An object about 25 times the mass of Jupiter is being drained, a sliver at a time, by a star roughly 85 times Jupiter’s mass, and the two circle each other in just 87 minutes. The pair sits about 300 light-years away and carries the designation ZTF J0440+2325.
The feeding is so gentle that it could continue for hundreds of thousands of years and perhaps for billions. Astronomers at MIT and partner institutions say it is the first time a low-mass star has been caught steadily drawing material from another low-mass object, and they reported the result in the journal Nature Astronomy on October 5, 2026.
An 87-minute orbit that would fit inside the Sun
According to MIT News, the brown dwarf completes an orbit about every 87 minutes. A brown dwarf is an object heavier than a typical planet but too light to sustain the hydrogen fusion that powers ordinary stars, and this one is about 25 Jupiter masses. Its host is a red dwarf of about 85 Jupiter masses.
The orbit is tiny. The ScienceDaily repost of the MIT release says the whole arrangement would fit within the diameter of the Sun. Reporting in Space.com gives the same picture and adds that, unlike the disks that swirl around black holes, this star has no accretion disk to speak of, so the stolen matter lands directly on its surface.
A triangular light curve that did not fit
The discovery began with a pattern in the sky survey data. The Zwicky Transient Facility, a camera on a telescope at Palomar Observatory in California, repeatedly images the sky to catch objects that brighten and fade. Kevin Burdge, an assistant professor of physics at MIT, noticed a signal that rose and fell in a repeating triangular shape rather than the rounded bell of a typical supernova. Burdge said his first reaction on seeing it was that stars do not make triangular waveforms like this, and the signal stayed unexplained for several years.
The team first suspected a black widow binary, in which a neutron star strips material from a small companion. That idea failed on one measurement. Black widow systems show a large back-and-forth wobble, because the companion is so light next to the neutron star, and this system wobbled far less. Follow-up with several telescopes pointed to two low-mass bodies instead, a conclusion Aaron Householder, an MIT graduate student who co-led the work, called “the real clincher for this system.”
The triangle, in the researchers’ account, is the signature of a hot spot. A stream of material pours from the brown dwarf onto the star, and as the two orbit, the glowing impact site swings in and out of view, brightening the system when it faces Earth. Burdge compared the impact to “an asteroid hitting the Moon,” with matter pummeling the surface at very high speed. Computer simulations of test particles leaving the brown dwarf, according to MIT, showed they fall onto the star’s surface rather than forming a disk.
How little is actually being eaten
The rate is modest. The transfer works out to about one hundred-thousandth of an Earth mass each year, according to the MIT release, a trickle set against a companion of 25 Jupiter masses. At that pace the brown dwarf is not about to vanish. As Nautilus relays from the study, the brown dwarf may take billions of years to disappear. Burdge put it this way: “Instead of swallowing the thing up, the star can gradually eat it, for billions of years.”
The duration deserves care. The MIT release says the meal could last hundreds of thousands to billions of years, a wide range with no single figure attached. The release also offered whimsical comparisons for the mass flow, such as truckloads of dirt and pounds of burritos, but pages that checked the arithmetic found those figures inconsistent with the stated rate, and Space.com’s own burger tally differs between its lead and body. The rate in Earth masses is the number to trust.
A first, and more systems to find
Stars swallowing planets is not new. A star can engulf a close companion as it swells, as the Sun is expected to do to Earth, and neutron stars strip companions in black widow systems. What had not been observed, in Householder’s words, was a low-mass star “actively accreting from another low-mass object.” The peer-reviewed paper, published in Nature Astronomy, describes stable mass transfer from a substellar object onto an M dwarf.
A second case turned up in the same study. The arXiv version of the paper reports a companion system, ZTF J1444+4820, with a 67-minute orbit, where a brown dwarf also transfers mass onto an M dwarf. The authors suggest some substellar objects may be consumed gradually over potentially billions of years rather than destroyed quickly.
The team says it is now hunting for relatives. MIT News reports that Householder floated pairings such as a star consuming a planet, or two planets feeding on each other, and said the discovery is “inspiring a lot of new searches” by the group, whose work was supported in part by the National Science Foundation. Whether ZTF J0440+2325 and its 67-minute cousin are rarities or the first of many is what those searches are meant to settle.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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