NASA/ESA/CSA James Webb Space Telescope has captured the sharpest infrared images of the Horsehead Nebula, one of the most iconic objects in our skies.
The images show a part of the nebula in a new light, with unprecedented spatial resolution.
The Horsehead Nebula, also known as Barnard 33, is located in the constellation Orion (The Hunter), on the western side of the Orion B molecular cloud, roughly 1300 light-years away from us.
It is a well-known photodissociation region, where ultraviolet light from young, massive stars creates a mostly neutral, warm area of gas and dust between the fully ionized gas surrounding the massive stars and the clouds in which they are born.
Thanks to Webb’s MIRI and NIRCam instruments, an international team of astronomers has revealed for the first time the small-scale structures of the illuminated edge of the Horsehead.
They have also detected a network of striated features extending perpendicular to the PDR front and containing dust particles and ionized gas entrained in the photo-evaporative flow of the nebula.
The observations have allowed astronomers to investigate the effects of dust attenuation and emission and to better understand the multidimensional shape of the nebula.
Next, astronomers intend to study the spectroscopic data that have been obtained of the nebula to evidence the evolution of the physical and chemical properties of the material observed across the nebula.
The Horsehead Nebula is considered one of the best objects in the sky to study how radiation interacts with interstellar matter. Owing to its proximity and its nearly edge-on geometry, the Horsehead Nebula is an ideal target for astronomers to study the physical structures of PDRs and the evolution of the chemical characteristics of the gas and dust within their respective environments, and the transition regions between them.
These observations were taken in the Webb GTO programme #1192 (PI: K. Misselt) and the results have been accepted for publication in Astronomy & Astrophysics (Abergel et al. 2024). Astronomers estimate that the Horsehead Nebula has about five million years left before it too disintegrates.
Journal Reference
Abergel, A., Misselt, K., Gordon, K. D., Guillard, P., Witt, A. N., Ysard, N., Baes, M., Beuther, H., Bouchet, P., Brandl, B. R., Elyajouri, M., Kannavou, O., Kendrew, S., Klassen, P., & Trahin, B. (2024). JWST observations of the Horsehead photon-dominated region I. First results from multi-band near- and mid-infrared imaging. Astronomy & Astrophysics. DOI: 10.1051/0004-6361/202449198