  Context: White-light continuum observations of solar flares often have
coronal counterparts, including the classical ``white-light prominence'' (WLP)
phenomenon. Aims: Coronal emissions by flares, seen in white-light continuum,
have only rarely been reported previously. We seek to use modern data to
understand the morphology of WLP events. Methods: We have identified a set of
14 examples of WLP detected by the HMI (Heliospheric and Magnetic Imager)
experiment on board SDO (the Solar Dynamics Observatory satellite), using a new
on-line catalogue covering 2011-2017. These invariably accompanied white-light
flares (WLF) emission from the lower atmosphere by flares near the limb, as
identified by hard X-ray images from RHESSI (the Reuven Ramaty High Energy
Spectroscopic Imager). HMI provides full Stokes information, and we have used
the linear polarisations (Q~and~U) to distinguish Thomson scattering from cool
material. Results: The event morphologies fit roughly into three categories:
Ejection, Loop, and Spike, but many events show multiple phenomena.
Conclusions: The coronal white-light continuum, observed by HMI analogously to
the observations made by a coronagraph, detects many examples of coronal
emission and dynamics. Using the Stokes linear polarisation, we estimate the
masses of hot coronal plasma in 11 of the 14 events and find them to be similar
to typical CME masses, but not exceeding 10$^{15}$\,g. We note that the HMI
observations do not occult the bright solar disk and were not designed for
coronal observations, resulting in relatively low signal-to-noise ratios. We
therefore believe that future such observations with better optimisation will
be even more fruitful.
