A new phenomenon: Astronomers spot two neutron stars being swallowed by different black holes

One of the best things about being an astronomer is being able to discover something new about the universe. In fact, maybe the only thing better is discovering it twice. And that is exactly what my colleagues and I have done, by making two separate observations, just ten days apart, of an entirely new type of astronomical phenomenon: a neutron star circling a black hole before being gobbled up.

The two observations were made in January 2020, by the Laser Interferometer Gravitational-wave Observatory and the Virgo Observatory, both of which detect gravitational waves from the distant cosmos.

After 18 months of painstaking analysis, our discoveries are published in The Astrophysics Journal Letters. The new observations open up new avenues to study the life cycle of stars, the nature of space-time and the behaviour of matter at extreme pressures and densities.

The first observation of a neutron star-black hole system was made on January 5, 2020. Laser Interferometer Gravitational-wave Observatory and Virgo observed gravitational waves – distortions in the very fabric of space-time – produced by the final 30 seconds of the dying orbit of the neutron star and black hole, followed by their inevitable collision. The discovery is named GW200105.

Remarkably, just ten days later, Laser Interferometer Gravitational-wave Observatory and Virgo detected gravitational waves from…

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