What is this type of anomaly?
Moving anomaly with defined center structure
BeN, It is a lens-flare artifact. Moisture drop or something refracting/reflecting light in roughly circular pattern onto other parts of the lens systems of the telescope. Some of these may have spikes at the cardinal points, and note the gaps at the 45 degree from cardinal points here. Since the cause is part of the telescope/lens system, you see the same motion of the center as any other flat-field defect. If the center is not visible off-image, it appears to be like a series of moving waves. Star-bleed type artifacts will be centered on a star, and will not 'move' in relation to the background of stars.