NASA’s powerful James Webb Telescope has returned a new image of exploding supernova star Cassiopeia A, giving scientists never-before-seen detail, the agency said Friday.
April 7 (UPI) -- NASA's powerful James Webb Telescope has returned a new image of an exploding supernova star, giving scientists never-before-seen details, the space agency confirmed Friday.
The detailed photo provides greater insight into the Cassiopeia A supernova, which exploded 340 years ago, the youngest known remnant from such an explosion in our Milky Way Galaxy, NASA said in a statement.
The image, itself, comes from the telescope's Mid-Infrared Instrument, which provides greater detail than previous infrared imaging. That image is then translated into visible-light wavelengths.
The $10 billion telescope launched on Christmas Day in 2021. It has been sending back images since, giving astronomers "unprecedented views" of our own galaxy and beyond.
Friday's news gives researchers a more in-depth look at a prototypical supernova remnant after an explosion. Cassiopeia A already has been studied extensively by both ground and space-based observatories, including NASA's Chandra X-ray observatory, which was launched into space in 1999.
"Cas A represents our best opportunity to look at the debris field of an exploded star and run a kind of stellar autopsy to understand what type of star was there beforehand and how that star exploded," Purdue University researcher Danny Milisavljevic, principal investigator of the Webb program that captured the observations, said in a statement
"Compared to previous infrared images, we see incredible detail that we haven't been able to access before," said Princeton University scientist and co-investigator Tea Temim.
Webb reveals never-before-seen details in Cassiopeia A
Reports and ProceedingsIMAGE: CASSIOPEIA A (CAS A) IS A SUPERNOVA REMNANT LOCATED ABOUT 11,000 LIGHT-YEARS FROM EARTH IN THE CONSTELLATION CASSIOPEIA. IT SPANS APPROXIMATELY 10 LIGHT-YEARS. THIS NEW IMAGE USES DATA FROM WEBB’S MID-INFRARED INSTRUMENT (MIRI) TO REVEAL CAS A IN A NEW LIGHT. view more
CREDIT: CREDITS: NASA, ESA, CSA, D. D. MILISAVLJEVIC (PURDUE), T. TEMIM (PRINCETON), I. DE LOOZE (GHENT UNIVERSITY). IMAGE PROCESSING: J. DEPASQUALE (STSCI).
The explosion of a star is a dramatic event, but the remains the star leaves behind can be even more dramatic. A new mid-infrared image from NASA’s James Webb Space Telescope provides one stunning example. It shows the supernova remnant Cassiopeia A (Cas A), created by a stellar explosion seen from Earth 340 years ago. Cas A is the youngest known remnant from an exploding, massive star in our galaxy, which makes it a unique opportunity to learn more about how such supernovae occur.
“Cas A represents our best opportunity to look at the debris field of an exploded star and run a kind of stellar autopsy to understand what type of star was there beforehand and how that star exploded,” said Danny Milisavljevic of Purdue University in West Lafayette, Indiana, principal investigator of the Webb program that captured these observations.
“Compared to previous infrared images, we see incredible detail that we haven't been able to access before,” added Tea Temim of Princeton University in Princeton, New Jersey, a co-investigator on the program.
Cassiopeia A is a prototypical supernova remnant that has been widely studied by a number of ground-based and space-based observatories, including NASA’s Chandra X-ray Observatory. The multi-wavelength observations can be combined to provide scientists with a more comprehensive understanding of the remnant.
Dissecting the Image
The striking colors of the new Cas A image, in which infrared light is translated into visible-light wavelengths, hold a wealth of scientific information the team is just beginning to tease out. On the bubble’s exterior, particularly at the top and left, lie curtains of material appearing orange and red due to emission from warm dust. This marks where ejected material from the exploded star is ramming into surrounding circumstellar gas and dust.
Interior to this outer shell lie mottled filaments of bright pink studded with clumps and knots. This represents material from the star itself, which is shining due to a mix of various heavy elements, such as oxygen, argon, and neon, as well as dust emission.
“We’re still trying to disentangle all these sources of emission,” said Ilse De Looze of Ghent University in Belgium, another co-investigator on the program.
The stellar material can also be seen as fainter wisps near the cavity’s interior.
Perhaps most prominently, a loop represented in green extends across the right side of the central cavity. “We’ve nicknamed it the Green Monster in honor of Fenway Park in Boston. If you look closely, you’ll notice that it’s pockmarked with what look like mini-bubbles,” said Milisavljevic. “The shape and complexity are unexpected and challenging to understand.”
Origins of Cosmic Dust – and Us
Among the science questions that Cas A may help answer is: Where does cosmic dust come from? Observations have found that even very young galaxies in the early universe are suffused with massive quantities of dust. It’s difficult to explain the origins of this dust without invoking supernovae, which spew large quantities of heavy elements (the building blocks of dust) across space.
However, existing observations of supernovae have been unable to conclusively explain the amount of dust we see in those early galaxies. By studying Cas A with Webb, astronomers hope to gain a better understanding of its dust content, which can help inform our understanding of where the building blocks of planets and ourselves are created.
“In Cas A, we can spatially resolve regions that have different gas compositions and look at what types of dust were formed in those regions,” explained Temim.
Supernovae like the one that formed Cas A are crucial for life as we know it. They spread elements like the calcium we find in our bones and the iron in our blood across interstellar space, seeding new generations of stars and planets.
“By understanding the process of exploding stars, we’re reading our own origin story,” said Milisavljevic. “I’m going to spend the rest of my career trying to understand what’s in this data set.”
The Cas A remnant spans about 10 light-years and is located 11,000 light-years away in the constellation Cassiopeia.
The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
Twinkling stars fuel interstellar dust
Stars with variable luminosity found to influence supply of dust that made life
IMAGE: ARTIST’S IMPRESSION OF HOW ASYMPTOTIC GIANT BRANCH STARS EXERT PRESSURE ON SOLID MATTER. view more
CREDIT: ©2023 MIYATA, TACHIBANA, ET AL. CC-BY
Of the many different kinds of stars, asymptotic giant branch (AGB) stars, usually slightly larger and older than our own sun, are known producers of interstellar dust. Dusty AGBs are particularly prominent producers of dust, and the light they shine happens to vary widely. For the first time, a long-period survey has found the variable intensity of dusty AGBs coincides with variations in the amount of dust these stars produce. As this dust can lead to the creation of planets, its study can shed light on our own origins.
You’ve probably heard of the James Webb Space Telescope (JWST) which has been in the news lately. It’s famous for being the largest and most sensitive space telescope designed to observe infrared (IR) light. But long before the JWST took to the skies, two other IR space telescopes, AKARI and WISE, have been surveying the cosmos, both of which have ended their initial missions, but produced so much valuable data that astronomers are still finding new discoveries with it. The latest finding from that data by doctoral student Kengo Tachibana from the University of Tokyo’s Institute of Astronomy and his team, could have implications for the study of the origins of life itself.
“We study stars, and IR light from them is a key source of information that helps us unlock their secrets,” said Tachibana. “Until recently, most IR data was from very short-period surveys due to the lack of advanced dedicated platforms. But missions like AKARI and WISE have allowed us to take longer-period surveys of things. This means we can see how things might change over greater time periods, and what these changes might imply. Lately, we turned our attention to a certain class of star known as asymptotic giant branch stars, which are interesting because they are the main producers of interstellar dust.”
This interstellar dust is not the same stuff that accumulates on your floor when you forget to vacuum for a few days; it’s a name given to heavy elements that disperse from stars and lead to the formation of solid objects including planets. Although it’s long been known that AGBs, and especially so-called dusty AGBs, are the main producers of dust, it’s not known what the main drivers of dust production are and where we should be looking to find this out.
“Our latest study has pointed us in the right direction,” said Tachibana. “Thanks to long-period IR observations, we have found that the light from dusty AGBs varies with periods longer than several hundred days. We also found that the spherical shells of dust produced by and then ejected by these stars have concentrations of dust that vary in step with the stars’ changes in luminosity. Of the 169 dusty AGBs surveyed, no matter their variability period, the concentrations of dust around them would coincide. So, we’re certain these are connected.”
Finding a connection between the concentration of dust and the variability of stars’ brightness is just the first step in this investigation however. Now the team wishes to explore the possible physical mechanisms behind the production of dust. For this, they intend to monitor various AGB stars for many years continuously. The University of Tokyo is nearing completion of a large ground-based telescope project, the University of Tokyo Atacama Observatory, in Chile, which will be dedicated to making infrared observations.
Artist’s impression of an asymptotic giant branch star.
CREDIT
©2023 Miyata, Tachibana, et al. CC-BY
Journal article
Kengo TACHIBANA, Takashi MIYATA, Takafumi KAMIZUKA, Ryou OHSAWA, Satoshi TAKITA, Akiharu NAKAGAWA, Yoshifusa ITA and Mizuho UCHIYAMA, “Investigation of mid-infrared long-term variability of dusty AGB stars using multiepoch scan data of AKARI and WISE”, Publications of the Astronomical Society of Japan, DOI
Funding
This work was supported by JST SPRING, Grant Number JPMJSP2108.
About the University of Tokyo
The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 4,000 international students. Find out more at www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.
JOURNAL
Publications of the Astronomical Society of Japan
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Investigation of mid-infrared long-term variability of dusty AGB stars using multiepoch scan data of AKARI and WISE
ARTICLE PUBLICATION DATE
7-Apr-2023
How to see the invisible: Using the dark matter distribution to test our cosmological model
A Princeton-led team of astrophysicists has measured a value for the “clumpiness” of the universe’s dark matter that suggests the standard cosmological model might need to be revised
Reports and ProceedingsIMAGE: PRINCETON ASTROPHYSICISTS MICHAEL STRAUSS AND ROOHI DALAL ARE PART OF AN INTERNATIONAL TEAM THAT TESTED THE STANDARD COSMOLOGICAL MODEL BY MEASURING LENSING AROUND PATCHES OF DARK MATTER. STRAUSS IS CHAIR OF PRINCETON’S DEPARTMENT OF ASTROPHYSICAL SCIENCES AND ONE OF THE LEADERS OF THE HYPER-SUPRIME CAMERA TEAM ON THE SUBARU TELESCOPE, AND DALAL IS A GRADUATE STUDENT ON HIS TEAM WHO IS FIRST AUTHOR ON ONE OF A SERIES OF NEW PAPERS FROM THE HSC TEAM. view more
CREDIT: STEPHANIE N. REIF, PRINCETON UNIVERSITY
It feels like a classical paradox: How do you see the invisible? But for modern astronomers, it is a very real challenge: How do you measure dark matter, which by definition emits no light?
The answer: You see how it impacts things that you can see. In the case of dark matter, astronomers watch how light from distant galaxies bends around it.
An international team of astrophysicists and cosmologists have spent the past year teasing out the secrets of this elusive material, using sophisticated computer simulations and the observations from the one of the most powerful astronomical cameras in the world, the Hyper Suprime-Cam (HSC). The team is led by astronomers from Princeton University and the astronomical communities of Japan and Taiwan, using data from the first three years of the HSC sky survey, a wide-field imaging survey carried out with the 8.2-meter Subaru telescope on the summit of Maunakea in Hawai’i. Subaru is operated by the National Astronomical Observatory of Japan; its name is the Japanese word for the cluster of stars we call the Pleiades.
The team presented their findings at a webinar attended by more than 200 people, and they will share their work at the "Future Science with CMB x LSS" conference in Japan.
“Our overall goal is to measure some of the most fundamental properties of our universe,” said Roohi Dalal, a graduate student in astrophysics at Princeton. “We know that dark energy and dark matter make up 95% of our universe, but we understand very little about what they actually are and how they’ve evolved over the history of the universe. Clumps of dark matter distort the light of distant galaxies through weak gravitational lensing, a phenomenon predicted by Einstein’s General Theory of Relativity. This distortion is a really, really small effect; the shape of a single galaxy is distorted by an imperceptible amount. But when we make that measurement for 25 million galaxies, we’re able to measure the distortion with quite high precision.”
To jump to the punchline: The team has measured a value for the “clumpiness” of the universe’s dark matter (known to cosmologists as “S8”) of 0.776, which aligns with values that other gravitational lensing surveys have found in looking at the relatively recent universe — but it does not align with the value of 0.83 derived from the Cosmic Microwave Background, which dates back to the universe’s origins.
The gap between these two values is small, but as more and more studies confirm each of the two values, it doesn’t appear to be accidental. The other possibilities are that there’s some as-yet unrecognized error or mistake in one of these two measurements or the standard cosmological model is incomplete in some interesting way.
“We’re still being fairly cautious here,” said Michael Strauss, chair of Princeton’s Department of Astrophysical Sciences and one of the leaders of the HSC team. “We’re not saying that we’ve just discovered that modern cosmology is all wrong, because, as Roohi has emphasized, the effect that we’re measuring is a very subtle one. Now, we think we’ve done the measurement right. And the statistics show that there’s only a one in 20 chance that it’s just due to chance, which is compelling but not completely definitive. But as we in the astronomy community come to the same conclusion over multiple experiments, as we keep on doing these measurements, perhaps we’re finding that it’s real.”
This cluster of stars, known as the Pleiades to Western astronomers, is known as Subaru in Japan and gives its name to the 8.2-meter Subaru telescope on the summit of Maunakea in Hawai’i. Subaru is operated by the National Astronomical Observatory of Japan.
CREDIT
NASA, ESA, AURA/Caltech, Palomar Observatory
Hiding and uncovering the data
The idea that some change is needed in the standard cosmological model, that there is some fundamental piece of cosmology yet to be discovered, is a deliciously enticing one for some scientists.
“We are human beings, and we do have preferences. That’s why we do what we call a ‘blinded’ analysis,” Strauss said. “Scientists have become self-aware enough to know that we will bias ourselves, no matter how careful we are, unless we carry out our analysis without allowing ourselves to know the results until the end. For me, I would love to really find something fundamentally new. That would be truly exciting. But because I am prejudiced in that direction, we want to be very careful not to let that influence any analysis that we do.”
To protect their work from their biases, they quite literally hid their results from themselves and their colleagues — month after month after month.
“I worked on this analysis for a year and didn’t get to see the values that were coming out,” said Dalal.
The team even added an extra obfuscating layer: they ran their analyses on three different galaxy catalogs, one real and two with numerical values offset by random values.
“We didn’t know which of them was real, so even if someone did accidentally see the values, we wouldn’t know if the results were based on the real catalog or not,” she said.
On February 16, the international team gathered together on Zoom — in the evening in Princeton, in the morning in Japan and Taiwan — for the “unblinding.”
“It felt like a ceremony, a ritual, that we went through,” Strauss said. “We unveiled the data, and ran our plots, immediately we saw it was great. Everyone went, ‘Oh, whew!’ and everyone was very happy.”
Dalal and her roommate popped a bottle of champagne that night.
A huge survey with the world’s largest telescope camera
HSC is the largest camera on a telescope of its size in the world, a mantle it will hold until the Vera C. Rubin Observatory currently under construction in the Chilean Andes, begins the Legacy Survey of Space and Time (LSST) in late 2024. In fact, the raw data from HSC is processed with the software designed for LSST. “It is fascinating to see that our software pipelines are able to handle such large quantities of data well ahead of LSST,” said Andrés Plazas, an associate research scholar at Princeton.
The survey that the research team used covers about 420 square degrees of the sky, about the equivalent of 2000 full moons. It’s not a single contiguous chunk of sky, but split among six different pieces, each about the size that you could cover with an outstretched fist. The 25 million galaxies they surveyed are so distant that instead of seeing these galaxies as they are today, the HSC recorded how they were billions of years ago.
Each of these galaxies glows with the fires of tens of billions of suns, but because they are so far away, they are extremely faint, as much as 25 million times fainter than the faintest stars we can see with the naked eye.
“It is extremely exciting to see these results from HSC collaboration, especially as this data is closest to what we expect from Rubin Observatory, which the community is working towards together,” said cosmologist Alexandra Amon, a Senior Kavli Fellow at Cambridge University and a senior researcher at Trinity College, who was not involved in this research. “Their deep survey makes for beautiful data. For me, it is intriguing that HSC, like the other independent weak lensing surveys, point to a low value for S8 — it’s important validation, and exciting that these tensions and trends force us to pause and think about what that data is telling us about our Universe!”
The standard cosmological model
The standard model of cosmology is “astonishingly simple” in some ways, explained Andrina Nicola of the University of Bonn, who advised Dalal on this project when she was a postdoctoral scholar at Princeton. The model posits that the universe is made up of only four basic constituents: ordinary matter (atoms, mostly hydrogen and helium), dark matter, dark energy and photons.
According to the standard model, the universe has been expanding since the Big Bang 13.8 billion years ago: it started out almost perfectly smooth, but the pull of gravity on the subtle fluctuations in the universe has caused structure — galaxies enveloped in dark matter clumps — to form. In the present-day universe, the relative contributions of ordinary matter, dark matter, dark energy are about 5%, 25% and 70%, plus a tiny contribution from photons.
The standard model is defined by only a handful of numbers: the expansion rate of the universe; a measure of how clumpy the dark matter is (S8); the relative contributions of the constituents of the universe (the 5%, 25%, 70% numbers above); the overall density of the universe; and a technical quantity describing how the clumpiness of the universe on large scales relates to that on small scales.
“And that’s basically it!” Strauss said. “We, the cosmological community, have converged on this model, which has been in place since the early 2000s.”
Cosmologists are eager to test this model by constraining these numbers in various ways, such as by observing the fluctuations in the Cosmic Microwave Background (which in essence is the universe’s baby picture, capturing how it looked after its first 400,000 years), modeling the expansion history of the universe, measuring the clumpiness of the universe in the relatively recent past, and others.
“We’re confirming a growing sense in the community that there is a real discrepancy between the measurement of clumping in the early universe (measured from the CMB) and that from the era of galaxies, ‘only’ 9 billion years ago,” said Arun Kannawadi, an associate research scholar at Princeton who was involved in the analysis.
Five lines of attack
Dalal’s work does a so-called Fourier-space analysis; a parallel real-space analysis was led by Xiangchong Li of Carnegie Mellon University, who worked in close collaboration with Rachel Mandelbaum, who completed her physics A.B. in 2000 and her Ph.D. in 2006, both from Princeton. A third analysis, a so-called 3x2-point analysis, takes a different approach of measuring the gravitational lensing signal around individual galaxies, to calibrate the amount of dark matter associated with each galaxy. That analysis was led by Sunao Sugiyama of the University of Tokyo, Hironao Miyatake (a former Princeton postdoctoral fellow) of Nagoya University and Surhud More of the Inter-University Centre for Astronomy and Astrophysics in Pune, India.
These five sets of analyses each use the HSC data to come to the same conclusion about S8.
Doing both the real-space analysis and the Fourier-space analysis “was sort of a sanity check,” said Dalal. She and Li worked closely to coordinate their analyses, using blinded data. Any discrepancies between those two would say that the researchers’ methodology was wrong. “It would tell us less about astrophysics and more about how we might have screwed up,” Dalal said.
“We didn’t know until the unblinding that two results were bang-on identical,” she said. “It felt miraculous.”
Sunao added: “Our 3x2-point analysis combines the weak lensing analysis with the clustering of galaxies. Only after unblinding did we know that our results were in beautiful agreement with those of Roohi and Xiangchong. The fact that all these analyses are giving the same answer gives us confidence that we’re doing something right!”
Learn more at https://hsc-release.mtk.nao.ac.jp/doc/index.php/. This research will be presented at "Future Science with CMB x LSS," a conference running from April 10-14 at Yukawa Institute for Theoretical Physics, Kyoto University. This research was supported by the National Science Foundation Graduate Research Fellowship Program (DGE-2039656); the National Astronomical Observatory of Japan; the Kavli Institute for the Physics and Mathematics of the Universe; the University of Tokyo; the High Energy Accelerator Research Organization (KEK); the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan; Princeton University; the FIRST program from the Japanese Cabinet Office; the Ministry of Education, Culture, Sports, Science and Technology (MEXT); the Japan Society for the Promotion of Science; the Japan Science and Technology Agency; the Toray Science Foundation; and the Vera C. Rubin Observatory.
NASA’s high-resolution air quality control instrument launches
IMAGE: NASA’S TROPOSPHERIC EMISSIONS: MONITORING OF POLLUTION (TEMPO) INSTRUMENT LAUNCHED 12:30 A.M. EDT FRIDAY, APRIL 7 AS A PAYLOAD ON INTELSAT 40E ABOARD A SPACEX FALCON 9 ROCKET FROM CAPE CANAVERAL SPACE FORCE STATION IN FLORIDA. view more
CREDIT: CREDITS: NASA
A NASA instrument to provide unprecedented resolution of monitoring major air pollutants – down to four square miles – lifted off on its way to geostationary orbit at 12:30 a.m. EDT Friday. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument will improve life on Earth by revolutionizing the way scientists observe air quality from space.
"The TEMPO mission is about more than just studying pollution – it's about improving life on Earth for all. By monitoring the effects of everything from rush-hour traffic to pollution from forest fires and volcanoes, NASA data will help improve air quality across North America and protect our planet,” said NASA Administrator Bill Nelson.
NASA’s TEMPO launched from Cape Canaveral Space Force Station in Florida atop a SpaceX Falcon 9 rocket. The instrument is a payload on the satellite Intelsat 40E, which separated from the rocket approximately 32 minutes after launch. Signal acquisition occurred at 1:14 a.m. TEMPO commissioning activities will begin in late May or early June.
From a fixed geostationary orbit above the equator, TEMPO will be the first space-based instrument to measure air quality over North America hourly during the daytime and at spatial regions of several square miles – far better than existing limits of about 100 square miles in the U.S. TEMPO data will play an important role in the scientific analysis of pollution, including studies of rush hour pollution, the potential for improved air quality alerts, the effects of lightning on ozone, the movement of pollution from forest fires and volcanoes, and even the effects of fertilizer application.
“NASA makes data from instruments like TEMPO easily accessible to everyone,” said Karen St. Germain, division director for NASA’s Earth Sciences Division. “Which means that everyone from community and industry leaders to asthma sufferers are going to be able to access air quality information at a higher level of detail – in both time and location - than they’ve ever been able to before. And that also provides the information needed to start addressing one of the most pressing human health challenges.”
TEMPO’s observations will dramatically improve the scientific data record on air pollution – including ozone, nitrogen oxide, sulfur dioxide and formaldehyde – not only over the continental United States, but also Canada, Mexico, Cuba, the Bahamas, and part of the island of Hispaniola.
"Our TEMPO slogan is 'It's about time,' which hints at TEMPO's ability to provide hourly air pollution data," said Xiong Liu, deputy principal investigator for TEMPO at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts. "After working on the TEMPO for more than 10 years, it is about time to launch TEMPO to produce real TEMPO data and start the new era of air quality monitoring over North America."
From its geostationary orbit – a high Earth orbit that allows satellites to match Earth's rotation – TEMPO also will form part of an air quality satellite virtual constellation that will track pollution around the Northern Hemisphere. South Korea's Geostationary Environment Monitoring Spectrometer, the first instrument in the constellation, launched into space in 2020 on the Korean Aerospace Research Institute GEO-KOMPSAT-2B satellite, and is measuring pollution over Asia. The ESA (European Space Agency) Sentinel-4 satellite, scheduled to launch in 2024, will make measurements over Europe and North Africa.
“This marks a new era in our ability to observe air pollution over North America, including the entire continental United States,” said Barry Lefer, TEMPO program scientist and tropospheric composition program manager for NASA. “It’s also opening the door for us to work more closely with our international partners to better understand global air quality and its transport.”
The instrument was built by Ball Aerospace and integrated onto Intelsat 40E by Maxar.
To learn more about NASA’s Earth sciences, visit:
Hubble sees possible runaway black hole creating a trail of stars
IMAGE: THIS IS AN ARTIST'S IMPRESSION OF A RUNAWAY SUPERMASSIVE BLACK HOLE THAT WAS EJECTED FROM ITS HOST GALAXY AS A RESULT OF A TUSSLE BETWEEN IT AND TWO OTHER BLACK HOLES. AS THE BLACK HOLE PLOWS THROUGH INTERGALACTIC SPACE IT COMPRESSES TENUOUS GAS IN FRONT TO IT. THIS PRECIPITATES THE BIRTH OF HOT BLUE STARS. THIS ILLUSTRATION IS BASED ON HUBBLE SPACE TELESCOPE OBSERVATIONS OF A 200,000-LIGHT-YEAR-LONG "CONTRAIL" OF STARS BEHIND AN ESCAPING BLACK HOLE. view more
CREDIT: NASA, ESA, LEAH HUSTAK (STSCI)
There's an invisible monster on the loose, barreling through intergalactic space so fast that if it were in our solar system, it could travel from Earth to the Moon in 14 minutes. This supermassive black hole, weighing as much as 20 million Suns, has left behind a never-before-seen 200,000-light-year-long "contrail" of newborn stars, twice the diameter of our Milky Way galaxy. It's likely the result of a rare, bizarre game of galactic billiards among three massive black holes.
Rather than gobbling up stars ahead of it, like a cosmic Pac-Man, the speedy black hole is plowing into gas in front of it to trigger new star formation along a narrow corridor. The black hole is streaking too fast to take time for a snack. Nothing like it has ever been seen before, but it was captured accidentally by NASA's Hubble Space Telescope.
"We think we're seeing a wake behind the black hole where the gas cools and is able to form stars. So, we're looking at star formation trailing the black hole," said Pieter van Dokkum of Yale University in New Haven, Connecticut. "What we're seeing is the aftermath. Like the wake behind a ship we're seeing the wake behind the black hole." The trail must have lots of new stars, given that it is almost half as bright as the host galaxy it is linked to.
The black hole lies at one end of the column, which stretches back to its parent galaxy. There is a remarkably bright knot of ionized oxygen at the outermost tip of the column. Researchers believe gas is probably being shocked and heated from the motion of the black hole hitting the gas, or it could be radiation from an accretion disk around the black hole. "Gas in front of it gets shocked because of this supersonic, very high-velocity impact of the black hole moving through the gas. How it works exactly is not really known," said van Dokkum.
"This is pure serendipity that we stumbled across it," van Dokkum added. He was looking for globular star clusters in a nearby dwarf galaxy. "I was just scanning through the Hubble image and then I noticed that we have a little streak. I immediately thought, 'oh, a cosmic ray hitting the camera detector and causing a linear imaging artifact.' When we eliminated cosmic rays we realized it was still there. It didn't look like anything we've seen before."
Because it was so weird, van Dokkum and his team did follow-up spectroscopy with the W. M. Keck Observatories in Hawaii. He describes the star trail as "quite astonishing, very, very bright and very unusual." This led to the conclusion that he was looking at the aftermath of a black hole flying through a halo of gas surrounding the host galaxy.
This intergalactic skyrocket is likely the result of multiple collisions of supermassive black holes. Astronomers suspect the first two galaxies merged perhaps 50 million years ago. That brought together two supermassive black holes at their centers. They whirled around each other as a binary black hole.
Then another galaxy came along with its own supermassive black hole. This follows the old idiom: "two's company and three's a crowd." The three black holes mixing it up led to a chaotic and unstable configuration. One of the black holes robbed momentum from the other two black holes and got thrown out of the host galaxy. The original binary may have remained intact, or the new interloper black hole may have replaced one of the two that were in the original binary, and kicked out the previous companion.
When the single black hole took off in one direction, the binary black holes shot off in the opposite direction. There is a feature seen on the opposite side of the host galaxy that might be the runaway binary black hole. Circumstantial evidence for this is that there is no sign of an active black hole remaining at the galaxy’s core. The next step is to do follow-up observations with NASA's James Webb Space Telescope and the Chandra X-ray Observatory to confirm the black hole explanation.
NASA's upcoming Nancy Grace Roman Space Telescope will have a wide-angle view of the universe with Hubble's exquisite resolution. As a survey telescope, the Roman observations might find more of these rare and improbable "star streaks" elsewhere in the universe. This may require machine learning using algorithms that are very good at finding specific weird shapes in a sea of other astronomical data, according to van Dokkum.
The research paper will be published on April 6 in The Astrophysical Journal Letters.
The Hubble Space Telescope is a project of international cooperation between NASA and ESA. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.
RUNAWAY BLACK HOLE NEAR RCP28
NASA/GODDARD SPACE FLIGHT CENTER
This Hubble Space Telescope archival photo captures a curious linear feature that is so unusual it was first dismissed as an imaging artifact from Hubble's cameras. But follow-up spectroscopic observations reveal it is a 200,000-light-year-long chain of young blue stars. A supermassive black hole lies at the tip of the bridge at lower left. The black hole was ejected from the galaxy at upper right. It compressed gas in its wake to leave a long trail of young blue stars. Nothing like this has ever been seen before in the universe. This unusual event happened when the universe was approximately half its current age.
CREDIT
NASA, ESA, Pieter van Dokkum (Yale); Image Processing: Joseph DePasquale (STScI)
JOURNAL
The Astrophysical Journal Letters
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
A Candidate Runaway Supermassive Black Hole Identified by Shocks and Star Formation in its Wake
ARTICLE PUBLICATION DATE
6-Apr-2023
NASA’s Webb scores another ringed world with new image of Uranus
IMAGE: THIS ZOOMED-IN IMAGE OF URANUS, CAPTURED BY WEBB’S NEAR-INFRARED CAMERA (NIRCAM) FEB. 6, 2023, REVEALS STUNNING VIEWS OF THE PLANET’S RINGS. THE PLANET DISPLAYS A BLUE HUE IN THIS REPRESENTATIVE-COLOR IMAGE, MADE BY COMBINING DATA FROM TWO FILTERS (F140M, F300M) AT 1.4 AND 3.0 MICRONS, WHICH ARE SHOWN HERE AS BLUE AND ORANGE, RESPECTIVELY. DOWNLOAD THE FULL-RESOLUTION VERSION FROM THE SPACE TELESCOPE SCIENCE INSTITUTE. view more
CREDIT: CREDITS: NASA, ESA, CSA, STSCI. IMAGE PROCESSING: J. DEPASQUALE (STSCI)
Following in the footsteps of the Neptune image released in 2022, NASA’s James Webb Space Telescope has taken a stunning image of the solar system’s other ice giant, the planet Uranus. The new image features dramatic rings as well as bright features in the planet’s atmosphere. The Webb data demonstrates the observatory’s unprecedented sensitivity for the faintest dusty rings, which have only ever been imaged by two other facilities: the Voyager 2 spacecraft as it flew past the planet in 1986, and the Keck Observatory with advanced adaptive optics.
The seventh planet from the Sun, Uranus is unique: It rotates on its side, at roughly a 90-degree angle from the plane of its orbit. This causes extreme seasons since the planet’s poles experience many years of constant sunlight followed by an equal number of years of complete darkness. (Uranus takes 84 years to orbit the Sun.) Currently, it is late spring for the northern pole, which is visible here; Uranus’ northern summer will be in 2028. In contrast, when Voyager 2 visited Uranus it was summer at the south pole. The south pole is now on the ‘dark side’ of the planet, out of view and facing the darkness of space.
This infrared image from Webb’s Near-Infrared Camera (NIRCam) combines data from two filters at 1.4 and 3.0 microns, which are shown here in blue and orange, respectively. The planet displays a blue hue in the resulting representative-color image.
When Voyager 2 looked at Uranus, its camera showed an almost featureless blue-green ball in visible wavelengths. With the infrared wavelengths and extra sensitivity of Webb we see more detail, showing how dynamic the atmosphere of Uranus really is.
On the right side of the planet there’s an area of brightening at the pole facing the Sun, known as a polar cap. This polar cap is unique to Uranus – it seems to appear when the pole enters direct sunlight in the summer and vanish in the fall; these Webb data will help scientists understand the currently mysterious mechanism. Webb revealed a surprising aspect of the polar cap: a subtle enhanced brightening at the center of the cap. The sensitivity and longer wavelengths of Webb’s NIRCam may be why we can see this enhanced Uranus polar feature when it has not been seen as clearly with other powerful telescopes like the Hubble Space Telescope and Keck Observatory.
At the edge of the polar cap lies a bright cloud as well as a few fainter extended features just beyond the cap’s edge, and a second very bright cloud is seen at the planet’s left limb. Such clouds are typical for Uranus in infrared wavelengths, and likely are connected to storm activity.
This planet is characterized as an ice giant due to the chemical make-up of its interior. Most of its mass is thought to be a hot, dense fluid of "icy" materials – water, methane, and ammonia – above a small rocky core.
Uranus has 13 known rings and 11 of them are visible in this Webb image. Some of these rings are so bright with Webb that when they are close together, they appear to merge into a larger ring. Nine are classed as the main rings of the planet, and two are the fainter dusty rings (such as the diffuse zeta ring closest to the planet) that weren’t discovered until the 1986 flyby by Voyager 2. Scientists expect that future Webb images of Uranus will reveal the two faint outer rings that were discovered with Hubble during the 2007 ring-plane crossing.
Webb also captured many of Uranus’ 27 known moons (most of which are too small and faint to be seen here); the six brightest are identified in the wide-view image. This was only a short, 12-minute exposure image of Uranus with just two filters. It is just the tip of the iceberg of what Webb can do when observing this mysterious planet. In 2022, the National Academies of Sciences, Engineering, and Medicine identified Uranus science as a priority in its 2023-2033 Planetary Science and Astrobiology decadal survey. Additional studies of Uranus are happening now, and more are planned in Webb’s first year of science operations.
The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
This wider view of the Uranian system with Webb’s NIRCam instrument features the planet Uranus as well as six of its 27 known moons (most of which are too small and faint to be seen in this short exposure). A handful of background objects, including many galaxies, are also seen.
CREDIT
Credits: NASA, ESA, CSA, STScI. Image processing: J. DePasquale (STScI)
New book explores possibilities of colonizing planets, moons and beyond
New Worlds: Colonizing Planets, Moons and Beyond
Book AnnouncementDan Răzvan Popoviciu new book New Worlds: Colonizing Planets, Moons and Beyond (published by Bentham Science) explores the possibilities of transforming humanity into a multi-planetary species, while also sounding an alarm about our long-term future. It emphasizes the importance of efficiently using Earth's resources and expanding beyond the planet's borders.
In the book, Popoviciu discusses how various planets, moons, and asteroids in the Solar System can provide important resources and become potential new home worlds for humans. The author goes beyond simple colonization and discusses solutions for terraforming these worlds, making them habitable for human descendants. He suggests that the technological solutions needed for terraforming are within reach and can be accomplished with the necessary willpower.
He also highlights the importance of researching the working mechanisms of the Universe, which is crucial for accessing other planetary systems. The book concludes by emphasizing the need for a synergistic approach to settling the Cosmos, using all available methods simultaneously to lower costs and the necessary time.
With ten captivating chapters, the book delves into the economic and demographic reasons driving the push for space exploration and settlement and exciting technical and ecological solutions that can improve life on Earth. This book covers everything from terraforming Mars and other planets like Venus to colonizing the outer reaches of our solar system and beyond. The author also dives into ethical considerations that support the expansion of humanity beyond our planet. New Worlds: Colonizing Planets, Moons and Beyond is an informative and essential read for anyone fascinated by the idea of space exploration and colonization.
