The James Webb Telescope just sent back these amazing images of a dying star

PURBITA SAHA / Popular Science — Thu, 23 Mar 2023 15:50:17 +0000

Wolf-Rayet stars are known to be efficient dust producers, and the Mid-Infrared Instrument (MIRI) on NASA’s James Webb Space Telescope shows this to great effect. Cooler cosmic dust glows at the longer mid-infrared wavelengths, displaying the structure of WR 124’s nebula. The nebula is made of material cast off from the aging star in random ejections, and from dust produced in the ensuing turbulence. This brilliant stage of mass loss precedes the star’s eventual supernova, when nuclear fusion in its core stops and the pressure of gravity causes it to collapse in on itself, and then explode. As MIRI demonstrates here, Webb will help astronomers to explore questions that were previously only left to theory about how much dust stars like this create before exploding in a supernova, and how much of that dust is large enough to survive the blast and go on to serve as building blocks of future stars and planets. NASA, ESA, CSA, STScI, Webb ERO Production Team

This article was originally featured on Popular Science.

In the grand scheme of the universe and its stars, our sun isn’t all that powerful or special. While its death will certainly wreak havoc on the solar system, it isn’t big enough to trigger a supernova—one of the most violent cosmic phenomena we know of.

So, to understand what a star’s demise truly entails, astronomers have to zoom around to other parts of the galaxy with tools such as GAIA and the James Webb Space Telescope (JWST). One of the fascinating subjects they’ve keyed in on is WR 124, a “runaway star” that’s speeding away from home as it sheds gas, dust, and other stellar matter. Located at a distance of 15,000 light-years from Earth, it’s churning through a pre-supernova state that experts want to study up close.

A new JWST infrared image, captured last summer but shared publicly this week, exposes some of the explosive details scientists have been looking for. The telescope used a spectrograph and two of its advanced cameras to record the halo of dust emanating from WR 124. The star is currently in the “Wolf-Rayet phase,” in which it loses much of its mass to surrounding space. The bright white spot at the center shows the burning stellar core; the pink and purple ripples represent a nebula of hydrogen and other ejecta.

Stars of a certain magnitude will go through the Wolf-Rayet transformation as their lifespan winds down. WR 124 is one of the mightiest stars in the Milky Way, with 3,000 percent more mass than our sun. But its end is nye—it will collapse into a supernova in a few hundred thousand years.

In the meantime, astronomers will use images and other data from JWST to measure WR 124’s contribution to the universe’s “dust budget.” Dust is essential to the universe’s workings, as NASA explains. The stuff protects young stars and forms a foundation for essential molecules—and planets. But much more of it exists than we can account for, the space agency notes: “The universe is operating with a dust budget surplus.”

The spectacular cloud around WR 124 might explain why that is. “Before Webb, dust-loving astronomers simply did not have enough detailed information to explore questions of dust production in environments like WR 124, and whether the dust grains were large and bountiful enough to survive the supernova and become a significant contribution to the overall dust budget. Now those questions can be investigated with real data,” NASA shared.

As JWST enters its second year of exploration, the observatory will take a sweeping look at galaxies far and near to reconstruct a timeline of the early universe. But individual stars can add to that cosmological understanding, too, even if they aren’t all on a glorious death march like WR 124.

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17 photos of the new James Webb Space Telescope

PURBITA SAHA / Popular Science — Fri, 24 Dec 2021 16:00:00 +0000

What the James Webb Space Telescope should look like when it finally unfurls beyond the Earth's atmosphere. Adriana Manrique Gutierrez/NASA's Goddard Space Flight Center/CIL

This article originally appeared on Popular Science.

When the US, Europe, and Canada first unveiled the plans for the James Webb Space Telescope in 1997, it sounded like a pitch from an overambitious science student. The contraption would have to schlep a 26-foot-wide mirror across the solar system, while keeping its cool around the radioactive sun. But to build the Next Generation Space Telescope (as it was called at the time), astronomers had to think big. Hubble, the preeminent space telescope, needed a successor—and there were too many open questions about the Big Bang and the expanding universe.

Twenty-four years later, the Webb telescope has smashed a number of records with its design, production, and assembly. Biggest telescope built for space? Check. Costliest tool made for stargazing? Check. Dozens of delays on the way to the launch pad? Check check check.

So it’s fair to say, the stakes are higher than imagined. As the world cautiously waits for the telescope to kick off its decade-long mission (the launch date is currently set for Christmas morning), here’s a look back on what it took to prepare it for this moment.

An early concept for the James Webb Space Telescope—known at the time as the Next Generation Space Telescope—was designed by a Goddard Space Flight Center-led team. It already incorporated a segmented mirror, an “open” design, and a large deployable sunshield. In 1996, an 18-member committee led by astronomer Alan Dressler formally recommended that NASA develop a space telescope that would view the heavens in infrared light—the wavelength band that enables astronomers to see through dust and gas clouds and extends humanity’s vision farther out into space and back in time. NASA

A full-scale model of the James Webb Space Telescope debuted for the first time in 2013 at the South by Southwest festival in Austin, Texas. Chris Gunn/NASA

Ball Aerospace optical technician Scott Murray inspects the first gold primary mirror segment, a critical element of NASA’s James Webb Space Telescope, prior to cryogenic testing at the Marshall Space Flight Center in Huntsville, Alabama. David Higginbotham/NASA/MFSC

What looks like a giant golden spider weaving a web of cables and cords, is actually ground support equipment, including the Optical Telescope Simulator (OSIM), for the James Webb Space Telescope. OSIM’s job is to generate a beam of light just like the one that the real telescope optics will feed into the actual flight instruments. This photo was taken from inside a large thermal-vacuum chamber called the Space Environment Simulator (SES), at the Goddard Space Flight Center in Greenbelt, Maryland. The golden-colored thermal blankets are made of aluminized Kapton, a polymer film that remains stable over a wide range of temperatures. The structure that looks like a silver and black cube underneath the “spider” is a set of cold panels that surround OSIM’s optics. Chris Gunn/NASA

Just like drivers sometimes use snow to clean their car mirrors in winter, two Exelis Inc. engineers are practicing “snow cleaning’” on a test telescope mirror for the James Webb Space Telescope at NASA’s Goddard Space Flight Center. By shooting carbon dioxide snow at the surface, engineers are able to clean large telescope mirrors without scratching them. This technique was only used if the James Webb Space Telescope’s mirror was contaminated during integration and testing. Chris Gunn/NASA

NASA engineers inspect a new piece of technology developed for the James Webb Space Telescope, the micro shutter array, with a low light test at NASA’s Goddard Space Flight Center. Developed at Goddard to allow Webb’s Near Infrared Spectrograph to obtain spectra of more than 100 objects in the universe simultaneously, the micro shutter array uses thousands of tiny shutters to capture spectra from selected objects of interest in space and block out light from all other sources. Laura Baetz/NASA’s Goddard Space Flight Center

NASA engineer Ernie Wright looks on as the first six flight-ready James Webb Space Telescope’s primary mirror segments are prepped to begin final cryogenic testing at the Marshall Space Flight Center. This represents the first six of 18 segments that will form NASA’s James Webb Space Telescope’s primary mirror for space observations. David Higginbotham/NASA/MFSC

Contamination from organic molecules can harm delicate instruments and engineers are taking special care at NASA to prevent that from affecting the James Webb Space Telescope (and all satellites and instruments). Nithin Abraham, a thermal coatings engineer, places Molecular Adsorber Coating or “MAC” panels in the giant chamber where the Webb telescope was tested. This contamination can occur through a process when a vapor or odor is emitted by a substance. This is called “outgassing.” The “new car smell” is an example of that, and is unhealthy for people and sensitive satellite instruments. Chris Gunn/NASA

A bird’s-eye view of NASA Goddard’s cleanroom and the James Webb Space Telescope’s test backplane and mirrors sitting in their packing case. Chris Gunn/NASA

The James Webb Space Telescope emerges from Chamber A at the Johnson Space Center in Houston on December 1, 2017. The telescope’s combined science instruments and optical element exited the massive thermal vacuum testing chamber after about 100 days of cryogenic testing inside it. Scientists and engineers at Johnson put Webb through a series of tests designed to ensure the telescope functioned as expected in an extremely cold, airless environment akin to that of space. Chris Gunn/NASA

The Kapton® polymer-coated membranes of Webb’s sunshield were fully deployed and tensioned in December at Northrop Grumman in Redondo Beach, California. Northrop Grumman designed the observatory’s sunshield for NASA. During testing, engineers sent a series of commands to spacecraft hardware that activated 139 actuators, eight motors, and thousands of other components to unfold and stretch the five membranes of the sunshield into its final taut shape. A challenging part of the test is to unfold the sunshield in Earth’s gravity environment, which causes friction, unlike unfolding material in space without the effects of gravity. For launch the sunshield will be folded up around two sides of the observatory and placed in an Ariane 5 launch vehicle, which is provided by the European Space Agency. Chris Gunn/NASA

Reaching a major milestone, technicians and engineers successfully connected the two halves of the James Webb Space Telescope for the first time at Northrop Grumman’s facilities in Redondo Beach, California. To combine both halves of Webb, engineers carefully lifted the telescope (which includes the mirrors and science instruments) above the already-combined sunshield and spacecraft using a crane. Team members slowly guided the telescope into place, ensuring that all primary points of contact were perfectly aligned and seated properly. Next the team would have to electrically connect the halves, and then test the electrical connections. Chris Gunn/NASA

Technicians and engineers working to ensure the soundness of the James Webb Space Telescope by manually lower its folded sunshield layers for easier access and inspection. After being lowered, engineers thoroughly inspect all five layers of the reflective silver-colored sunshield for any issues that may have occurred as a result of acoustic testing. Acoustic testing exposes the spacecraft to similar forces and stress experienced during liftoff, allowing engineers to better prepare it for the rigors of spaceflight. Chris Gunn/NASA

The arrival of the James Webb Space Telescope to Port de Pariacabo in French Guiana on October 12, 2021. It traveled from California, through the Panama Canal, aboard the MN Colibri. 2021 ESA-CNES-Arianespace/Optique vidéo du CSG – JM Guillon

The Ariane 5 core stage is 5.4 meters in diameter and 30.5 meters high. At launch it will contain 175 tons of liquid oxygen and liquid hydrogen propellants. With its Vulcain 2 engine it provides 140 tons of thrust. It also provides roll control during the main propulsion phase. This rolling maneuver will ensure that all parts of the payload are equally exposed to the sun which will avoid overheating of any elements of the James Webb Space Telescope. Chris Gunn/NASA

The James Webb Space Telescope atop its launch vehicle, before it was encapsulated in the rocket fairing. A protective clean tent was placed around the telescope until launch time. Chris Gunn/NASA

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PURBITA SAHA / Popular Science Archives | Popular Photography

The James Webb Telescope just sent back these amazing images of a dying star

17 photos of the new James Webb Space Telescope