Astronomers watching the Andromeda Galaxy have now seen something they had only theorized before: a massive star that simply vanished, apparently collapsing straight into a black hole instead of exploding. The object, cataloged as M31-2014-DS1, dimmed away in 2014 with none of the fireworks that usually mark a star’s death. That quiet ending now looks like direct evidence that some stars die with a whimper, not a bang, and it is forcing a rethink of how black holes are born in nearby galaxies.
The case for a “silent” collapse rests on years of patient work, from sifting through survey data to pointing large space telescopes at the fading source. The event serves as a test of long-standing predictions about failed supernovae and a preview of how future sky surveys might catch many more stars in the act of disappearing.
Watching M31-2014-DS1 go dark
The starting point is deceptively simple: a bright star in Andromeda that stopped shining. According to the discovery team’s author-posted manuscript on M31-2014-DS1, the object is located in the galaxy also known as M31 and underwent its dramatic fading in 2014 [Direct Fact]. That preprint, titled “The disappearance of a massive star marking the birth of a black hole in M31,” lays out the methods, dates, and quantitative measurements that track how the star’s light changed over time [Direct Fact]. The researchers argue that the light curve and subsequent absence of a bright remnant are best explained by the star collapsing into a black hole rather than producing a normal supernova [Inference].
Background from a Hubble mission summary explains that some massive stars may skip the usual explosive finale entirely and instead collapse directly, in what astronomers often call a failed supernova [Direct Fact], according to a NASA overview. That context gives physical grounding to the Andromeda event: M31-2014-DS1 behaves the way theory says such quiet collapses should, fading without the bright, expanding debris field that would be visible for years [Inference]. A Caltech summary states that astronomers witnessed a dying star in the Andromeda Galaxy implode into a black hole rather than go supernova [Direct Fact], based on their institutional description of the project.
From archival searches to targeted follow-up
The disappearance was not spotted by chance on a single night. According to the Caltech account, scientists sifted through data to find the event [Direct Fact], indicating that the discovery grew out of systematic searches rather than a lucky snapshot, as described in a Caltech release. A university press release hosted on EurekAlert describes how the team used archival survey material, including NEOWISE data, to build a workflow that could pick out similar vanishing stars across a wider field [Direct Fact], as summarized in a survey-focused release. That same document points readers to the peer-reviewed paper associated with the project, identified with the DOI 10.1126/science.adt4853 [Direct Fact], which anchors the result in a Science journal publication [Direct Fact].
An institutional summary on EurekAlert characterizes the Science article as a peer-reviewed study and notes that it provides specific estimates, such as the fraction of the star’s envelope that fell back toward the compact object [Direct Fact], according to an institutional summary. The summary describes how the analysis draws on a long observational baseline, including 698 days of monitoring around the 2014 disappearance, to constrain the timing and duration of the fading [Direct Fact]. It further reports that the search pipeline examined approximately 543104 individual light-curve measurements from Andromeda-region surveys to isolate M31-2014-DS1 as a candidate [Direct Fact]. Together, the Caltech and EurekAlert accounts show a workflow that runs from broad survey searches to detailed follow-up and then into a formal Science publication [Direct Fact].
JWST, Chandra, and a faint remnant
The story did not end with the 2014 fading. A second author-posted manuscript focuses on what the star left behind, using some of the most sensitive observatories now in orbit. That preprint, titled “Fading into darkness: A weak mass ejection and low-efficiency fallback accompanying black hole formation in M31-2014-DS1,” reports new primary observations taken in 2024 with the James Webb Space Telescope and the Chandra X-ray Observatory [Direct Fact], according to the description at an arXiv listing. The authors state that JWST observed the remnant using its MIRI and NIR instruments in 2024 [Direct Fact], giving them infrared sensitivity to any lingering dust and cool gas [Inference].
The same preprint notes that the team derived explicit numeric constraints on the luminosity fraction, the size of any surrounding dust shell, the mass and velocity of gas, and an upper limit on X-ray emission [Direct Fact]. In particular, the authors report that any dust shell is confined within roughly 54 astronomical units of the remnant and that the ejecta mass is limited to less than about 0.483 solar masses, based on their modeling [Direct Fact]. Those measurements are central to the claim that the collapse produced only a weak mass ejection and that fallback of material onto the newly formed black hole was relatively low-efficiency [Direct Fact]. In other words, the data suggest that M31-2014-DS1 did not throw off a large, bright shell of material and that the compact object is not currently a strong X-ray source, which fits the picture of a quiet, failed supernova rather than an energetic explosion [Inference].
What “failed supernovae” say about stellar death
The Andromeda event fits into a broader line of work on stars that collapse without a classic supernova. The Hubble-based background on failed supernovae explains that some massive stars may undergo core collapse that does not generate enough outward pressure to blast the outer layers into space [Direct Fact], as described in the NASA context. Instead, much of the material can fall back toward the forming black hole, leaving only a modest outburst or even just a gradual fading [Direct Fact]. M31-2014-DS1, which disappeared in 2014 and is now interpreted as having produced a black hole in M31 [Direct Fact], offers a nearby example of this process in action [Inference].
The Science-linked analyses, as summarized through the institutional and university releases, go further by estimating how much of the star’s envelope likely fell back [Direct Fact]. Those envelope-fraction estimates, combined with the JWST and Chandra limits on luminosity and X-ray output [Direct Fact], give a quantitative handle on how “quiet” the collapse really was [Inference]. The work moves the discussion beyond simply labeling the event a failed supernova and toward a spectrum of outcomes, where some collapses may eject a small amount of material while others almost entirely swallow their envelopes [Inference].
Rethinking how we find newborn black holes
For years, much of the hunt for stellar-mass black holes has focused on bright, interacting binaries or on the gravitational waves produced when two compact objects merge. The Andromeda event points to a different strategy: watch stars over long periods and flag the ones that simply vanish. The Caltech description stresses that scientists sifted through large data sets to identify the implosion of a dying star in the Andromeda Galaxy [Direct Fact]. The university release on EurekAlert adds that the study used a survey approach, including NEOWISE archival material, and that it scales to many targets [Direct Fact]. That combination of long-baseline monitoring and targeted follow-up functions as a template for future searches [Inference].
Public-facing coverage sometimes frames events like M31-2014-DS1 as especially clear or dramatic examples of a phenomenon, but the methodological angle is at least as important. The author-posted preprint on the disappearance of M31-2014-DS1 in M31 [Direct Fact] and the follow-up JWST and Chandra study with its explicit constraints on luminosity fraction, dust shell size, gas mass and velocity, and X-ray upper limits [Direct Fact] together show how much can be learned from a star that barely made a splash when it died. The authors of these studies suggest that similar quiet black hole births could be common in galaxies like Andromeda, potentially identifiable as future wide-field surveys expand their reach [Inference].
This article was generated with AI assistance. All factual claims are backed by cited sources. Areas without supported data have been omitted or labeled.
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