SPACE/COSMOS
The evolution of life may have its origins in outer space
Astronomers find signs of complex organic molecules – precursors to sugars and amino acids – in a planet-forming disc.
image:
This artist’s impression shows the planet-forming disc around the star V883 Orionis. In the outermost part of the disc, volatile gases are frozen out as ice, which contains complex organic molecules. An outburst of energy from the star heats the inner disc to a temperature that evaporates the ice and releases the complex molecules, enabling astronomers to detect it.
The inset image shows the chemical structure of complex organic molecules detected and presumed in the protoplanetary disc (from left to right): propionitrile (ethyl cyanide), glycolonitrile, alanine, glycine, ethylene glycol, and acetonitrile (methyl cyanide).
view moreCredit: ESO/L. Calçada/T. Müller (MPIA/HdA)
Using the Atacama Large Millimeter/submillimeter Array (ALMA), a team of astronomers led by Abubakar Fadul from the Max Planck Institute for Astronomy (MPIA) has discovered complex organic molecules – including the first tentative detection of ethylene glycol and glycolonitrile – in the protoplanetary disc of the outbursting protostar V883 Orionis. These compounds are considered precursors to the building blocks of life. Comparing different cosmic environments reveals that the abundance and complexity of such molecules increase from star-forming regions to fully evolved planetary systems. This suggests that the seeds of life are assembled in space and are widespread. The findings were published in the Astrophysical Journal Letters today.
Astronomers have discovered complex organic molecules (COMs) in various locations associated with planet and star formation before. COMs are molecules with more than five atoms, at least one of which is carbon. Many of them are considered building blocks of life, such as amino acids and nucleic acids or their precursors. The discovery of 17 COMs in the protoplanetary disc of V883 Orionis, including ethylene glycol and glycolonitrile, provides a long-sought puzzle piece in the evolution of such molecules between the stages preceding and following the formation of stars and their planet-forming discs. Glycolonitrile is a precursor of the amino acids glycine and alanine, as well as the nucleobase adenine.
The assembly of prebiotic molecules begins in interstellar space
“Our finding points to a straight line of chemical enrichment and increasing complexity between interstellar clouds and fully evolved planetary systems.” – Abubakar Fadul, MPIA
The transition from a cold protostar to a young star surrounded by a disc of dust and gas is accompanied by a violent phase of shocked gas, intense radiation and rapid gas ejection.
Such energetic processes might destroy most of the complex chemistry assembled during the previous stages. Therefore, scientists had laid out a so-called ‘reset’ scenario, in which most of the chemical compounds required to evolve into life would have to be reproduced in circumstellar discs while forming comets, asteroids, and planets.
“Now it appears the opposite is true,” MPIA scientist and co-author Kamber Schwarz points out. “Our results suggest that protoplanetary discs inherit complex molecules from earlier stages, and the formation of complex molecules can continue during the protoplanetary disc stage.” Indeed, the period between the energetic protostellar phase and the establishment of a protoplanetary disk would, on its own, be too short for COMs to form in detectable amounts.
As a result, the conditions that predefine biological processes may be widespread rather than being restricted to individual planetary systems.
Astronomers have found the simplest organic molecules, such as methanol, in dense regions of dust and gas that predate the formation of stars. Under favourable conditions, they may even contain complex compounds comprising ethylene glycol, one of the species now discovered in V883 Orionis. “We recently found ethylene glycol could form by UV irradiation of ethanolamine, a molecule that was recently discovered in space,” adds Tushar Suhasaria, a co-author and the head of MPIA’s Origins of Life Lab. “This finding supports the idea that ethylene glycol could form in those environments but also in later stages of molecular evolution, where UV irradiation is dominant.”
More evolved agents crucial to biology, such as amino acids, sugars, and nucleobases that make up DNA and RNA, are present in asteroids, meteorites, and comets within the Solar System.
Buried in ice – resurfaced by stars
The chemical reactions that synthesize those COMs occur under cold conditions, preferably on icy dust grains that later coagulate to form larger objects. Hidden in those mixtures of rock, dust, and ice, they usually remain undetected. Accessing those molecules is only possible either by digging for them with space probes or by external heating, which evaporates the ice.
In the Solar System, the Sun heats comets, resulting in impressive tails of gas and dust, or comas, essentially gaseous envelopes that surround the cometary nuclei. This way, spectroscopy – the rainbow-like dissection of light – may pick up the emissions of freed molecules. Those spectral fingerprints help astronomers to identify the molecules previously buried in ice.
A similar heating process is occurring in the V883 Orionis system. The central star is still growing by accumulating gas from the surrounding disc until it eventually ignites the fusion fire in its core. During those growth periods, the infalling gas heats up and produces intense outbursts of radiation. “These outbursts are strong enough to heat the surrounding disc as far as otherwise icy environments, releasing the chemicals we have detected,” explains Fadul.
“Complex molecules, including ethylene glycol and glycolonitrile, radiate at radio frequencies. ALMA is perfectly suited to detect those signals,” says Schwarz. The MPIA astronomers were awarded access to this radio interferometer through the European Southern Observatory (ESO), which operates it in the Chilean Atacama Desert at an altitude of 5,000 metres. ALMA enabled the astronomers to pinpoint the V883 Orionis system and search for faint spectral signatures, which ultimately led to the detections.
Further challenges ahead
“While this result is exciting, we still haven't disentangled all the signatures we found in our spectra,” says Schwarz. “Higher resolution data will confirm the detections of ethylene glycol and glycolonitril and maybe even reveal more complex chemicals we simply haven't identified yet.”
“Perhaps we also need to look at other regions of the electromagnetic spectrum to find even more evolved molecules,” Fadul points out. “Who knows what else we might discover?”
Additional information
The MPIA team involved in this study comprised Abubakar Fadul, Kamber Schwarz, and Tushar Suhasaria.
Other researchers were Jenny K. Calahan (Center for Astrophysics — Harvard & Smithsonian, Cambridge, USA), Jane Huang (Department of Astronomy, Columbia University, New York, USA), and Merel L. R. van ’t Hoff (Department of Physics and Astronomy, Purdue University, West Lafayette, USA).
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning, and operation of ALMA.
Journal
The Astrophysical Journal Letters
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
A deep search for Ethylene Glycol and Glycolonitrile in V883 Ori Protoplanetary Disk
Article Publication Date
24-Jul-2025
LA REVUE GAUCHE - Left Comment: Search results for PANSPERMIA
LA REVUE GAUCHE - Left Comment: Search results for FRED HOYLE
Astronomers discover star-shredding black holes hiding in dusty galaxies
Unlike active galaxies that constantly pull in surrounding material, these black holes lie dormant, waking briefly to feast on a passing star.
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Astronomers at MIT, Columbia University, and elsewhere have used NASA’s James Webb Space Telescope to peer through the dust of nearby galaxies and into the aftermath of a black hole’s stellar feast.
view moreCredit: NRAO/AUI/NSF/NASA
Astronomers at MIT, Columbia University, and elsewhere have used NASA’s James Webb Space Telescope (JWST) to peer through the dust of nearby galaxies and into the aftermath of a black hole’s stellar feast.
In a study appearing today in Astrophysical Journal Letters, the researchers report that for the first time, JWST has observed several tidal disruption events — instances when a galaxy’s central black hole draws in a nearby star and whips up tidal forces that tear the star to shreds, giving off an enormous burst of energy in the process.
Scientists have observed about 100 tidal disruption events (TDEs) since the 1990s, mostly as X-ray or optical light that flashes across relatively dust-free galaxies. But as MIT researchers recently reported, there may be many more star-shredding events in the universe that are “hiding” in dustier, gas-veiled galaxies.
In their previous work, the team found that most of the X-ray and optical light that a TDE gives off can be obscured by a galaxy’s dust, and therefore can go unseen by traditional X-ray and optical telescopes. But that same burst of light can heat up the surrounding dust and generate a new signal, in the form of infrared light.
Now, the same researchers have used JWST — the world’s most powerful infrared detector — to study signals from four dusty galaxies where they suspect tidal disruption events have occurred. Within the dust, JWST detected clear fingerprints of black hole accretion, a process by which material, such as stellar debris, circles and eventually falls into a black hole. The telescope also detected patterns that are strikingly different from the dust that surrounds active galaxies, where the central black hole is constantly pulling in surrounding material.
Together, the observations confirm that a tidal disruption event did indeed occur in each of the four galaxies. What’s more, the researchers conclude that the four events were products of not active black holes but rather dormant ones, which experienced little to no activity until a star happened to pass by.
The new results highlight JWST’s potential to study in detail otherwise hidden tidal disruption events. They are also helping scientists to reveal key differences in the environments around active versus dormant black holes.
“These are the first JWST observations of tidal disruption events, and they look nothing like what we’ve ever seen before,” says lead author Megan Masterson, a graduate student in MIT’s Kavli Institute for Astrophysics and Space Research. “We’ve learned these are indeed powered by black hole accretion, and they don’t look like environments around normal active black holes. The fact that we’re now able to study what that dormant black hole environment actually looks like is an exciting aspect.”
The study’s MIT authors include Christos Panagiotou, Erin Kara, Anna-Christina Eilers, along with Kishalay De of Columbia University and collaborators from multiple other institutions.
Seeing the light
The new study expands on the team’s previous work using another infrared detector — NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission. Using an algorithm developed by co-author Kishalay De of Columbia University, the team searched through a decade’s worth of data from the telescope, looking for infrared “transients,” or short peaks of infrared activity from otherwise quiet galaxies that could be signals of a black hole briefly waking up and feasting on a passing star. That search unearthed about a dozen signals that the group determined were likely produced by a tidal disruption event.
“With that study, we found these 12 sources that look just like TDEs,” Masterson says. “We made a lot of arguments about how the signals were very energetic, and the galaxies didn’t look like they were active before, so the signals must have been from a sudden TDE. But except for these little pieces, there was no direct evidence.”
With the much more sensitive capabilities of JWST, the researchers hoped to discern key “spectral lines,” or infrared light at specific wavelengths, that would be clear fingerprints of conditions associated with a tidal disruption event.
“With NEOWISE, it’s as if our eyes could only see red light or blue light, whereas with JWST, we’re seeing the full rainbow,” Masterson says.
A Bonafide signal
In their new work, the group looked specifically for a peak in infrared, that could only be produced by black hole accretion — a process by which material is drawn toward a black hole in a circulating disk of gas. This disk produces an enormous amount of radiation that is so intense that it can kick out electrons from individual atoms. In particular, such accretion processes can blast several electrons out from atoms of neon, and the resulting ion can transition, releasing infrared radiation at a very specific wavelength that JWST can detect.
“There’s nothing else in the universe that can excite this gas to these energies, except for black hole accretion,” Masterson says.
The researchers searched for this smoking-gun signal in four of the 12 TDE candidates they previously identified. The four signals include: the closest tidal disruption event detected to date, located in a galaxy some 130 million light years away; a TDE that also exhibits a burst of X-ray light; a signal that may have been produced by gas circulating at incredibly high speeds around a central black hole; and a signal that also included an optical flash, which scientists had previously suspected to be a supernova, or the collapse of a dying star, rather than tidal disruption event.
“These four signals were as close as we could get to a sure thing,” Masterson says. “But the JWST data helped us say definitively these are bonafide TDEs.”
When the team pointed JWST toward the galaxies of each of the four signals, in a program designed by De, they observed that the telltale spectral lines showed up in all four sources. These measurements confirmed that black hole accretion occurred in all four galaxies. But the question remained: Was this accretion a temporary feature, triggered by a tidal disruption and a black hole that briefly woke up to feast on a passing star? Or was this accretion a more permanent trait of “active” black holes that are always on? In the case of the latter, it would be less likely that a tidal disruption event had occurred.
To differentiate between the two possibilities, the team used the JWST data to detect another wavelength of infrared light, which indicates the presence of silicates, or dust in the galaxy. They then mapped this dust in each of the four galaxies and compared the patterns to those of active galaxies, which are known to harbor clumpy, donut-shaped dust clouds around the central black hole. Masterson observed that all four sources showed very different patterns compared to typical active galaxies, suggesting that the black hole at the center of each of the galaxies is not normally active, but dormant. If an accretion disk formed around such a black hole, the researchers conclude that it must have been a result of a tidal disruption event.
“Together, these observations say the only thing these flares could be are TDEs,” Masterson says.
She and her collaborators plan to uncover many more previously hidden tidal disruption events, with NEOWISE, JWST, and other infrared telescopes. With enough detections, they say TDEs can serve as effective probes of black hole properties. For instance, how much of a star is shredded, and how fast its debris is accreted and consumed, can reveal fundamental properties of a black hole, such as how massive it is and how fast it spins.
“The actual process of a black hole gobbling down all that stellar material takes a long time,” Masterson says. “It’s not an instantaneous process. And hopefully we can start to probe how long that process takes and what that environment looks like. No one knows because we just started discovering and studying these events.”
This research was supported, in part, by NASA.
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Written by Jennifer Chu, MIT News
Paper: “JWST’s First View of Tidal Disruption Events: Compact, Accretion-Driven Emission Lines & Strong Silicate Emission in an Infrared-selected Sample”
https://iopscience.iop.org/article/10.3847/2041-8213/ade153
Journal
The Astrophysical Journal Letters
Article Title
“JWST’s First View of Tidal Disruption Events: Compact, Accretion-Driven Emission Lines & Strong Silicate Emission in an Infrared-selected Sample”
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