James Webb reveals the amazing heart of a famous nebula

This may be Webb’s finest picture since taking office.

Like all scientists, astronomers obviously have a duty to objectivity; but that doesn’t stop them from having their favorites. We can e.g. cite 30 Doradus, a galaxy particularly courted by specialists. She is excessively tall; it is one of the largest known nebulae, almost 1900 light years long! It’s also very photogenic, thanks in part to its long plumes of dust that have earned it the nickname the Tarantula Nebula.

But it is another element of this object that interests scientists today. The James Webb Space Telescope has just revealed the most interesting part, the one that had remained invisible to the eyes of all the other telescopes: the heart of this fantastic nurserywith the tens of thousands of young stars it contains.

Normally this area is hidden by a thick cloud of cosmic dust. This is an almost insurmountable obstacle for most telescopes, including good old Hubble. The latter had already captured fantastic images of the Tarantula; but his instruments, designed to capture visible light and UV, did not allow him to pierce this veil of dust.

The tarantula’s heart was finally revealed

On the other hand, it’s child’s play for James Webb’s infrared eyes. Thanks to its near-infrared Camera (NIRCam)he made a remarkable discovery: a large cavity never seen before, housed in the center of the nebula. This would have been “excavated” by overwhelming radiation coming from a large cluster of stars. These latter are visible in blue on the image of JWST.

Only the denser regions have resisted this erosion caused by the stellar winds. This material forms a kind of pillars, which are the most active areas in this nursery; it is there that the protostars are born, which will eventually emerge from their cocoon of dust to join their fellows. The researchers even surprised a star in the middle of this maturation process, which would have been completely impossible without such an exceptional tool as JWST.

One of the observatory’s other main instruments, the Mid-infrared instrument (MIRI), has also brought its stone to the building. It works at a different wavelength than the NIRCam, so it captured a very different image from the first one. Here, the goal is not to observe the heart of the nebula, but the huge cloud of dust and gas that surrounds it, in blue and purple in this image. The red and orange lights correspond to hydrocarbons, which are present in abundance in certain areas.

© NASA, ESA, CSA, STScI, Webb ERO Production Team

A unique window on “cosmic dinner

In addition to being visually stunning, these images are also full of information that scientists can tap into; it’s not every day they get to work on such precise and instructive images of one of the most fascinating objects in the cosmos.

If the Tarantula interests astronomers so much, it’s a pretty unique object. Its chemical composition, for example, are very different from those in star nurseries found in the Milky Way. On the other hand, it is surprisingly similar to the giant star factories that existed at the time of “cosmic dinner” (“cosmic dinner”). This is a crucial period in the history of our universe, when stars were produced at an alarming rate.

The Tarantula Nebula also exhibits this peculiarity; stars are born there in industrial quantities, far beyond anything observable in our cosmic backyard. Fortunately, it is also relatively close to our galaxy (just under 160,000 light years). It has therefore gradually been transformed into a large open-air laboratory where specialists can study the dynamics of the universe during this famous “cosmic dinner” under excellent conditions.

James Webb Space Telescope
©NASA

It was therefore already a fascinating object of study because the process of star formation is one of the most important elements in the dynamics of the cosmos. Understanding this phenomenon would allow scientists to make enormous advances in their overall understanding of the universe.

And it is all the more true now that James Webb has opened this scientific gift package that has been closed for ages. “The Webb has already begun to reveal a universe we’ve never seen before, and it’s only just begun to rewrite the history of star formation.“, concludes the statement from NASA.

Leave a Comment