Cosmic hourglass: Web captures image of protostar shrouded in dark clouds
Just last month, the James Webb Telescope gifted us spectacular new picture Pillars of Creation— probably the most famous image taken by Webb’s predecessor Hubble Space Telescope1995 Now the telescope is giving astronomers clues about the formation of a new star, with stunning picture of a dark, hourglass-shaped cloud surrounding the protostar, the object known as L1527.
Like us published earlierthe James Webb Space Telescope was launched in December 2021 and after a tense installation of sun shields and mirrors over several months, started taking stunning pictures. First, there he was deep field image of the Universe, published in July. After that came the pictures exoplanet atmospherethe Southern Ring Nebula, a cluster of interacting galaxies called the Stephanian Quintet, and the Carina Nebula, a star-forming region about 7,600 light-years away.
In August we received wonderful pictures Jupiter, including the auroras at both poles that result from Jupiter’s powerful magnetic field, as well as its thin rings and the gas giant’s two small moons. This followed a month later mosaic painting shows a panorama of star formation spanning an incredible 340 light-years in the Tarantula Nebula – so named for its long, dusty filaments. We were also treated to spectacular pictures Neptune and its ringswhich have not been directly observed since Voyager 2 flew by the planet in 1989 and, as already mentioned, the Pillars of Creation.
This latest image is courtesy of Webb’s primary cameraman Near infrared camera (MIRCam). To capture images of very faint objects, NIRCam’s coronagraphs block out any light coming from brighter nearby objects, much like shielding our eyes from bright sunlight helps us focus on the scene in front of us. The dark clouds of L1527 are only visible in the infrared, and NIRCam was able to capture features that were previously hidden from view. Check:
Back in 2012, astronomers used Submillimeter array—a collection of eight radio telescopes arranged in an interferometer that is also part of the Event Horizon Telescope—for study the accretion disk around L1527 and measure its properties, including its rotation. They found it the disk showed Kepler’s motion, similar to the planets in our solar system, which allowed them to determine the mass of the protostar. So learning more about L1527 could teach us more about what our Sun and solar system were like in their infancy.
Protostars are the earliest stage in stellar evolution, which typically takes about 500,000 years. The process begins when a fragment of a molecular cloud of dense dust and gas gains enough mass from the surrounding cloud to collapse under its own gravity, forming a pressure-supported core. The nascent protostar continues to attract mass onto itself, and the infalling material spirals around the center creating an accretion disk.
The protostar inside L1527 is only 100,000 years old and therefore does not generate its own energy through nuclear fusion, which turns hydrogen into helium, like a full-fledged star. Instead, its energy comes from radiation released by shock waves on the surface of the protostar and its accretion disk. Right now, it’s basically a swollen, spherical clump of gas between 20-40 percent the mass of our Sun. As the protostar continues to gain mass and further compress, its core will continue to heat up. Eventually it will become hot enough to trigger nuclear fusion and a star will be born.
The Webb image above shows how material ejected from the protostar L1527 created empty cavities above and below; the glowing orange and blue regions represent the boundaries delineating those regions. (The blue region’s color is because it has less dust, compared to the orange regions above it, which trap more blue light in dense dust so it can’t escape.) The accretion disk appears as a dark band. The image also shows filaments of molecular hydrogen, the result of impacts from the ejecting material of the protostar.
List image NASA/ESA/CSA/STScI/J. DePasquale
#Cosmic #hourglass #Web #captures #image #protostar #shrouded #dark #clouds