Jump to content

NASA’s Webb Identifies Tiniest Free-Floating Brown Dwarf


NASA

Recommended Posts

  • Publishers
6 Min Read

NASA’s Webb Identifies Tiniest Free-Floating Brown Dwarf

Image showing wispy pink-purple filaments and a scattering of stars.
Webb Telescope's Near-Infrared Camera shows the central portion of the star cluster IC 348.
Credits: NASA, ESA, CSA, STScI, K. Luhman (Penn State University), and C. Alves de Oliveira (ESA)

Brown dwarfs are objects that straddle the dividing line between stars and planets. They form like stars, growing dense enough to collapse under their own gravity, but they never become dense and hot enough to begin fusing hydrogen and turn into a star. At the low end of the scale, some brown dwarfs are comparable with giant planets, weighing just a few times the mass of Jupiter.

What are the smallest stars?

Astronomers are trying to determine the smallest object that can form in a star-like manner. A team using NASA’s James Webb Space Telescope has identified the new record-holder: a tiny, free-floating brown dwarf with only three to four times the mass of Jupiter.

“One basic question you’ll find in every astronomy textbook is, what are the smallest stars? That’s what we’re trying to answer,” explained lead author Kevin Luhman of Pennsylvania State University.

Search Strategy

To locate this newfound brown dwarf, Luhman and his colleague, Catarina Alves de Oliveira, chose to study the star cluster IC 348, located about 1,000 light-years away in the Perseus star-forming region. This cluster is young, only about 5 million years old. As a result, any brown dwarfs would still be relatively bright in infrared light, glowing from the heat of their formation.

The team first imaged the center of the cluster using Webb’s NIRCam (Near-Infrared Camera) to identify brown dwarf candidates from their brightness and colors. They followed up on the most promising targets using Webb’s NIRSpec (Near-Infrared Spectrograph) microshutter array.

Image: Star Cluster IC438

Image showing wispy pink-purple filaments and a scattering of stars.
This image from the NIRCam (Near-Infrared Camera) instrument on NASA’s James Webb Space Telescope shows the central portion of the star cluster IC 348. The wispy curtains filling the image are interstellar material reflecting the light from the cluster’s stars – what is known as a reflection nebula. The material also includes carbon-containing molecules known as polycyclic aromatic hydrocarbons, or PAHs. Winds from the most massive stars in the cluster may help sculpt the large loop seen on the right side of the field of view.
NASA, ESA, CSA, STScI, K. Luhman (Penn State University), and C. Alves de Oliveira (ESA)

Webb’s infrared sensitivity was crucial, allowing the team to detect fainter objects than ground-based telescopes. In addition, Webb’s sharp vision enabled them to determine which red objects were pinpoint brown dwarfs and which were blobby background galaxies.

This winnowing process led to three intriguing targets weighing three to eight Jupiter masses, with surface temperatures ranging from 1,500 to 2,800 degrees Fahrenheit (830 to 1,500 degrees Celsius). The smallest of these weighs just three to four times Jupiter, according to computer models.

Explaining how such a small brown dwarf could form is theoretically challenging. A heavy and dense cloud of gas has plenty of gravity to collapse and form a star. However, because of its weaker gravity, it should be more difficult for a small cloud to collapse to form a brown dwarf, and that is especially true for brown dwarfs with the masses of giant planets.

“It’s pretty easy for current models to make giant planets in a disk around a star,” said Catarina Alves de Oliveira of ESA (European Space Agency), principal investigator on the observing program. “But in this cluster, it would be unlikely this object formed in a disk, instead forming like a star, and three Jupiter masses is 300 times smaller than our Sun. So we have to ask, how does the star formation process operate at such very, very small masses?”

A Mystery Molecule

In addition to giving clues about the star-formation process, tiny brown dwarfs also can help astronomers better understand exoplanets. The least massive brown dwarfs overlap with the largest exoplanets; therefore, they would be expected to have some similar properties. However, a free-floating brown dwarf is easier to study than a giant exoplanet since the latter is hidden within the glare of its host star.

Two of the brown dwarfs identified in this survey show the spectral signature of an unidentified hydrocarbon, or molecule containing both hydrogen and carbon atoms. The same infrared signature was detected by NASA’s Cassini mission in the atmospheres of Saturn and its moon Titan. It has also been seen in the interstellar medium, or gas between stars.

“This is the first time we’ve detected this molecule in the atmosphere of an object outside our solar system,” explained Alves de Oliveira. “Models for brown dwarf atmospheres don’t predict its existence. We’re looking at objects with younger ages and lower masses than we ever have before, and we’re seeing something new and unexpected.”

Image: Three Brown Dwarfs

Image of wispy pink-purple hair-like filaments and a scattering of stars, with three image details pulled out in square boxes stacked vertically along the right.
This image from the NIRCam (Near-Infrared Camera) instrument on NASA’s James Webb Space Telescope shows the central portion of the star cluster IC 348. Astronomers combed the cluster in search of tiny, free-floating brown dwarfs: objects too small to be stars but larger than most planets. They found three brown dwarfs that are less than eight times the mass of Jupiter, which are circled in the main image and shown in the detailed pullouts at right. The smallest weighs just three to four times Jupiter, challenging theories for star formation.
NASA, ESA, CSA, STScI, K. Luhman (Penn State University), and C. Alves de Oliveira (ESA)

Brown Dwarf or Rogue Planet?

Since the objects are well within the mass range of giant planets, it raises the question of whether they are actually brown dwarfs, or if they’re really rogue planets that were ejected from planetary systems. While the team can’t rule out the latter, they argue that they are far more likely to be a brown dwarf than an ejected planet.

An ejected giant planet is unlikely for two reasons. First, such planets are uncommon in general compared to planets with smaller masses. Second, most stars are low-mass stars, and giant planets are especially rare among those stars. As a result, it’s unlikely that most of the stars in IC 348 (which are low-mass stars) are capable of producing such massive planets. In addition, since the cluster is only 5 million years old, there probably hasn’t been enough time for giant planets to form and then be ejected from their systems.

The discovery of more such objects will help clarify their status. Theories suggest that rogue planets are more likely to be found in the outskirts of a star cluster, so expanding the search area may identify them if they exist within IC 348.

Future work may also include longer surveys that can detect fainter, smaller objects. The short survey conducted by the team was expected to detect objects as small as twice the mass of Jupiter. Longer surveys could easily reach one Jupiter mass.

These observations were taken as part of Guaranteed Time Observation program 1229. The results were published in the Astronomical Journal.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing 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.

Media Contacts

Laura Betzlaura.e.betz@nasa.gov, Rob Gutrorob.gutro@nasa.gov
NASA’s  Goddard Space Flight Center, Greenbelt, Md.

Hannah Braun hbraun@stsci.edu , Christine Pulliamcpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.

Downloads

Download full resolution images for this article from the Space Telescope Science Institute.

Read/Download the research results released in The Astronomical Journal.

Right click the images in this article to open a larger version in a new tab/window.

Related Information

Lifecycle of Stars

More Webb News – https://science.nasa.gov/mission/webb/latestnews/

More Webb Images – https://science.nasa.gov/mission/webb/multimedia/images/

Webb Mission Page – https://science.nasa.gov/mission/webb/

Related For Kids

How do we weigh planets?

What is a nebula?

What is the Webb Telescope?

SpacePlace for Kids

En Español

Ciencia de la NASA

NASA en español 

Space Place para niños

6 Min Read

NASA’s Webb Identifies Tiniest Free-Floating Brown Dwarf

Image showing wispy pink-purple filaments and a scattering of stars.
This image from the NIRCam (Near-Infrared Camera) instrument on NASA’s James Webb Space Telescope shows the central portion of the star cluster IC 348. The wispy curtains filling the image are interstellar material reflecting the light from the cluster’s stars – what is known as a reflection nebula. The material also includes carbon-containing molecules known as polycyclic aromatic hydrocarbons, or PAHs. Winds from the most massive stars in the cluster may help sculpt the large loop seen on the right side of the field of view.
Credits: NASA, ESA, CSA, STScI, K. Luhman (Penn State University), and C. Alves de Oliveira (ESA)

View the full article

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By European Space Agency
      For the first time, a phenomenon astronomers have long hoped to image directly has been captured by the NASA/ESA/CSA James Webb Space Telescope’s Near-InfraRed Camera (NIRCam). In this stunning image of the Serpens Nebula, the discovery lies in the northern area of this young, nearby star-forming region.
      View the full article
    • By NASA
      6 Min Read First of Its Kind Detection Made in Striking New Webb Image
      The Serpens Nebula from NASA’s James Webb Space Telescope. Alignment of bipolar jets confirms star formation theories
      For the first time, a phenomenon astronomers have long hoped to directly image has been captured by NASA’s James Webb Space Telescope’s Near-Infrared Camera (NIRCam). In this stunning image of the Serpens Nebula, the discovery lies in the northern area (seen at the upper left) of this young, nearby star-forming region.
      Astronomers found an intriguing group of protostellar outflows, formed when jets of gas spewing from newborn stars collide with nearby gas and dust at high speeds. Typically these objects have varied orientations within one region. Here, however, they are slanted in the same direction, to the same degree, like sleet pouring down during a storm.
      Image: Serpens Nebula (NIRCam)
      In this image of the Serpens Nebula from NASA’s James Webb Space Telescope, astronomers found a grouping of aligned protostellar outflows within one small region (the top left corner). Serpens is a reflection nebula, which means it’s a cloud of gas and dust that does not create its own light, but instead shines by reflecting the light from stars close to or within the nebula. The discovery of these aligned objects, made possible due to Webb’s exquisite spatial resolution and sensitivity in near-infrared wavelengths, is providing information into the fundamentals of how stars are born.
      “Astronomers have long assumed that as clouds collapse to form stars, the stars will tend to spin in the same direction,” said principal investigator Klaus Pontoppidan, of NASA’s Jet Propulsion Laboratory in Pasadena, California. “However, this has not been seen so directly before. These aligned, elongated structures are a historical record of the fundamental way that stars are born.”
      So just how does the alignment of the stellar jets relate to the rotation of the star? As an interstellar gas cloud crashes in on itself to form a star, it spins more rapidly. The only way for the gas to continue moving inward is for some of the spin (known as angular momentum) to be removed. A disk of material forms around the young star to transport material down, like a whirlpool around a drain. The swirling magnetic fields in the inner disk launch some of the material into twin jets that shoot outward in opposite directions, perpendicular to the disk of material.
      In the Webb image, these jets are signified by bright clumpy streaks that appear red, which are shockwaves from the jet hitting surrounding gas and dust. Here, the red color represents the presence of molecular hydrogen and carbon monoxide.
      “This area of the Serpens Nebula – Serpens North – only comes into clear view with Webb,” said lead author Joel Green of the Space Telescope Science Institute in Baltimore. “We’re now able to catch these extremely young stars and their outflows, some of which previously appeared as just blobs or were completely invisible in optical wavelengths because of the thick dust surrounding them.”
      Astronomers say there are a few forces that potentially can shift the direction of the outflows during this period of a young star’s life. One way is when binary stars spin around each other and wobble in orientation, twisting the direction of the outflows over time.
      Stars of the Serpens
      The Serpens Nebula, located 1,300 light-years from Earth, is only one or two million years old, which is very young in cosmic terms. It’s also home to a particularly dense cluster of newly forming stars (~100,000 years old), seen at the center of this image. Some of these stars will eventually grow to the mass of our Sun.
      “Webb is a young stellar object-finding machine,” Green said. “In this field, we pick up sign posts of every single young star, down to the lowest mass stars.”
      “It’s a very complete picture we’re seeing now,” added Pontoppidan.
      So, throughout the region in this image, filaments and wisps of different hues represent reflected starlight from still-forming protostars within the cloud. In some areas, there is dust in front of that reflection, which appears here with an orange, diffuse shade.
      This region has been home to other coincidental discoveries, including the flapping “Bat Shadow,” which earned its name when 2020 data from NASA’s Hubble Space Telescope revealed a star’s planet-forming disk to flap, or shift. This feature is visible at the center of the Webb image.
      Future Studies
      The new image, and serendipitous discovery of the aligned objects, is actually just the first step in this scientific program. The team will now use Webb’s NIRSpec (Near-Infrared Spectrograph) to investigate the chemical make-up of the cloud.
      The astronomers are interested in determining how volatile chemicals survive star and planet formation. Volatiles are compounds that sublimate, or transition from a solid directly to a gas, at a relatively low temperature – including water and carbon monoxide. They’ll then compare their findings to amounts found in protoplanetary disks of similar-type stars.
      “At the most basic form, we are all made of matter that came from these volatiles. The majority of water here on Earth originated when the Sun was an infant protostar billions of years ago,” Pontoppidan said. “Looking at the abundance of these critical compounds in protostars just before their protoplanetary disks have formed could help us understand how unique the circumstances were when our own solar system formed.”
      These observations were taken as part of General Observer program 1611. The team’s initial results have been accepted in the Astrophysical Journal.
      The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing 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 CSA (Canadian Space Agency).
      Downloads
      Right click any image to save it or open a larger version in a new tab/window via the browser’s popup menu.
      View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
      Science Paper: The science paper by J. Green et al., PDF (7.93 MB) 
      Media Contacts
      Laura Betz – laura.e.betz@nasa.gov, Rob Gutro – rob.gutro@nasa.gov
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Hanna Braun hbraun@stsci.edu Christine Pulliam – cpulliam@stsci.edu
      Space Telescope Science Institute, Baltimore, Md.
      Related Information
      Animation Video – “Exploring Star and Planet Formation”
      Infographic – “Recipe for Planet Formation”
      Science Snippets Video -“Dust and the Formation of Planetary Systems“
      Interactive: Explore the jets emitted by young stars in multiple wavelengths 
      More Webb News
      More Webb Images
      Webb Mission Page
      Related For Kids
      What is the Webb Telescope?
      SpacePlace for Kids
      En Español
      Ciencia de la NASA
      NASA en español 
      Space Place para niños
      Keep Exploring Related Topics
      James Webb Space Telescope


      Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…


      Galaxies



      Stars



      Universe


      Share








      Details
      Last Updated Jun 20, 2024 Editor Stephen Sabia Contact Laura Betz laura.e.betz@nasa.gov Related Terms
      Astrophysics Goddard Space Flight Center James Webb Space Telescope (JWST) Nebulae Science & Research Star-forming Nebulae The Universe
      View the full article
    • By NASA
      6 Min Read Investigating the Origins of the Crab Nebula With NASA’s Webb
      This image by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) shows different structural details of the Crab Nebula. New data revises our view of this unusual supernova explosion.
      A team of scientists used NASA’s James Webb Space Telescope to parse the composition of the Crab Nebula, a supernova remnant located 6,500 light-years away in the constellation Taurus. With the telescope’s MIRI (Mid-Infrared Instrument) and NIRCam (Near-Infrared Camera), the team gathered data that is helping to clarify the Crab Nebula’s history.
      The Crab Nebula is the result of a core-collapse supernova from the death of a massive star. The supernova explosion itself was seen on Earth in 1054 CE and was bright enough to view during the daytime. The much fainter remnant observed today is an expanding shell of gas and dust, and outflowing wind powered by a pulsar, a rapidly spinning and highly magnetized neutron star.
      The Crab Nebula is also highly unusual. Its atypical composition and very low explosion energy previously have been explained by an electron-capture supernova — a rare type of explosion that arises from a star with a less-evolved core made of oxygen, neon, and magnesium, rather than a more typical iron core.
      “Now the Webb data widen the possible interpretations,” said Tea Temim, lead author of the study at Princeton University in New Jersey. “The composition of the gas no longer requires an electron-capture explosion, but could also be explained by a weak iron core-collapse supernova.”
      Image A: Crab Nebula (NIRCam and MIRI)
      This image by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) shows different structural details of the Crab Nebula. The supernova remnant is comprised of several different components, including doubly ionized sulfur (represented in green), warm dust (magenta), and synchrotron emission (blue). Yellow-white mottled filaments within the Crab’s interior represent areas where dust and doubly ionized sulfur coincide. The observations were taken as part of General Observer program 1714. Studying the Present to Understand the Past
      Past research efforts have calculated the total kinetic energy of the explosion based on the quantity and velocities of the present-day ejecta. Astronomers deduced that the nature of the explosion was one of relatively low energy (less than one-tenth that of a normal supernova), and the progenitor star’s mass was in the range of eight to 10 solar masses — teetering on the thin line between stars that experience a violent supernova death and those that do not.
      However, inconsistencies exist between the electron-capture supernova theory and observations of the Crab, particularly the observed rapid motion of the pulsar. In recent years, astronomers have also improved their understanding of iron core-collapse supernovae and now think that this type can also produce low-energy explosions, providing that the stellar mass is adequately low.
      Webb Measurements Reconcile Historic Results
      To lower the level of uncertainty surrounding the Crab’s progenitor star and nature of the explosion, the team led by Temim used Webb’s spectroscopic capabilities to hone in on two areas located within the Crab’s inner filaments.
      Theories predict that because of the different chemical composition of the core in an electron-capture supernova, the nickel to iron (Ni/Fe) abundance ratio should be much higher than the ratio measured in our Sun (which contains these elements from previous generations of stars). Studies in the late 1980s and early 1990s measured the Ni/Fe ratio within the Crab using optical and near-infrared data and noted a high Ni/Fe abundance ratio that seemed to favor the electron-capture supernova scenario.
      The Webb telescope, with its sensitive infrared capabilities, is now advancing Crab Nebula research. The team used MIRI’s spectroscopic abilities to measure the nickel and iron emission lines, resulting in a more reliable estimate of the Ni/Fe abundance ratio. They found that the ratio was still elevated compared to the Sun, but only modestly and much lower in comparison to prior estimates.
      The revised values are consistent with electron-capture, but do not rule out an iron core-collapse explosion from a similarly low-mass star. (Higher-energy explosions from higher-mass stars are expected to produce ratios closer to solar abundances.) Further observational and theoretical work will be needed to distinguish between these two possibilities.
      “At present, the spectral data from Webb covers two small regions of the Crab, so it’s important to study much more of the remnant and identify any spatial variations,” said Martin Laming of the Naval Research Laboratory in Washington and a co-author of the paper. “It would be interesting to see if we could identify emission lines from other elements, like cobalt or germanium.”
      Video: Crab Nebula Deconstructed

      To view this video please enable JavaScript, and consider upgrading to a web browser that
      supports HTML5 video
      This video shows the different major components that compose the Crab Nebula as observed by the James Webb Space Telescope. Despite decades of study, this supernova remnant continues to puzzle astronomers as they seek to understand what kind of progenitor star and explosion produced this dynamic environment. Image- NASA, ESA, CSA, STScI, Tea Temim (Princeton University) Video- Joseph DePasquale (STScI) Mapping the Crab’s Current State
      Besides pulling spectral data from two small regions of the Crab Nebula’s interior to measure the abundance ratio, the telescope also observed the remnant’s broader environment to understand details of the synchrotron emission and the dust distribution.
      The images and data collected by MIRI enabled the team to isolate the dust emission within the Crab and map it in high resolution for the first time. By mapping the warm dust emission with Webb, and even combining it with the Herschel Space Observatory’s data on cooler dust grains, the team created a well-rounded picture of the dust distribution: The outermost filaments contain relatively warmer dust, while cooler grains are prevalent near the center.
      “Where dust is seen in the Crab is interesting because it differs from other supernova remnants, like Cassiopeia A and Supernova 1987A,” said Nathan Smith of the Steward Observatory at the University of Arizona and a co-author of the paper. “In those objects, the dust is in the very center. In the Crab, the dust is found in the dense filaments of the outer shell. The Crab Nebula lives up to a tradition in astronomy: The nearest, brightest, and best-studied objects tend to be bizarre.”
      These findings have been accepted for publication in The Astrophysical Journal Letters.
      The observations were taken as part of General Observer program 1714.
      The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing 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 CSA (Canadian Space Agency).
      Downloads
      Right click any image to save it or open a larger version in a new tab/window via the browser’s popup menu.
      View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
      These findings have been accepted for publication in The Astrophysical Journal Letters.
      Media Contacts
      Laura Betz – laura.e.betz@nasa.gov, Rob Gutro – rob.gutro@nasa.gov
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Abigail Major – amajor@stsci.edu / Christine Pulliam – cpulliam@stsci.edu
      Space Telescope Science Institute, Baltimore, Md.
      Related Information
      Infographic: Massive Stars: Engines of Creation
      Articles: Explore Other Webb Supernova Articles
      3D visualization video : “Crab Nebula: The Multiwavelength Structure of a Pulsar Wind Nebula”
      Sonification: Multiwavelength image of the Crab Nebula
      Explore More: Crab Nebula resources from NASA’s Universe of Learning
      More Webb News
      More Webb Images
      Webb Mission Page
      Related For Kids
      What is a supernova?
      Interactive: Explore the Crab Nebula in multiple wavelengths
      Activity: Create a stellar life cycle bookmark and bracelet
      Activity: Flipbook resource for stellar evolution
      What is the Webb Telescope?
      SpacePlace for Kids
      En Español
      Qué es una  supernova?
      Ciencia de la NASA
      NASA en español 
      Space Place para niños
      Keep Exploring Related Topics
      James Webb Space Telescope


      Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…


      Galaxies



      Stars



      Universe


      Share








      Details
      Last Updated Jun 17, 2024 Editor Stephen Sabia Contact Laura Betz laura.e.betz@nasa.gov Related Terms
      Astrophysics Crab Nebula Goddard Space Flight Center James Webb Space Telescope (JWST) Nebulae Neutron Stars Pulsars Science & Research Stars Supernovae The Universe View the full article
    • By NASA
      5 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      The WL 20 group of stars is located in the Rho Ophiuchi star-forming region, imaged here by NASA’s now-retired Spitzer Space Telescope. Located near the constellations Scorpius and Ophiuchus, the region is about 407 light-years from Earth. NASA/JPL-Caltech Managed by NASA’s Jet Propulsion Laboratory through launch, Webb’s Mid-Infrared Instrument also revealed jets of gas flowing into space from the twin stars.
      Scientists recently got a big surprise from NASA’s James Webb Space Telescope when they turned the observatory toward a group of young stars called WL 20. The region has been studied since the 1970s with at least five telescopes, but it took Webb’s unprecedented resolution and specialized instruments to reveal that what researchers long thought was one of the stars, WL 20S, is actually a pair that formed about 2 million to 4 million years ago.
      The discovery was made using Webb’s Mid-Infrared Instrument (MIRI) and was presented at the 244th meeting of the American Astronomical Society on June 12. MIRI also found that the twins have matching jets of gas streaming into space from their north and south poles.
      “Our jaws dropped,” said astronomer Mary Barsony, lead author of a new paper describing the results. “After studying this source for decades, we thought we knew it pretty well. But without MIRI we would not have known this was two stars or that these jets existed. That’s really astonishing. It’s like having brand new eyes.”
      This artist’s concept shows two young stars nearing the end of their formation. Encircling the stars are disks of leftover gas and dust from which planets may form. Jets of gas shoot away from the stars’ north and south poles. The team got another surprise when additional observations by the Atacama Large Millimeter/submillimeter Array (ALMA), a group of more than 60 radio antennas in Chile, revealed that disks of dust and gas encircle both stars. Based on the stars’ age, it’s possible that planets are forming in those disks.
      The combined results indicate that the twin stars are nearing the end of this early period of their lives, which means scientists will have the opportunity to learn more about how the stars transition from youth into adulthood.
      “The power of these two telescopes together is really incredible,” said Mike Ressler, project scientist for MIRI at NASA’s Jet Propulsion Laboratory and co-author of the new study. “If we hadn’t seen that these were two stars, the ALMA results might have just looked like a single disk with a gap in the middle. Instead, we have new data about two stars that are clearly at a critical point in their lives, when the processes that formed them are petering out.”
      This image of the WL 20 star group combines data from the Atacama Large Millimeter/submillimeter Array and the Mid-Infrared Instrument on NASA’s Webb telescope. Gas jets emanating from the poles of twin stars appear blue and green; disks of dust and gas surrounding the stars are pink.U.S. NSF; NSF NRAO; ALMA; NASA/JPL-Caltech; B. Saxton Stellar Jets
      WL 20 resides in a much larger, well-studied star-forming region of the Milky Way galaxy called Rho Ophiuchi, a massive cloud of gas and dust about 400 light-years from Earth. In fact, WL 20 is hidden behind thick clouds of gas and dust that block most of the visible light (wavelengths that the human eye can detect) from the stars there. Webb detects slightly longer wavelengths, called infrared, that can pass through those layers. MIRI detects the longest infrared wavelengths of any instrument on Webb and is thus well equipped for peering into obscured star-forming regions like WL 20.
      Radio waves can often penetrate dust as well, though they may not reveal the same features as infrared light. The disks of gas and dust surrounding the two stars in WL 20S emit light in a range that astronomers call submillimeter; these, too, penetrate the surrounding gas clouds and were observed by ALMA.
      These four images show the WL 20 star system as seen by (from left) NASA’s Infrared Telescope Facility at the Mauna Kea Observatory, the Hale 5.0-meter telescope the Palomar Observatory, the Keck II telescope, and the NASA’s Webb telescope and the Atacama Large Millimeter/submillimeter Array. But scientists could easily have interpreted those observations as evidence of a single disk with a gap in it had MIRI not also observed the two stellar jets. The jets of gas are composed of ions, or individual atoms with some electrons stripped away that radiate in mid-infrared wavelengths but not at submillimeter wavelengths. Only an infrared instrument with spatial and spectral resolution like MIRI’s could see them.
      ALMA can also observe clouds of leftover formation material around young stars. Composed of whole molecules, like carbon monoxide, these clouds of gas and dust radiate light at these longer wavelengths. The absence of those clouds in the ALMA observations shows that the stars are beyond their initial formation phase.
      “It’s amazing that this region still has so much to teach us about the life cycle of stars,” said Ressler. “I’m thrilled to see what else Webb will reveal.”
      More About the Mission
      The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing 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 CSA (Canadian Space Agency).
      MIRI was developed through a 50-50 partnership between NASA and ESA. A division of Caltech in Pasadena, California, JPL led the U.S. efforts for MIRI, and a multinational consortium of European astronomical institutes contributes for ESA. George Rieke with the University of Arizona is the MIRI science team lead. Gillian Wright is the MIRI European principal investigator.
      The MIRI cryocooler development was led and managed by JPL, in collaboration with Northrop Grumman in Redondo Beach, California, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
      News Media Contact
      Calla Cofield
      Jet Propulsion Laboratory, Pasadena, Calif.
      626-808-2469
      calla.e.cofield@jpl.nasa.gov
      2024-085
      Share
      Details
      Last Updated Jun 13, 2024 Related Terms
      James Webb Space Telescope (JWST) Astrophysics Exoplanets Jet Propulsion Laboratory Stars Explore More
      5 min read NASA’s Perseverance Fords an Ancient River to Reach Science Target
      Article 3 hours ago 4 min read Coming in Hot — NASA’s Chandra Checks Habitability of Exoplanets
      Article 1 day ago 6 min read NASA’s Roman Mission Gets Cosmic ‘Sneak Peek’ From Supercomputers
      Article 1 day ago Keep Exploring Discover Related Topics
      Missions
      Humans in Space
      Climate Change
      Solar System
      View the full article
    • By NASA
      6 Min Read NASA’s Webb Opens New Window on Supernova Science
      The JADES Deep Field uses observations taken by NASA’s James Webb Space Telescope (JWST) as part of the JADES (JWST Advanced Deep Extragalactic Survey) program. A team of astronomers studying JADES data identified about 80 objects that changed in brightness over time. Most of these objects, known as transients, are the result of exploding stars or supernovae. See annotated image below. Peering deeply into the cosmos, NASA’s James Webb Space Telescope is giving scientists their first detailed glimpse of supernovae from a time when our universe was just a small fraction of its current age. A team using Webb data has identified 10 times more supernovae in the early universe than were previously known. A few of the newfound exploding stars are the most distant examples of their type, including those used to measure the universe’s expansion rate.
      “Webb is a supernova discovery machine,” said Christa DeCoursey, a third-year graduate student at the Steward Observatory and the University of Arizona in Tucson. “The sheer number of detections plus the great distances to these supernovae are the two most exciting outcomes from our survey.”
      DeCoursey presented these findings in a press conference at the 244th meeting of the American Astronomical Society in Madison, Wisconsin.
      Image A: Jades Deep Field Annotated
      The JADES Deep Field uses observations taken by NASA’s James Webb Space Telescope (JWST) as part of the JADES (JWST Advanced Deep Extragalactic Survey) program. A team of astronomers studying JADES data identified about 80 objects (circled in green) that changed in brightness over time. Most of these objects, known as transients, are the result of exploding stars or supernovae. Prior to this survey, only a handful of supernovae had been found above a redshift of 2, which corresponds to when the universe was only 3.3 billion years old — just 25% of its current age. The JADES sample contains many supernovae that exploded even further in the past, when the universe was less than 2 billion years old. It includes the farthest one ever spectroscopically confirmed, at a redshift of 3.6. Its progenitor star exploded when the universe was only 1.8 billion years old.
      ‘A Supernova Discovery Machine’
      To make these discoveries, the team analyzed imaging data obtained as part of the JWST Advanced Deep Extragalactic Survey (JADES) program. Webb is ideal for finding extremely distant supernovae because their light is stretched into longer wavelengths — a phenomenon known as cosmological redshift.
      Prior to Webb’s launch, only a handful of supernovae had been found above a redshift of 2, which corresponds to when the universe was only 3.3 billion years old — just 25% of its current age. The JADES sample contains many supernovae that exploded even further in the past, when the universe was less than 2 billion years old.
      Previously, researchers used NASA’s Hubble Space Telescope to view supernovae from when the universe was in the “young adult” stage. With JADES, scientists are seeing supernovae when the universe was in its “teens” or “pre-teens.” In the future, they hope to look back to the “toddler” or “infant” phase of the universe.
      To discover the supernovae, the team compared multiple images taken up to one year apart and looked for sources that disappeared or appeared in those images. These objects that vary in observed brightness over time are called transients, and supernovae are a type of transient. In all, the JADES Transient Survey Sample team uncovered about 80 supernovae in a patch of sky only about the thickness of a grain of rice held at arm’s length.
      “This is really our first sample of what the high-redshift universe looks like for transient science,” said teammate Justin Pierel, a NASA Einstein Fellow at the Space Telescope Science Institute (STScI) in Baltimore, Maryland. “We are trying to identify whether distant supernovae are fundamentally different from or very much like what we see in the nearby universe.”
      Pierel and other STScI researchers provided expert analysis to determine which transients were actually supernovae and which were not, because often they looked very similar.
      The team identified a number of high-redshift supernovae, including the farthest one ever spectroscopically confirmed, at a redshift of 3.6. Its progenitor star exploded when the universe was only 1.8 billion years old. It is a so-called core-collapse supernova, an explosion of a massive star. 
      Image B: Jades Deep Field Transients (NIRCam)
      This mosaic displays three of about 80 transients, or objects of changing brightness, identified in data from the JADES (JWST Advanced Deep Extragalactic Survey) program. Most of the transients are the result of exploding stars or supernovae. By comparing images taken in 2022 and 2023, astronomers could locate supernovae that recently exploded (like the examples shown in the first two columns), or supernovae that had already exploded and whose light was fading away (third column). The age of each supernova can be determined from its redshift (designated by ‘z’). The light of the most distant supernova, at a redshift of 3.8, originated when the universe was only 1.7 billion years old. A redshift of 2.845 corresponds to a time 2.3 billion years after the big bang. The closest example, at a redshift of 0.655, shows light that left its galaxy about 6 billion years ago, when the universe was just over half its current age.
      Uncovering Distant Type Ia Supernovae
      Of particular interest to astrophysicists are Type Ia supernovae. These exploding stars are so predictably bright that they are used to measure far-off cosmic distances and help scientists to calculate the universe’s expansion rate. The team identified at least one Type Ia supernova at a redshift of 2.9. The light from this explosion began traveling to us 11.5 billion years ago when the universe was just 2.3 billion years old. The previous distance record for a spectroscopically confirmed Type Ia supernova was a redshift of 1.95, when the universe was 3.4 billion years old.
      Scientists are eager to analyze Type Ia supernovae at high redshifts to see if they all have the same intrinsic brightness, regardless of distance. This is critically important, because if their brightness varies with redshift, they would not be reliable markers for measuring the expansion rate of the universe.
      Pierel analyzed this Type Ia supernova found at redshift 2.9 to determine if its intrinsic brightness was different than expected. While this is just the first such object, the results indicate no evidence that Type Ia brightness changes with redshift. More data is needed, but for now, Type Ia supernova-based theories about the universe’s expansion rate and its ultimate fate remain intact. Pierel also presented his findings at the 244th meeting of the American Astronomical Society.
      Looking Toward the Future
      The early universe was a very different place with extreme environments. Scientists expect to see ancient supernovae that come from stars that contain far fewer heavy chemical elements than stars like our Sun. Comparing these supernovae with those in the local universe will help astrophysicists understand star formation and supernova explosion mechanisms at these early times.
      “We’re essentially opening a new window on the transient universe,” said STScI Fellow Matthew Siebert, who is leading the spectroscopic analysis of the JADES supernovae. “Historically, whenever we’ve done that, we’ve found extremely exciting things — things that we didn’t expect.”
      “Because Webb is so sensitive, it’s finding supernovae and other transients almost everywhere it’s pointed,” said JADES team member Eiichi Egami, a research professor at the University of Arizona in Tucson. “This is the first significant step toward more extensive surveys of supernovae with Webb.”
      The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing 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 CSA (Canadian Space Agency). 
      Downloads
      Right click any image to save it or open a larger version in a new tab/window via the browser’s popup menu.
      View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
      Media Contacts
      Laura Betz – laura.e.betz@nasa.gov, Rob Gutro – rob.gutro@nasa.gov
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Ann Jenkins – jenkins@stsci.edu / Christine Pulliam – cpulliam@stsci.edu
      Space Telescope Science Institute, Baltimore, Md.
      Related Information
      Animation: Type 1a Supernovae Animations
      Infographic: Massive Stars: Engines of Creation
      Articles: Explore Other Supernova Articles
      More Webb News
      More Webb Images
      Webb Mission Page
      Related For Kids
      What is a supernova?
      What is the Webb Telescope?
      SpacePlace for Kids
      En Español
      Qué es una  supernova?
      Ciencia de la NASA
      NASA en español 
      Space Place para niños
      Keep Exploring Related Topics
      James Webb Space Telescope


      Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…


      Galaxies



      Stars



      Universe


      Share








      Details
      Last Updated Jun 10, 2024 Editor Stephen Sabia Contact Laura Betz laura.e.betz@nasa.gov Related Terms
      Astrophysics Galaxies Galaxies, Stars, & Black Holes James Webb Space Telescope (JWST) Missions Origin & Evolution of the Universe Science & Research The Universe View the full article
  • Check out these Videos

×
×
  • Create New...