Media Releases

Western Space Members' Media Releases 

September 6, 2022 



Left: Hubble Space Telescope mosaic of the Orion Bar. Credit: NASA/STScI/Rice Univ./C.O’Dell et al. The NIRC2 wide camera Field of View is shown in the yellow square. Right: Infrared heat map of the Orion Bar obtained with Keck Observatory’s NIRC2 instrument reveals substructures such as proplyds. Credit: Habart et al./W. M. Keck Observatory

Astronomers using W. M. Keck Observatory on Hawaiʻi Island, including Western Space faculty member Dr. Els Peeters, have captured from Maunakea the most detailed and complete images ever taken of the zone where the famed Kaheiheionākeiki, or constellation of Orion, gets zapped with ultraviolet (UV) radiation from massive young stars. 

This irradiated neutral zone, called a Photo-Dissociation Region (PDR), is located in the Orion Bar within the Orion Nebula, an active star-forming site found in the middle of the sword” hanging from Orion’s “belt.” When viewed with the naked eye, the nebula is often mistaken for one of the stars in the constellation; when viewed with a telescope, the photogenic nebula is seen as a glowing gaseous stellar nursery located 1,350 light-years from Earth.

“It was thrilling being the first, together with my colleagues of the PDRs4AllJames Webb Space Telescope team, to see the sharpest images of the Orion Bar ever taken in the near infrared,” said Carlos Alvarez, a staff astronomer at Keck Observatory and co-author of the study.

Because the Orion Nebula is the closest massive star formation region to us and may be similar to the environment in which our solar system was born, studying its PDR – the area that’s heated by starlight - is an ideal place to find clues as to how stars and planets are created.

Peeters, a Western astronomy professor, contributed to the design of the study and cowrote the observing proposal and final paper. The study has been accepted for publication in the journal Astronomy & Astrophysics, and is available in preprint format on

These new observations from Keck Observatory have informed plans for JWST observations of the Orion Bar, which is among JWST’s targets and is expected to be observed in the coming weeks.

“Never before have we been able to observe at a small scale how interstellar matter structures depend on their environments, particularly how planetary systems could form in environments strongly irradiated by massive stars,” said Habart. “This may allow us to better understand the heritage of the interstellar medium in planetary systems, namely our origins.”

Massive young stars emit large quantities of UV radiation that affect the physics and chemistry of their local environment; how this surge of energy the stars inject into their native cloud impacts and shapes star formation is not yet well known.

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