SN 1987A: neutrinos from a collapsing core reach Earth
Three underground detectors - Kamiokande-II in Japan, IMB in Ohio and Baksan in the Soviet Union - recorded a coincident burst of neutrino interactions lasting about a dozen seconds, totalling roughly two dozen events. The optical supernova was found in the Large Magellanic Cloud, about 50 kiloparsecs away, the following night. It remains the only occasion on which the collapse of a stellar core has been observed by any means other than the light it eventually produced, and the neutrino timing and energies matched core-collapse predictions closely enough to confirm the mechanism. The progenitor, catalogued as Sanduleak -69 202, was a blue supergiant rather than the red supergiant theory expected - a genuine surprise that forced revisions to massive-star evolution models. Event counts are quoted inconsistently in the literature, with Kamiokande-II's given as both 11 and 12.
Observed — measured or witnessed, with the observation cited.
Subjects
- Supernova · phenomenon · not located
- Neutron star · celestial body · Galactic · not located
- Kamioka Observatory, Mozumi mine · research facility · Japan
- Initial stellar mass · physical quantity · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Detection of the SN 1987A neutrino burst at Kamiokande-II, IMB and Baksan
Records a coincident neutrino burst at approximately 07:35 UT on 23 February 1987 across three detectors, totalling roughly two dozen events. Volume and page numbers are deliberately not asserted because they were not confirmed. Reported event counts differ between accounts: Kamiokande-II is quoted as both 11 and 12 events, with 8 for IMB and 5 for Baksan.
Physical Review Letters (Kamiokande-II, IMB) and the Baksan Underground Scintillation Telescope group · 1987 · Partly verified
K. Hirata et al. (Kamiokande-II) and R. M. Bionta et al. (IMB), Physical Review Letters (1987); E. N. Alekseev et al., "Detection of a Neutrino Signal from SN 1987A on February 23, 1987 at 7:35 UT: Data from the Baksan Underground Scintillation Telescope"
Recorded on Supernova
- A guest star appears in Taurus and is recorded in East Asia
- Baade and Zwicky propose supernovae and neutron stars
- A regularly pulsing radio source is identified
- A pulsar is found inside the Crab Nebula
- SN 1987A: neutrinos from a collapsing core reach Earth
- A neutron-star merger is detected in gravitational waves and light
- A radius is measured for the heaviest known neutron star
- JWST finds the compact object in SN 1987A
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- JWST finds the compact object in SN 1987A · 2024-02-22
- A radius is measured for the heaviest known neutron star · 2021
- A neutron-star merger is detected in gravitational waves and light · 2017-08-17
- A pulsar is found inside the Crab Nebula · 1968
- A regularly pulsing radio source is identified · 1967-11-28
- Baade and Zwicky propose supernovae and neutron stars · 1934
- A guest star appears in Taurus and is recorded in East Asia · 1054 (first sighting commonly given as 4 July; contested)