PLACED IN DOWN POSITION, THE RIGHT HALF LANDING GEAR LIGHT DID NOT ILLUMINATE. PM CALLED FOR CHECKLIST, CONSULTED MAINTENANCE AND OPS. APPROACH WAS BROKEN OFF AND DELAY VECTORS REQUESTED WHILE GOING THROUGH CHECKLIST. AFTER ALL CHECKLIST COMPLETED, DECLARED EMERGENCY. LANDING UNEVENTFUL. MAINTENANCE REPLACED THE BULB IN THE INDICATOR, AND OPS CHECKED SATISFACTORY.