James Webb Space Telescope: Finally, the edge of the universe and beyond
Launched in 2021 on Christmas Day, the James Webb Space Telescope is the most complex, precise and powerful space observatory ever built.
The telescope's unrivaled resolution and sophistication are due in no small part to the many cutting-edge devices it contains, including a guidance camera and a scientific instrument developed by researchers at Université de Montréal's Institut de recherche sur les exoplanètes (iREx).
Now these same scientists, under the direction of René Doyon, a professor in UdeM's Department of Physics, can see the fruit of their efforts and expertise, as initial data captured by the telescope has been made public.
The first photo taken by James Webb was released by U.S. President Joe Biden on July 11, 2022, and is of unprecedented color and clarity. It is the deepest, sharpest infrared image yet taken of the distant universe: A cluster of galaxies formed over 13 billion years ago.
Four more images were then unveiled live on July 12 from NASA's Goddard Space Flight Center in Greenbelt, Maryland. The images showed the Carina and Southern Ring nebulae in unparalleled sharpness, in addition to Stephan's Quintet, a visual grouping of five galaxies.
James Webb's first-ever spectroscopy of the exoplanet WASP-96 b, located 1,000 light-years from Earth, was also made public. Using this technique to determine the chemical composition of a distant object, the telescope captured the distinct signature of water, as well as evidence of clouds and haze.
Nathalie Ouellette, an astrophysicist, iREx coordinator and communications scientist for the James Webb Telescope, tells us more about these remarkable images.
The images revealed clouds of gas and dust expelled by dying stars, galactic interactions and hitherto unseen stellar birth zones. What do you consider to be the most significant discoveries?
First, like the general public, I was struck by the beauty of the images—they're so exquisite! Second, it's hard to say which image is my favorite, I guess it's like choosing your favorite child.
The exoplanet spectrum is a favorite for me, because a Canadian instrument made it, and because it proved the presence of water and clouds, allowing us to rectify discoveries that had been based on less precise and sensitive data. Usually, when you're looking at exoplanets, the data don't always align; not so with James Webb, whose data turned out to be crisp and clean and revealed some incredible things.
Also, as my research focuses on galaxy formation and evolution, I found the Stephan Quintet image spectacular, giving new insight into how galactic interactions may have driven galaxy evolution in the early universe.
So these images are truly unprecedented for the human eye?
Yes, because they show light that the human eye cannot see. The Hubble telescope looked mainly at visible light, but James Webb looks into the infrared, enabling us to detect different phenomena.
For example, nebulae are somewhat mysterious objects because they are very dusty; there is a lot of gas blocking visible light. However, with infrared, we can penetrate the dust and obtain images like those of the Southern Ring and Carina nebulae.
Are the photos the result of some kind of manipulation?
Yes, and the team that produced the images for the unveiling is amazing. Remember, it's not an easy task to make invisible light visible. It required the work of artists and scientists who were able to translate infrared into the colors we can see. And the colors are not chosen at random: they serve to emphasize certain scientific and artistic aspects of the objects.
What will astrophysicists be able to do with the photos unveiled today?
There's still a lot of analysis to be done. The images were taken in just a few days, if not weeks. We're not even talking in terms of months!
It's like opening a box full of jewels. We want to look at everything, individually, carefully. There's a lot to discover in the images. It's as if there's a galaxy hidden in every pixel. The discoveries seem endless.
The telescope's scientific operations have also just begun. Scientists and astronomers from all over the world are beginning to take possession of the telescope for their own projects.
And what's next for you at iREx's, using the Webb?
One of the first and most exciting programs to be carried out with James Webb is the observation of the planets in the TRAPPIST-1 system. This is the biggest Canadian program for the first year, and is led by Université de Montréal Ph.D. student Olivia Lim. As with the exoplanet presented today, Olivia will be looking at the atmosphere of these exoplanets, which are rocky and could therefore resemble the Earth. We're looking for a bit of an Earth twin, and maybe we'll find it in the TRAPPIST-1 system.
Provided by University of Montreal
Artist's impression of the proposed LIFE mission. Credit: LIFE Initiative / ETH Zurich
The Large Interferometer for Exoplanets (LIFE) project is an ambitious plan to build a space telescope with four independent mirrors. The array would allow the individual mirrors to move closer or farther apart, similar to the way the Very Large Array (VLA) does with radio antennas. LIFE is still early in its planning stage, so it would likely be decades before it is built, but already the LIFE team is looking at ways it might discover life on other worlds. Much of this focuses on the detection of biogenic molecules in exoplanet atmospheres.
Earlier studies looked at simulations of how our solar system would appear as an exoplanetary system. If aliens used LIFE to view our solar system from 10 parsecs away (about 32 light-years), then the array would be able to directly observe Venus, Earth, and Mars. Using a process known as phase-space synthesis decomposition (PSSD), LIFE would also be able to detect several basic molecules in their atmospheres such as water and carbon dioxide.S
Of course, lots of potentially habitable worlds are expected to have atmospheric quantities of these molecules, but that doesn’t necessarily indicate the presence of life. A stronger case for life would be made if astronomers could detect more complex molecules that are biogenic in origin, meaning that they aren’t likely to form through any geological process.
This new study focuses on three types of molecules: nitrous oxide (N2O), also known as laughing gas, methyl chloride (CH3Cl), and methyl bromide (CH3Cl). All three of these are produced by ocean biology on Earth, so their presence in an exoplanet atmosphere would be a reasonable indication of life. Based on their simulations, the authors argue that LIFE would be able to detect these molecules in atmospheric atmospheres for worlds within 5 parsecs of Earth, and should be able to gather sufficient data within 10 – 100 days of observation time. A nearby system such as Proxima Centauri, just 4 light-years from Earth would take only a few days of observation. But even for a more distant system such as Trappist-1, which is 40 light-years away, LIFE has a decent chance of detection given enough time.
The Large Interferometer for Exoplanets is currently one project being considered by the European Space Agency, but there are other life-seeking projects being proposed as well. It will be years before LIFE or another mission will be approved, and a decade or more after that before it is launched. But studies such as these are needed to make those decisions. The search is on, and finding exoplanet life could be just a matter of time.
Reference: Matsuo, Taro, et al. “Large Interferometer For Exoplanets (LIFE)-XI. Phase-space synthesis decomposition for planet detection and characterization.” Astronomy & Astrophysics 678 (2023): A97.
Reference: Angerhausen, Daniel, et al. “Large Interferometer For Exoplanets (LIFE): XII. The Detectability of Capstone Biosignatures in the Mid-Infrared–Sniffing Exoplanetary Laughing Gas and Methylated Halogens.” arXiv preprint arXiv:2401.08492 (2024).
'Barbenheimer Star' that blew up 13 billion years ago defies explanation, baffling scientists
Scientists have discovered evidence of a massive star from the early universe that does not fit with our current understanding of the cosmos.
The ancient stellar oddball, which researchers have dubbed the "Barbenheimer Star," likely had a mix of elements in its core that has never been seen before — then, it died a seemingly impossible death while birthing an equally puzzling star in its place, a new study shows. (The name Barbenheimer is a reference to the contrasting films "Barbie" and "Oppenheimer" releasing on the same day last year.)
Researchers uncovered traces of the Barbenheimer Star after taking a closer look at J0931+0038, a distant red giant star. J0931 was first discovered in 1999 by the Sloan Digital Sky Survey (SDSS) — one of the largest and most detailed astronomical databases of the night sky — but had not been properly analyzed until now.
In a new study uploaded to the preprint server arXiv on Jan. 4, researchers turned the SDSS telescopes in New Mexico back toward J0931 and captured a detailed spectrum of the star's light, which was later verified by follow-up observations from the Giant Magellan Telescope in Chile. These spectra revealed that J0931 seemingly had an extremely odd metallicity, or chemical composition, with an unusually high concentration of heavy elements. (These results have not yet been peer-reviewed.)
Related: Aftermath of 2 star explosions captured in breathtaking new NASA image
Using the newly acquired data, the research team pieced together how J0931 formed via a process known as stellar archaeology. This revealed that the star was birthed from the supernova remnant of an even larger star — between 50 and 80 times more massive than the sun — that dates back as far as 13 billion years ago, only around 700 million years after the Big Bang.
The metallicity of the parent star (Barbenheimer) was likely equally as weird as that of J0931 before it blew up, which would have been completely different from other known stars in the early universe.
"We've never seen anything like this," study lead author Alex Ji, an astrophysicist at the University of Chicago, said in a statement. "Whatever happened back then, it must have been amazing."
J0931's metallicity was strange for three reasons. First, the star had unusually low levels of lighter elements such as magnesium, sodium and aluminum, which are normally more abundant in stars. Second, it had an unusually high amount of midweight elements such as iron, nickel and zinc. And finally, it had an "overabundance" of heavier elements like strontium and palladium, according to the researchers.
"We sometimes see one of these features at a time, but we've never before seen all of them in the same star," study co-author Jennifer Johnson, an astronomer at The Ohio State University, said in the statement.
Most stars have the reverse metallicity of J0931: They have higher levels of lighter elements and lower levels of midweight and heavier elements. This is because stars are made predominantly of hydrogen and helium, which fuse together in the stars' cores to create heavier elements. These new elements, which are much less abundant, eventually fuse into heavier and heavier elements.
It is therefore hard to explain why J0931 has such and abundance of heavy elements because it doesn't seem to have a high enough concentration of lighter elements to have created them.
"Amazingly, no existing model of element formation can explain what we see," said study co-author Sanjana Curtis, an astronomer at the University of California, Berkeley. It "almost seems self-contradictory," she said.
J0931's unusual metallicity would have partially been inherited from the ingredients that the Barbenheimer Star spit out when it exploded. This means that the parent star would likely have had a similarly inverted metallicity. This is even stranger, because in the early universe, stars shouldn't have existed long enough to have created such high concentrations of heavy elements, the team said.
But what's even stranger is that the Barbenheimer Star should have never gone supernova, the researchers wrote. In theory, a star with Barbenheimer's predicted mass should have collapsed into a black hole rather than exploding outward. At the moment, the study team cannot explain why this collapse didn't happen.
The only way for scientists to learn more about the Barbenhaimer Star and its bizarre composition is to search for other similar stellar oddballs from the early universe to uncover more pieces of this cosmic puzzle.
"The universe directed this movie, we are just the camera crew," study co-author Keith Hawkins, an astronomer at the University of Texas at Austin, said in the statement. "We don't yet know how the story will end."
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