Expansion of an X-ray coronal arch into the outer corona

An asymmetric, expanding arch, photographed in the inner corona with an X-ray telescope on 13 August, 1973, is identified as the source of the mass ejected in a white light transient in the outer corona. The morphology, angular position, estimated mass and apparent rate of upward acceleration of the lower coronal arch are similar to those of the arch seen passing through the outer corona. The mass of material removed from the lower corona is estimated at 2 x 1015g, and the upward movement is consistent with a constant acceleration of 12.5 ms-2 between 1.3 and 5R(sun). (Auth.)