M31-2014-DS1

M31-2014-DS1 is a failed supernova candidate located in the Andromeda Galaxy (M31). It is a massive star observed to have undergone a "silent" collapse directly into a black hole without a characteristic supernova explosion. The event, characterized by a brief infrared brightening followed by the total disappearance of the progenitor star in optical wavelengths, provides observational evidence for the failed supernova theory of stellar evolution.^[1]

The progenitor star was identified in archival data as a luminous red supergiant with an initial mass estimated at approximately 13 M_☉.^[1] In 2014, the object underwent a significant mid-infrared outburst, increasing in luminosity as detected by the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer (WISE).

Following this peak, the star began a steady decline in brightness. By 2023, deep imaging from the W. M. Keck Observatory and the Hubble Space Telescope confirmed that the star was no longer visible. Unlike a standard Type II supernova, no luminous optical transient was detected during the collapse.^[1]

The disappearance of M31-2014-DS1 is attributed to the collapse of the stellar core after the exhaustion of nuclear fuel. In typical stars of this mass range, the collapse triggers a shockwave that expels the outer layers. However, in the case of M31-2014-DS1, the shock failed to overcome the material falling inward.^[1]

Theoretical models of the collapse suggest a brief, intense burst of neutrinos occurred at the moment of event horizon formation. The abrupt cessation of the neutrino signal marks the exact point of black hole birth.^[2]

The infrared signature observed in 2014-2016 is believed to be caused by a small fraction of the stellar envelope (~1 M_☉) being ejected at low velocities, subsequently cooling and forming a shroud of dust.^[1] The remaining mass collapsed into a stellar-mass black hole.

The discovery addresses the "missing supernova" problem, where the number of observed supernovae is lower than predicted by the star formation rate. M31-2014-DS1 suggests that a significant fraction of massive stars may end their lives as failed supernovae rather than in bright explosions.^[1]

Recent studies have also used this event to calibrate neutrino detectors like Super-Kamiokande, as the energy profile of the neutrinos provides data on the mass of the progenitor and the state of matter during collapse.^[2]

Several researchers have proposed alternative models to explain the star's infrared behavior and subsequent disappearance in optical wavelengths.

Some models suggest the 2014 infrared outburst was not a precursor to the collapse, but rather a luminous red nova event caused by the merger of two stars. In this scenario, the "disappearance" is actually the merged remnant being temporarily shrouded by a thick, expanding shell of ejected material.^[3]

Observations in early 2026 using the James Webb Space Telescope (JWST) have detected a persistent, albeit faint, mid-infrared source at the progenitor's coordinates. This has led some astronomers to argue that the star has not vanished, but as instead entered a phase of extreme mass loss, creating a dust cocoon thick enough to block all visible light.^[4]

A 2026 preprint suggests the event could be an unusually long-duration eruption of a luminous blue variable star, which can mimic the appearance of a "disappearing" star before eventually re-emerging decades later.^[3]

• Gravitational collapse
• N6946-BH1 - another failed supernova candidate
• Stellar evolution