Irish astronomers, in cluding researchers from Dublin Institute for Advanced Studies (DIAS), are part of an international team that has detected radiation from a veiled neutron star in the Supernova 1987A (SN 1987A), using the James Webb Space Telescope (JWST). The findings from the study were published today (22.02.2024) in the journal Science.

Commenting on the discovery, Tom Ray, Senior Professor and Director of Cosmic Physics at DIAS, said “When a massive star exploded back in 1987, and easily visible to the naked eye, it was the nearest such explosion to Earth in almost four hundred years. Supernovae, as these explosions are called, are thought to leave a collapsed remnant of their star behind but the search for the remnant proved very difficult and only indirect evidence was found. We are, of course, very excited that the Webb has shown us where the remnant is, verifying our understanding of such explosions.”

Using the Mid-Infrared Instrument (MIRI), astronomers were able to observe narrow emission lines from ionized argon and sulphur atoms located at the centre of a nebula around SN 1987A. The team concluded that the emission line strengths observed by the Webb Telescope must be triggered by radiation from the hot neutron star or from a pulsar wind nebula around the neutron star.

Professor Ray along with Dr Patrick Kavanagh, DIAS Research Associate and a faculty member of Maynooth University, and Jeroen Jespers, an Astronomy and Astrophysics PhD student at DIAS and Maynooth, played a significant role in the discovery.

Professor Ray is Co-Principal Investigator on the Mid-Infrared Instrument (MIRI) on the Webb Telescope and has worked on its development for over two decades. Dr Kavanagh has also worked on the MIRI and is a member of the Supernova 1987A team that made the discovery of the long sought collapsed stellar remnant at the centre of the supernova. He is one of the main authors of the study and an SFI-IRC Pathway Fellow.

Commenting today, Dr. Eucharia Meehan, CEO and Registrar of DIAS, said: “This is an exciting day for us at DIAS which sees years of work coming to fruition and another mystery of the universe unveiled. Our scientists involved in the development of the Mid-Infrared Instrument and the SN 1987A team are at the forefront of ground-breaking research in space, helping us to unlock mysteries of the universe. After four centuries, it is finally possible to show conclusive evidence for the presence of a neutron star at the centre of SN 1987A. It is wonderful that Ireland played an important role in this discovery, recently announced by Dr Kavanagh in Denver at the American Association for the Advancement of Science.”

Supernova 1987A (SN 1987A) was the first supernova visible to the naked eye in four centuries and provided astronomers with a close-up view of a supernova explosion using modern observatories. SN 1987A is one of the most studied objects in our skies and the detection of neutrinos, unimaginably small sub-atomic particles produced in the supernova, indicated that a neutron star must have formed. However, whether or not the neutron star persisted or collapsed into a black hole has been one of the biggest puzzles regarding SN 1987A. Even after three and a half decades of intense monitoring with cutting-edge, world-class observatories, no conclusive evidence for the presence of a neutron star at the centre of SN 1987A has been found, until now.