James Webb Archives

February 23, 2024February 23, 2024 by Mark Thompson

Finally! Webb Finds a Neutron Star from Supernova 1987A

I can remember seeing images of SN1987A as it developed back in 1987. It was the explosion of a star, a supernova in the Large Magellanic Cloud. Over the decades that followed, it was closely monitored in particular the expanding debris cloud. Predictions suggested there may be a neutron star or even a black hole at the core but the resolution of the telescopes was insufficient to pick anything up. Now we have the James Webb Space Telescope and using its more powerful technology, signs of a neutron star have been detected.

January 19, 2024January 19, 2024 by Mark Thompson

Early Galaxies Looked Nothing Like What We See Today

Though an estimated 100 million black holes roam among the stars in our Milky Way galaxy, astronomers have never identified an isolated black hole – until now. Following six years of meticulous observations, NASA’s Hubble Space Telescope has provided, for the first time ever, strong evidence for a lone black hole plying interstellar space. The black hole that was detected lies about 5,000 light-years away, in the Carina-Sagittarius spiral arm of our galaxy. However, its discovery allows astronomers to estimate, statistically, that the nearest isolated black hole to Earth might be as close as 80 light-years. Black holes are born from rare, monstrous stars (less than one-thousandth of the galaxy’s stellar population) that are at least 20 times more massive than our Sun. These stars explode as supernovae, and the remnant core is crushed by gravity into a black hole. Because the self-detonation is not perfectly symmetrical, the black hole may get a kick, and go careening through our galaxy like a blasted cannonball. Hubble can’t photograph the wayward black hole because it doesn’t emit any light, but instead swallows all radiation due to its intense gravitational pull. Instead, Hubble measurements capture the ghostly gravitational footprint of how the stealthy black hole warps space, which then deflects starlight from anything that momentarily lines up exactly behind it. Ground-based telescopes, which monitor the brightness of millions of stars in the rich star fields in the direction of the central bulge of our Milky Way, look for the tell-tale sudden brightening of one of them when a massive object passes between us and the star. Then Hubble follows up on the most interesting such events. Kailash Sahu of the Space Telescope Science Institute in Baltimore, Maryland, along with his team, made the discovery in a survey designed to find just such isolated black holes. The warping of space due to the gravity of a foreground object passing in front of a star located far behind it will momentarily bend and amplify the light of the background star as it passes in front of it. The phenomenon, called gravitational microlensing, is used to study stars and exoplanets in the approximately 20,000 events seen so far inside our galaxy. The signature of a foreground black hole stands out as unique among other microlensing events. The very intense gravity of the black hole will stretch out the duration of the lensing event for over 200 days. Also, If the intervening object was instead a foreground star, it would cause a transient color change in the starlight as measured because the light from the foreground and background stars would momentarily be blended together. But no color change was seen in the black hole event. Next, Hubble was used to measure the amount of deflection of the background star’s image by the black hole. Hubble is capable of the extraordinary precision needed for such measurements. The star’s image was offset from where it normally would be by two milliarcseconds. That’s equivalent to measuring the diameter of a 25-cent coin in Los Angeles as seen from New York City. This astrometric microlensing technique provided information on the mass, distance, and velocity of the black hole. The amount of deflection by the black hole’s intense warping of space allowed Sahu’s team to estimate it weighs seven solar masses. The isolated black hole is traveling across the galaxy at 90,000 miles per hour (fast enough to travel from Earth to the moon in less than three hours). That’s faster than most of the other neighboring stars in that region of our galaxy. “Astrometric microlensing in conceptually simple but observationally very tough,” said Sahu. “It is the only technique for identifying isolated black holes.” When the black hole passed in front of a background star located 28,000 light-years away in the galactic bulge, the starlight coming toward Earth was amplified for a duration of 265 days as the black hole passed by. However, it took several years of Hubble observations to follow how the background star’s position appeared to be deflected by the bending of light by the foreground black hole. The existence of stellar-mass black holes has been known since the early 1970’s, but all of them—until now—are found in binary star systems. Gas from the companion star falls into the black hole, and is heated to such high temperatures that it emits X rays. About two dozen black holes have had their masses measured in X-ray binaries through their gravitational effect on their companions. Black hole masses in X-ray binaries inside our galaxy range from 5 to 20 solar masses. Black holes detected in other galaxies by gravitational waves from mergers between black holes and companion objects have been as high as 90 solar masses. “Detections of isolated black holes will provide new insights into the population of these objects in our Milky Way,” said Sahu. He expects that his program will uncover more free-roaming black holes inside our galaxy. But it is a needle-in-a-haystack search. The prediction is that only one in 1500 microlensing events are caused by isolated black holes. NASA’s upcoming Nancy Grace Roman Space Telescope will discover several thousand microlensing events out of which many are expected to be black holes, and the deflections will be measured with very high accuracy. In a 1916 paper on general relativity, Albert Einstein predicted that his theory could be tested by observing the sun’s gravity offsetting the apparent position of a background star. This was tested by astronomer Arthur Eddington during a solar eclipse on May 29, 1919. Eddington measured a background star being offset by 2 arc seconds, validating Einstein’s theories. Both scientists could hardly have imagined that over a century later this same technique would be used – with unimaginable precision of a thousandfold better — to look for black holes across the galaxy.

Talk to anyone about galaxies and it often conjurs up images of spiral or elliptical galaxie. Thanks to a survey by the James Webb Space Telescope it seems the early Universe was full of galaxies of different shapes. In the first 6 billion years up to 80% of the galaxies were flat, surfboard like. But that’s not it, there were others like pool noodles too, yet why they looked so different back then is a mystery.

October 25, 2023October 26, 2023 by Nancy Atkinson

After DART Smashed Into Dimorphos, What Happened to the Larger Asteroid Didymos?

NASA’s DART mission (Double Asteroid Redirection Test) slammed into asteroid Dimorphos in September 2022, changing its orbital period. Ground and space-based telescopes turned to watch the event unfold, not only to study what happened to the asteroid, but also to help inform planetary defense efforts that might one day be needed to mitigate potential collisions with our planet.

Astronomers have continued to observe and study Dimorphos, well past the impact event. However, Dimorphos is the smaller asteroid in this binary system, and is just a small moon orbiting the larger asteroid Didymos.

The James Webb Space Telescope (JWST) is the only telescope capable of visually distinguishing between the two closely orbiting asteroids. Now, astronomers have made follow-on observations on the system with JWST to see what happened to Didymos after the dust cleared.

September 17, 2023September 17, 2023 by Scott Alan Johnston

A Collection of New Images Reveal X-Rays Across the Universe

NASA/CXC/SAO, JPL-Caltech, MSFC, STScI, ESA/CSA, SDSS, ESO.

One of the miracles of modern astronomy is the ability to ‘see’ wavelengths of light that human eyes can’t. Last week, astronomers put that superpower to good use and released five new images showcasing the universe in every wavelength from X-ray to infrared.

Combining data from both Earth- and ground-based telescopes, the five images reveal a diverse set of astronomical phenomena, including the galactic centre, the death throes of stars, and distant galaxies traversing the cosmos.

November 23, 2022November 23, 2022 by Matt Williams

NASA's Report Details a Dark Time in American History but Finds no Direct Evidence That Webb Fired People for Their Sexual Orientation

1963 photo showing Dr. William H. Pickering, (center) JPL Director, President John F. Kennedy, (right). NASA Administrator James Webb in background. They are discussing the Mariner program, with a model presented. Credit: NASA

NASA has announced the release of the James Webb History Report, a document detailing their investigation into the namesake of the next-generation space telescope that took to space on December 25th, 2021. Months before it launched, the observatory became the subject of controversy when it was revealed that Webb was involved in the so-called “Lavender Scare.” After reviewing the relevant documents and collections located by their historians, NASA decided not to rename its flagship observatory.

The Final Report, titled “NASA Historical Investigation into James E. Webb’s Relationship to the Lavender Scare,” was compiled by NASA Chief Historian Brian C. Odom (Ph.D., MLIS) and can be accessed through NASA’s servers.

October 27, 2022October 27, 2022 by Matt Williams

Here are Four Ways JWST Could Detect Alien Life

Artist conception of the James Webb Space Telescope. Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez

Less than a year after it went to space, the James Webb Space Telescope (JWST) has already demonstrated its worth many times over. The images it has acquired of distant galaxies, nebulae, exoplanet atmospheres, and deep fields are the most detailed and sensitive ever taken. And yet, one of the most exciting aspects of its mission is just getting started: the search for evidence of life beyond Earth. This will consist of Webb using its powerful infrared instruments to look for chemical signatures associated with life and biological processes (aka. biosignatures).

The chemical signatures vary, each representing a different pathway toward the potential discovery of life. According to The Conversation’s Joanna Barstow, a planetary scientist and an Ernest Rutherford Fellow at The Open University specializing in the study of exoplanet atmospheres, there are four ways that Webb could do this. These include looking for chemicals that lifeforms depend on, chemical byproducts produced by living organisms, chemicals essential to maintaining a stable climate, and chemicals that shouldn’t coexist.

July 15, 2022July 15, 2022 by Anton Pozdnyakov

Booster 7’s BOOM, Nuclear Mission to Neptune, More JWST Images

Even more pictures from James Webb Space Telescope, China’s planning a mission to Neptune, SpaceX’s Booster 7 suffers from an explosion, black holes are messy eaters, going under Europa’s ice crust and more.

January 29, 2022January 29, 2022 by Matt Williams

Want to Know What James Webb Looks Like in Powerful Earth Telescopes? Prepare to be Underwhelmed

The past month has been an exciting time for the James Webb Space Telescope! After launching on Christmas Day, the telescope spent the next few weeks deploying its mirrors, checking the individual segments, and then maneuvering to L2, where it will spend the next ten to twenty years unlocking the mysteries of the cosmos. According to NASA Administrator Bill Nelson, the Chief Science Communications Officer (CSCO) for the JWST and the Hubble Space Telescope (HST) for the ESA, James Webb will begin collecting light this summer.

To mark the occasion, the Virtual Telescope Project (VTP) captured images of James Webb to give people a sense of what it looks like in orbit. Unfortunately, there’s not a lot to see there, other than a bright dot in the night sky. But like Carl Sagan’s famous “Pale Blue Dot” picture of Earth (taken by Voyager 1 on its way out of the Solar System), or Cassini’s “The Day Earth Smiled” image, there’s a tremendous amount of significance in that small point of light.

December 31, 2021December 31, 2021 by Matt Williams

JWST Just Deployed a Sail That Lets it Stop Getting Pushed Around by the Sun’s Radiation.

Screenshot from NASA TV showing the Webb telescope after release from the rocket stage. Credit: NASA.

On December 25th, 2021, astronomers and space exploration enthusiasts got the greatest Christmas present of all! After years of delays, cost overruns, and additional testing, the James Webb Space Telescope (JWST) launched from Europe’s Spaceport in Kourou, French Guiana. In what was a real nail-biter, the Ariane 5 rocket and its precious payload reached orbit without a hitch. But as is so often the case, the deployment of the JWST was just the first in a series of “hurry up and wait” episodes.

Typically, periods of waiting are seeing are accompanied by plenty of worry and doubt. Luckily, there have been several positive developments since the JWST launched that could help alleviate these anxieties. The latest is how the telescope successfully deployed its aft momentum flap, an instrument that will keep the telescope oriented during its mission. The news was announced yesterday (December 30th) via @NASAWebb, NASA’s official Twitter account for the Webb telescope, and the JWST page at NASA Blogs.

December 10, 2021December 10, 2021 by Matt Williams

After 10 Days of Dangerous, Careful Work, James Webb has Been Fully Fueled up

Remplissage JWST (CU1) au S5B, le 26/11/2021. | JWST (CU1) fueling at S5B. 11/26/2021.

On Oct. 12^th, 2021, after years of waiting and cost overruns, the James Webb Space Telescope (JWST) finally arrived safely at Europe’s Spaceport in Kourou, French Guiana. The crews began unboxing the next-generation observatory and getting it ready for integration with the Ariane 5 rocket that will take it to space. Then, an “incident” occurred where a clamp band suddenly released, sending vibrations throughout the facility. Once again, the JWST’s launch date was pushed back while crews investigated the source of the problem.

But lo and behold, the due diligence is now done, and the James Webb is back on track! According to the latest news from the ESA, crews have finished fueling the JWST’s thrusters in preparation for its launch, which is scheduled for Dec. 22^nd. The Webb will use these thrusters to make course corrections after separating from the Ariane 5 rocket in orbit, maintaining its prescribed orbit, and repointing the observatory during operations.