Astronomers catch a red dwarf slowly feeding on its brown dwarf companion
MIT-led astronomers say ZTF J0440+2325, 300 light-years away, is the first system seen where one low-mass object steadily feeds on another. Nobody has settled how long the feeding can last, and published estimates run from hundreds of thousands to billions of years.
The Scientist · Science desk
What happened
- The feeding star is a red dwarf and its companion is a brown dwarf, with material appearing to flow from the brown dwarf onto the red dwarf.
- Kevin Burdge of MIT first noticed the system years ago in Zwicky Transient Facility data as a triangular brightness pattern that repeated again and again.
- Burdge and Aaron Householder, an MIT graduate student and the study's lead author, later revisited the source and measured its wobble with multiple telescopes.
- The study appeared in Nature Astronomy alongside a separate paper on a white dwarf that seems to be fed by the atmosphere of a planet orbiting it.
Why it matters
- What it limits constraint With one system on record, the find shows a slow feeding state between two low-mass objects can exist but cannot yet show how often close pairs end up in it.
- What doesn't add up contradiction Anyone repeating the billions-of-years figure is quoting the top of a projection that a second account of the same paper puts at millions.
- What doesn't add up contradiction The idea that the sun may nibble at Earth goes beyond what was measured, and it conflicts with Burdge's own statement that Earth will be swallowed.
Next story · Science · 6d ago
MIT astronomers find a star slowly stripping a brown dwarf 300 light-years awayConfirmed2 publishers
The case for what ZTF J0440+2325 is rests on a process of elimination. Burdge's first guess was a black widow binary, in which a dense, spinning neutron star slowly consumes a much smaller companion [8]. In those systems the light wobbles as the low-mass companion whips around its heavy partner [8]. "We weren't seeing that whipping back and forth here," Burdge said [9].
A missing wobble fits two partners with no heavy anchor between them. "If you have less mass in the system overall, things can gently orbit each other without whipping back and forth," he said [10]. For years that was only a hunch. "That was the idea. But we never had any proof. And this weird triangle just sat for years," Burdge said [11].
I think the elimination argument holds, at least as far as the coverage describes it. Black widows already show slow feeding [8]. The new claim in the MIT account is narrower: one low-mass object feeding on another [1].
The lifetime is less firm. MIT's account says the feeding rate suggests the process could carry on for hundreds of thousands or even billions of years [4]. Scientific American, describing the same study, says millions [5]. Read as 100,000 years against 1 billion, MIT's own range spans a factor of 10,000 [17]. Burdge quoted the top of it: "Instead of swallowing the thing up, the star can gradually eat it, for billions of years," he said [18]. MIT's figures are projected from the current feeding rate [4]. The coverage does not report that rate or the masses of the two objects.
Earth comes up in the same quote. "This is what will happen to the Earth when the sun becomes a red giant," Burdge said, describing the usual picture in which the star swallows its companion [18]. Scientific American applied the finding to the sun anyway. It wrote that Householder's research suggests the sun might one day nibble away at Earth's atmosphere [19]. The sun is a yellow dwarf [15]. The star measured here is a red dwarf [3].
Householder called the discovery "a happy accident" [13]. "We're excited to see if we can find a star eating a planet or maybe even two planets eating each other," he said [14].
What to watch
- The paper's measured masses and mass-transfer rate, which would show whether the lifetime sits nearer hundreds of thousands, millions, or billions of years.
- Further survey detections of repeating triangular light curves, or the star-planet pairs Householder wants to find, which would show whether this feeding state is common.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence62
- Adoption
- Not scored
- Hype gap+15
- Incentives
- Not scored
- Confidence55
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
ZTF J0440+2325 is within the Milky Way, roughly 300 light-years from Earth, and is the first observation of a low-mass object slowly and steadily consuming material from another low-mass object.
- [2]
Scientists at MIT and elsewhere report in Nature Astronomy a star consuming a closely orbiting brown dwarf, an object more massive than a planet but not as big as a star.
- [3]
In the system a red dwarf is slowly and steadily consuming a brown dwarf; material seems to be flowing from the brown dwarf to the red dwarf.
- [4]
The rate at which the star is feeding from the brown dwarf suggests the process could carry on for hundreds of thousands or even billions of years.
- [5]
Material flowing from the brown dwarf to the red dwarf is in a process that could continue for millions of years.
- [6]
The system was first spotted by the Zwicky Transient Facility, which uses a camera on a telescope at Palomar Observatory in California to scan the sky for rapid changes in brightness.
- [7]
Several years ago Kevin Burdge, assistant professor of physics at MIT, noticed in ZTF data a light curve shaped like a triangle that appeared again and again.
- [8]
In a black widow binary an extremely dense, spinning neutron star slowly consumes a much smaller companion star, and the light wobbles as the low-mass object whips around the much heavier one.
- [9]
"We weren't seeing that whipping back and forth here,"
- [10]
"If you have less mass in the system overall, things can gently orbit each other without whipping back and forth,"
- [11]
"That was the idea. But we never had any proof. And this weird triangle just sat for years."
- [12]
Burdge and Aaron Householder, a graduate student in MIT's Department of Earth, Atmospheric and Planetary Sciences, revisited the signal, focused multiple telescopes on the source and measured various properties including its wobble.
- [13]
Aaron Householder, lead author and MIT graduate student, called the discovery "a happy accident."
- [14]
"We're excited to see if we can find a star eating a planet or maybe even two planets eating each other"
- [15]
The sun is a yellow dwarf star; orange and red dwarfs are other types.
- [16]
The study was one of a pair published in Nature Astronomy; the other, led by Jamie Williams of the University of Warwick, describes a white dwarf apparently being fed by the atmosphere of a planet orbiting it.
- [17]
Taking the low end of MIT's lifetime range as 100,000 years and the high end as 1 billion years, the range spans a factor of 10,000.
- [18]
"When we think of stars interacting with planets or brown dwarfs, the picture is always that the star eventually swallows the other thing. This is what will happen to the Earth when the sun becomes a red giant. But here, we've found an alternative: Instead of swallowing the thing up, the star can gradually eat it, for billions of years."
- [19]
Householder's research suggests that rather than make a quick and fiery meal of Earth, the sun might one day nibble away at Earth's atmosphere.
Sources
2 independent publishers whose own reporting we read for this story.
- phys.orgAstronomers catch a star slowly snacking on a brown dwarf, 300 light years away
1 article · October 5, 2026
- scientificamerican.comAstronomers catch dwarf stars gobbling up their orbiting companions | Scientific American
1 article · October 5, 2026
Topics and entities
Topics
- Stellar accretion
- Time-Domain Astronomy
- Brown dwarfs
- Star-planet interactions
Entities
- Nature Astronomy
- Aaron Householder
- MIT
- Zwicky Transient Facility
- University of Warwick
- Palomar Observatory