It appears that N60XC arrived into the Queensland capital from overseas early on Tuesday 21 May.
At the time of writing, N60XC remains parked at Emerald Airport.
UPDATE! It didn't stay for long! After dark on Thursday 23 May, N60XC departed Emerald Airport for Sydney.
Meanwhile, also on Wednesday 22 May, the also familiar sight of Mackellar Mining Equipment / Flight Options (Australia) Cessna 560 Citation Ultra bizjet VH-MMC was also back in CQ. It was noted arriving into Biloela / Thangool Airport once again from the Sunshine Coast.
It too appears to be staying for the night.
UPDATE! Also on Thursday 23 May, VH-MMC departed Bilo and returned to the Sunny Coast.
Finally, on Wednesday 22 May, the Queensland Government Airwing (State of Queensland) Raytheon Hawker 850XP bizjet VH-SGY was back in CQ for the second day in-a-row. On this occasion, it was noted arriving into Mackay Airport from Brisbane. It later departed to Townsville.
And as mentioned below, after arriving the previous day, also on Wednesday 22 May, the Queensland Police Service (Airwing) (State of Queensland) Cessna 560 Citation Ultra bizjet VH-PSU departed Longreach Airport and completed a local flight before departing a little later on and heading to Brisbane.