Astronomers using the NASA/ESA/CSA James Webb Space Telescope have delivered the most detailed images ever taken of the inner region of the Orion Nebula.
The inner region of the Orion Nebula as seen by the NIRCam instrument on board the NASA/ESA/CSA James Webb Space Telescope. This is a composite image from several filters that represents 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 the top left to the bottom right in this image, and that contains the bright star θ2 Orionis A. The scene is illuminated by a group of hot, young massive stars — known as the Trapezium Cluster — that is located just off the top right of the image. The strong and harsh ultraviolet radiation of the Trapezium cluster creates a hot, ionized environment in the upper right, and slowly erodes the Orion Bar away. Molecules and dust can survive longer in the shielded environment offered by the dense Bar, but the surge of stellar energy sculpts a region that displays an incredible richness of filaments, globules, young stars with disks and cavities. Image credit: NASA / ESA / CSA / PDRs4All ERS Team / Salomé Fuenmayor.
The Orion Nebula is a diffuse nebula located approximately 1,350 light-years away in the constellation of Orion.
Also known as NGC 1976, Messier 42, M42, LBN 974, and Sharpless 281, this glowing cloud spans about 24 light-years.
It can be seen with the naked eye as a fuzzy patch surrounding the star Theta Orionis in the Hunter’s Sword, below Orion’s belt.
The Orion Nebula had been known since the beginnings of recorded astronomy as a star, but it is so outstanding that it was first noted as an extended nebula in 1610, only a year after Galileo Galilei’s first use of the telescope.
Detailed descriptions of the nebula started appearing later in the 17th century, and it has been a popular target for anyone with a telescope ever since.
At only 2 million years old, the Orion Nebula is an ideal laboratory for studying young stars and stars that are still forming. It offers a glimpse of what might have happened when the Sun was born 4.6 billion years ago.
The new images of the nebula were obtained as part of the Early Release Science program Photodissociation Regions for All (PDRs4All) on Webb.
The inner region of as seen by the NIRCam instrument on board the NASA/ESA/CSA James Webb Space Telescope: (i) young star with disk inside its cocoon: planet forming disks of gas and dust around a young star; these disks are being photoevaporated due to the strong radiation field of the nearby stars of the Trapezium creating a cocoon of dust and gas around them; almost 180 of these externally illuminated photoevaporating disks around young stars (aka proplyds) have been discovered in the Orion Nebula, and HST-10 (the one in the picture) is one of the largest known; the orbit of Neptune is shown for comparison; (ii) filaments: the entire image is rich in filaments of different sizes and shapes; the inset shows thin, meandering filaments that are especially rich in hydrocarbon molecules and molecular hydrogen; they are believed to be created by turbulent motions of the gas within the nebula; (iii) θ2 Orionis A: the brightest star in this image is θ2 Orionis A, a star that is just bright enough to be seen with the naked eye from a dark location on Earth; stellar light that is reflecting off dust grains causes the red glow in its immediate surroundings; (iv) young star inside globule: when dense clouds of gas and dust become gravitationally unstable, they collapse into stellar embryos that gradually grow more massive until they can start nuclear fusion in their core — they start to shine; this young star is still embedded in its natal cloud. Image credit: NASA / ESA / CSA / PDRs4All ERS Team / Salomé Fuenmayor.
“We are blown away by the breathtaking images of the Orion Nebula,” said Professor Els Peeters, an astrophysicist at the University of Western Ontario.
“We started this project in 2017, so we have been waiting more than five years to get these data.”
“Observing the Orion Nebula was a challenge because it is very bright for Webb’s unprecedented sensitive instruments,” added CNRS astronomer Dr. Olivier Berné.
“But Webb is incredible, Webb can observe distant and faint galaxies, as well as Jupiter and Orion, which are some of the brightest sources in the infrared sky.”
“These new observations allow us to better understand how massive stars transform the gas and dust cloud in which they are born,” Professor Peeters said.
“Massive young stars emit large quantities of ultraviolet radiation directly into the native cloud that still surrounds them, and this changes the physical shape of the cloud as well as its chemical makeup.”
“How precisely this works, and how it affects further star and planet formation is not yet well known.”
Northern region of the Orion Nebula observed with detector A of Webb’s NIRCam instrument during observation of the Orion Bar. Can you find the frog? Image credit: NASA / ESA / CSA / PDRs4All ERS Team / Salomé Fuenmayor.
The new Webb images reveal numerous spectacular structures inside the Orion Nebula, down to scales comparable to the size of the Solar System.
“We clearly see several dense filaments. These filamentary structures may promote a new generation of stars in the deeper regions of the cloud of dust and gas. Stellar systems already in formation show up as well,” Dr. Berné said.
“Inside its cocoon, young stars with a disk of dust and gas in which planets form are observed in the nebula.”
“Small cavities dug by new stars being blown by the intense radiation and stellar winds of newborn stars are also clearly visible.”
Proplyds consist of a central protostar surrounded by a disk of dust and gas in which planets form.
Several protostellar jets, outflows and nascent stars embedded in dust are scattered throughout the images.
“We have never been able to see the intricate fine details of how interstellar matter is structured in these environments, and to figure out how planetary systems can form in the presence of this harsh radiation,” said Dr. Emilie Habart, an astronomer at the Institut d’Astrophysique Spatiale.
“These images reveal the heritage of the interstellar medium in planetary systems.”
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