Lagoon Nebula (Infrared-light View)

Hubble 28th Anniversary Image in Infrared Shows Promise of Webb Telescope

This star-filled image, taken by NASA’s Hubble Space Telescope in near-infrared wavelengths of light, reveals a very different view of the Lagoon Nebula compared to its visible-light portrait. Making infrared observations of the cosmos allows astronomers to penetrate vast clouds of gas and dust to uncover hidden gems. Hubble’s view offers a sneak peek at the dramatic vistas NASA’s James Webb Space Telescope will provide.

The most obvious difference between Hubble’s infrared and visible photos of this region is the abundance of stars that fill the infrared field of view. Most of them are more distant, background stars located behind the nebula itself. However, some of these pinpricks of light are young stars within the Lagoon Nebula. The brilliant star near the center of the frame, known as Herschel 36, is about 200,000 times brighter than our Sun.

This hefty star is 32 times more massive and eight times hotter than our Sun. Its powerful ultraviolet radiation and fierce stellar winds are carving away the surrounding nebula, removing the raw materials that smaller stars need to form. Dark smudges known as Bok globules mark the thickest parts of the nebula, where dust protects still-forming stars and their planets. While Hubble cannot penetrate these dusty clumps, Webb will be able to see through them.

Webb will probe young stars still in the process of forming. It also will examine the disks of dust and gas surrounding those stars, known as protoplanetary disks, in order to determine how far the planet formation process has proceeded. Webb will determine whether the inner regions of those disks have been cleared out, the dust either swept up by protoplanets or swept away by stellar winds.

Webb could take a stellar census of the Lagoon Nebula to determine not only how many massive stars it contains, but also how many Sun-like stars and how many failed stars known as brown dwarfs. This would enable astronomers to get the big picture of the stellar population across the entire range of masses, particularly at the low end.

The image shows a region of the nebula measuring about 4 light-years across. The observations were taken by Hubble’s Wide Field Camera 3 between Feb. 12 and Feb. 18, 2018.