Nuove immagini Web rivelano una vista straordinaria della Nebulosa di Orione
“We are blown away by the breathtaking images of the Orion Nebula. We started this project in 2017, so we have been waiting more than five years to get these data,” said Western University astrophysicist Els Peeters.
These images have been obtained as part of the Early Release Science program Photodissociation Regions for All (PDRs4All ID 1288) on JWST. Co-led by Peeters, French National Centre for Scientific Research (CNRS) scientist Olivier Berné, and Institut d’Astrophysique Spatiale (IAS) associate professor Emilie Habart, PDRs4All is an international collaboration that involves a team of more than one hundred scientists in 18 countries. Other Western University astrophysicists involved in PDRs4All include Jan Cami, Ameek Sidhu, Ryan Chown, Bethany Schefter, Sofia Pasquini, and Baria Kahn.
“These new observations allow us to better understand how massive stars transform the gas and dust cloud in which they are born,” said Peeters. She is a Western University astronomy professor and faculty member at the Institute for Earth and Space Exploration.
“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.”
The newly released images reveal numerous spectacular structures inside the 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,” said Berné. “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, or ionized protoplanetary disks, consist of a central protostar surrounded by a disk of dust and gas in which planets form. Scattered throughout the images are several protostellar jets, outflows, and nascent stars embedded in dust.
“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. These images reveal the heritage of the interstellar medium in planetary systems,” said Habart.
Evoluzione analogica
La Nebulosa di Orione è stata a lungo considerata un ambiente simile alla Culla del Sistema Solare (quando si formò oltre 4,5 miliardi di anni fa). Questo è il motivo per cui gli scienziati oggi sono interessati all’osservazione della Nebulosa di Orione. Sperano di capire, per analogia, cosa è successo durante il primo milione di anni dell’evoluzione del nostro pianeta.
Poiché i nuclei dei vivai stellari come la Nebulosa di Orione sono oscurati da grandi quantità di polvere di stelle, rende impossibile studiare cosa accade al loro interno nella luce visibile con telescopi come Telescopio spaziale Hubble. Webb rileva un file luce infrarossa dal cosmo, consentendo agli astronomi di vedere questi strati di polvere e rilevare il movimento che si verifica nelle profondità della nebulosa.
“Osservare la Nebulosa di Orione è stata una sfida perché è troppo luminosa per i dispositivi di Webb senza precedenti. Ma Webb è incredibile, Webb può anche osservare galassie lontane e deboli”.[{” attribute=””>Jupiter and Orion, which are some of the brightest sources in the infrared sky,” said Berné.
At the heart of the Orion Nebula is the ‘trapezium cluster’ (also known as Theta Orionis), which was discovered by Galileo. It contains young massive stars whose intense ultraviolet radiation shapes the cloud of dust and gas. Understanding how this intense radiation impacts their surroundings is a key question in understanding the formation of stellar systems like our own solar system.
“Seeing these first images of the Orion Nebula is just the beginning. The PDRs4All team is working hard to analyze the Orion data and we expect new discoveries about these early phases of the formation of stellar systems,” said Habart. “We are excited to be part of Webb’s journey of discoveries.”
Webb is the most powerful space telescope ever created in human history. It was developed in partnership with NASA, the European Space Agency, and the Canadian Space Agency (CSA), and boasts an iconic 6.5-meter-wide mirror, consisting of a honeycomb-like pattern of 18 hexagonal, gold-coated mirror segments and a five-layer, diamond-shaped sunshield the size of a tennis court. As a partner, CSA receives a guaranteed share of Webb’s observation time, making Canadian scientists some of the first to study data collected by the most advanced space telescope ever constructed.