The James Webb Space Telescope (Webb) has captured the most detailed and sharpest images ever of the inner region of the Orion Nebula, a stellar nursery in the constellation of Orion, 1,350 light-years from Earth.
The new images released today were targeted by an international collaboration involving researchers from Western University.
The inner region of the Orion Nebula as seen by the James Webb Space Telescope’s NIRCam instrument. This is a multi-filter composite image showing emission from ionized gas, hydrocarbons, molecular gas, dust, and scattered starlight. Most prominent is the Orion Bar, a wall of dense gas and dust that runs from upper left to lower right in this image and contains bright star θ2 Orionis A. The scene is illuminated by a cluster of hot, young, massive stars (known as the Trapezoidal Cluster) located just off the upper-right corner of the image. The strong and harsh ultraviolet radiation from the Trapezoidal Cluster creates a hot, ionized environment at the upper right and is slowly eroding the Orion Bar. Molecules and dust can survive longer in the shielded environment offered by the dense bar, but the surge of stellar energy is shaping a region that has an incredible wealth of filaments, globules, disked young stars and cavities.
Photo credits: NASA, ESA, CSA, PDRs4All ERS team; Photo editing by Salome Fuenmayor
Technical details: The image was acquired on September 11, 2022 by the James Webb Space Telescope’s NIRCam instrument. Several images with different filters were combined to create this composite image: F140M and F210M (blue); F277W, F300M, F323N, F335M and F332W (green); F405N (orange); and F444W, F480M and F470N (red).
“We are overwhelmed by the stunning images of the Orion Nebula. We started this project in 2017, so we’ve been waiting more than five years to get this data,” said western astrophysicist Els Peeters.
These images were obtained on Webb as part of the Early Release Science program Photodissociation Regions for All (PDRs4All ID 1288). Led jointly by Peeters, the French National Center for Scientific Research (CNRS) Olivier Berné and Associate Professor Emilie Habart from the Institut d’Astrophysique Spatiale (IAS), PDRs4All is an international collaboration involving a team of more than a hundred scientists in 18 countries are involved, including Western astrophysicists Jan Cami, Ameek Sidhu, Ryan Chown, Bethany Schefter, Sofia Pasquini and Baria Kahn.
Els Peeters
“These new observations allow us to better understand how massive stars alter the cloud of gas and dust in which they are born,” said Peeters, professor of western astronomy and faculty member at the Institute for Earth and Space Research.
“Massive young stars emit large amounts of ultraviolet radiation directly into the native cloud that still surrounds them, and this changes the cloud’s physical shape as well as its chemical composition. Exactly how this works and how it affects further star and planet formation is not yet known.”
The new images released today reveal numerous spectacular structures within the nebula that are comparable in size to the size of the Solar System.
Young star with disc in its cocoon: Planet forms discs of gas and dust around a young star. These discs are scattered, or “photoevaporated,” by the intense radiation field of the Trapezium’s nearby stars, creating a cocoon of dust and gas around them. Nearly 180 of these externally illuminated photoevaporating disks around young stars (aka Proplyds) have been discovered in the Orion Nebula, and HST-10 (the one pictured) is one of the largest known. Neptune’s orbit is shown for comparison.
Filaments: The whole picture is rich in filaments of different sizes and shapes. The inset here shows thin, meandering filaments particularly rich in hydrocarbon molecules and molecular hydrogen. They are believed to be caused by turbulent movement of the gas within the nebula.
θ2 Orionis A: The brightest star in this image is θ2 Orionis A, a star just bright enough to be seen with the unaided eye from a dark location on Earth. Starlight reflected off dust grains causes the red glow in its immediate vicinity.
Young star in sphere: When dense clouds of gas and dust become gravitationally unstable, they collapse into stellar embryos that gradually become more massive until they can start nuclear fusion in their cores – they start to glow. This young star is still embedded in its natal cloud.
Photo credits: NASA, ESA, CSA, PDRs4All ERS team; Photo editing by Salome Fuenmayor
Technical details: The image was acquired on September 11, 2022 by the James Webb Space Telescope’s NIRCam instrument. Several images with different filters were combined to create this composite image: F140M and F210M (blue); F277W, F300M, F323N, F335M and F332W (green); F405N (orange); and F444W, F480M and F470N (red).
“We clearly see several dense filaments. These filamentary structures could nurture a new generation of stars in the lower regions of the dust and gas cloud. Star systems that are already in formation also appear,” said Berné. “In its cocoon, young stars are observed in the nebula with a disc of dust and gas in which planets are forming. Small cavities dug by new stars blasted by the intense radiation and stellar winds of newborn stars are also clearly visible.”
Proplyds consist of a central protostar surrounded by a dust and gas disk in which planets are forming. Several dust-embedded protostellar jets, outflows, and nascent stars are scattered across the images.
“We have never been able to see the intricate fine details of how interstellar matter is structured in these environments and figure out how planetary systems can form in the presence of this harsh radiation. These images reveal the legacy of the interstellar medium in planetary systems,” Habart said.
Analog evolution
The Orion Nebula, long thought to have an environment similar to the cradle of the solar system (when it formed more than 4.5 billion years ago), is now interested in observing the Orion Nebula to use analogies to understand what happened in the first million years of our planetary evolution.
The hearts of stellar nurseries like the Orion Nebula are obscured by large amounts of stardust, making it impossible to study what’s going on inside them in visible light with telescopes like the Hubble Space Telescope. Webb detects infrared light from the cosmos, allowing observers to see through these layers of dust while revealing what’s happening deep within the nebula.
Orion Nebula: JWST versus Hubble Space Telescope (HST)
The inner region of the Orion Nebula as seen by both the Hubble Space Telescope (left) and the James Webb Space Telescope (right). The HST image is dominated by emissions from hot ionized gas, highlighting the side of Orion’s bar that faces the Trapezoidal Cluster (top right of image). The JWST image also shows the cooler molecular material a little farther from the Trapezoidal Cluster (e.g. compare the position of Orion’s bar relative to bright star θ2 Orionis A). Webb’s sensitive infrared vision can also see through thick layers of dust and spot fainter stars, allowing scientists to study what’s going on deep inside the nebula.
Photo credits: NASA, ESA, CSA, PDRs4All ERS team; Photo editing by Olivier Berné.
HST image source: NASA/STScI/Rice Univ./C.O’Dell et al. – Program ID: PRC95-45a. Technical details: The HST image uses WFPC2 mosaic. This composite image uses [OIII] (blue), ionized hydrogen (green) and [NII] (red).
“Observing the Orion Nebula was challenging because it is very bright for Webb’s unprecedentedly sensitive instruments. But Webb is incredible, Webb can see distant and faint galaxies, as well as Jupiter and Orion, which are some of the brightest sources in the infrared sky,” Berné said.
At the heart of the Orion Nebula is the “Trapezoid Cluster” of young massive stars, whose intense ultraviolet radiation shapes the cloud of dust and gas. Understanding how this intense radiation affects its surroundings is a key question in understanding the formation of star systems like our own solar system.
“Seeing these first images of the Orion Nebula is just the beginning. The PDRs4All team is hard at work analyzing the Orion data, and we await new discoveries about these early stages of stellar system formation,” Habart said. “We are excited to be part of Webb’s journey of discovery.”
Webb is the most powerful space telescope in human history. Developed in collaboration with NASA, the European Space Agency and the Canadian Space Agency (CSA), it features an iconic 6.5 meter wide mirror composed of a honeycomb pattern of 18 hexagonal, gold-coated mirror segments and a pentagonal layer, diamond-shaped Sun protection the size of a tennis court. As a partner, CSA will receive a guaranteed share of Webb’s observing time, allowing Canadian scientists to be among the first to examine data collected by the most advanced space telescope ever.
Orion Nebula: JWST versus the Spitzer Space Telescope
The inner region of the Orion Nebula as seen by both the Spitzer Space Telescope (left) and the James Webb Space Telescope (right). Both images were taken with a filter that is particularly sensitive to the emission of hydrocarbon dust, which illuminates the entire image. This comparison is a powerful illustration of how incredibly sharp Webb’s images are compared to its infrared precursor, the Spitzer Space Telescope. This is immediately apparent from the intricate filaments, but Webb’s keen eyesight also allows us to better distinguish stars from globules and protoplanetary disks.
Photo credits: NASA, ESA, CSA, PDRs4All ERS team; Photo editing by Olivier Berné.
Credit for the Spitzer image: NASA/JPL-Caltech/T. Megaath (University of Toledo, Ohio)
Technical Details: The Spitzer image shows infrared light at 3.6 microns captured by Spitzer’s Infrared Array Camera (IRAC). The JWST image shows infrared light at 3.35 microns captured by JWST NIRCam. Black pixels are artifacts due to saturation of the detectors by bright stars.
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