Using the Gran Telescopio Canarias (GTC) and the Apache Point Observatory (APO), an international team of astronomers has detected 19 pulsation modes in an ultra-massive white dwarf known as WD J0135+5722. The discovery, presented on the arXiv preprint server, makes WD J0135+5722 the richest pulsating ultra-massive white dwarf known to date. Using the Gran Telescopio Canarias (GTC) and the Apache Point Observatory (APO), an international team of astronomers has detected 19 pulsation modes in an ultra-massive white dwarf known as WD J0135+5722. The discovery, presented on the arXiv preprint server, makes WD J0135+5722 the richest pulsating ultra-massive white dwarf known to date. Astronomy Phys.org – latest science and technology news stories