Either interpretation, though generally supported by supernova experts, has yet to achieve a totally satisfactory calculation of r -process abundances because the overall problem is numerically formidable. However, existing results are supportive; in 2017, new data about the r -process was discovered when the LIGO and Virgo gravitational-wave observatories discovered a merger of two neutron stars ejecting r -process matter. See Astrophysical sites below.