Langer, N. Max Planck Institute for Radio Astronomy, Max Planck Society;
Gvaramadze, V., Gräfener, G., Langer, N., Maryeva, O., Kniazev, A., Moskvitin, A., et al. (2019). A massive white-dwarf merger product before final collapse. nat, 569(7758), 684-687. doi:10.1038/s41586-019-1216-1.