A ‘selfie’ acquired during Webb’s assessment on Earth(Image credit: Ball Aerospace)
Following the 2021 Christmas feast, our household was spellbound by the live broadcast, observing the heart-stopping liftoff of NASA’s $10 billion James Webb Space Observatory. Not since the 1990 launch of Hubble had telescope innovation seen such a momentous advancement.
On its voyage to deployment, Webb needed to overcome 344 conceivable weak spots. Fortunately, the launch surpassed anticipations, allowing us to finally unwind.
You may like
-
James Webb telescope captures one of the deepest-ever views of the universe — Space photo of the week
-
James Webb telescope pinpoints brightest FRB ever detected
-
Astronomers discover surprisingly lopsided disk around a nearby star using groundbreaking telescope upgrade
We intended to utilize Webb’s superior-resolution setting, technically termed the aperture masking interferometer, or simply AMI. It involves a minuscule segment of accurately engineered metal that fits inside the telescope’s cameras, refining its resolving power.
Our findings from painstakingly evaluating and optimizing AMI have now been shared on the publicly available repository arXiv as a pair of reports. We are at last able to showcase its debut triumphant observations of stars, planets, moons, and also black hole jets.
Operating an apparatus a million miles away
Hubble commenced its mission with imprecise vision — its mirror had been ground to exacting standards, yet incorrectly. By observing familiar stars and contrasting the optimal and documented visuals (much like an optometrist’s procedure), deriving a “prescription” to address this visual imperfection and constructing a compensating lens became viable.
The adjustment necessitated seven astronauts to journey aboard the Space Shuttle Endeavor in 1993 to incorporate the updated optics. Hubble orbits Earth at an altitude of just a few hundred miles, making it reachable by astronauts.
The primary mirror of the Webb telescope consists of 18 precisely ground hexagonal segments.
In contrast, Webb is positioned roughly 1 million miles away (1.5 million km) — it is unreachable for visits and repairs, compelling us to rectify challenges without any hardware modifications.
This is where AMI is essential. This constitutes the sole Australian hardware present, conceived by astronomer Peter Tuthill.
It was integrated into Webb to spot and quantify any haziness in its visuals. Even distortions in the nanometer range within Webb’s 18 hexagonal primary mirrors and numerous internal surfaces could blur the images sufficiently to impede investigations into planets or black holes, where both sensitivity and clarity are paramount.
You may like
-
James Webb telescope captures one of the deepest-ever views of the universe — Space photo of the week
-
James Webb telescope pinpoints brightest FRB ever detected
-
Astronomers discover surprisingly lopsided disk around a nearby star using groundbreaking telescope upgrade
AMI modulates the light with a deliberately patterned series of perforations in a straightforward metallic plate, greatly simplifying the identification of potential optical defects.
AMI facilitates a precise diagnostic configuration that aids in correcting any focus-related anomalies with JWST. Targeting ambiguous pixels
We sought to employ this configuration to study the nascent environments of planets, along with matter drawn towards black holes. Yet, prior to any of this, AMI indicated that Webb’s performance was not entirely optimal.
At a very delicate resolution — at the individual pixel level — all images appeared somewhat blurry due to a digital phenomenon: brighter pixels diffusing into their darker counterparts.
This is not a fault or oversight, rather an intrinsic attribute of infrared cameras that unexpectedly posed a notable problem for Webb.
This posed a substantial hurdle for observing distant planets, which are thousands of times dimmer than their host stars and situated only a few pixels away: my associates quickly established that its restrictions were more than ten times greater than projected.
Hence, we embarked on a mission to resolve it.
How we enhanced Webb’s eyesight
In a recent publication spearheaded by University of Sydney PhD candidate Louis Desdoigts, we examined stars with AMI to concurrently learn and rectify the optical and digital imperfections.
We constructed a computational replica to simulate AMI’s optical principles, accommodating variations in the contours of mirrors and apertures, as well as stellar colors.
We interfaced this with a machine learning prototype to signify the electronics utilizing an “effective detector model” — where our sole concern is its capacity to replicate data adequately, irrespective of the reason.
Following training and authentication on several test stars, this framework enabled us to compute and negate the blurring within other data, reinstating AMI to its intended function. It does not affect Webb’s actions in space, but instead rectifies the data during post-processing.
The outcome was impressive — the star HD 206893 is orbited by a diminutive planet and the most reddish-tinged brown dwarf identified (an item positioned between a star and planet). Their existence was acknowledged, but unattainable by Webb before implementing this adjustment. Now, these tiny specks distinctly emerged within our fresh maps of the system.
This remedy has cleared the path for utilizing AMI to discover undiscovered planets at previously unattainable resolutions and sensitivities.
It is effective beyond specks
Within a paired report by University of Sydney PhD student Max Charles, we extended this approach to observing beyond mere specks — even if those specks are planets — and forming intricate images at the pinnacle resolution achievable with Webb. We revisited extensively analyzed targets that challenge the telescope’s capabilities, evaluating its performance.
By utilizing this novel correction, we optimized the clarity of Jupiter’s moon Io, effectively tracking its volcanoes as it rotated throughout an hour-long duration.
As perceived by AMI, the jet originating from the black hole at the center of the galaxy NGC 1068 closely mirrored images captured by significantly larger telescopes.
Lastly, AMI is now capable of sharply delineating a dust band surrounding a pair of stars known as WR 137, a dim analog of the remarkable Apep system, aligning seamlessly with established theory.
RELATED STORIES
—’Puzzling’ object discovered by James Webb telescope may be the earliest known galaxy in the universe
—James Webb telescope may have spotted controversial ‘dark stars’ in the far universe
—The James Webb telescope proves Einstein right, 8 times over
The programming formulated for AMI serves as a prototype for considerably intricate cameras installed on Webb and its successor, the Roman space telescope. These resources necessitate optical calibration of exceptional precision, within a tiny fraction of a nanometer — surpassing the capacity of existing materials.
Our findings highlight that by gauging, regulating, and adjusting the materials currently at our disposal, we can still aspire to locate Earth-like planets in the distant regions of our galaxy.
This modified article has been republished from The Conversation under a Creative Commons license. Review the original publication.
TOPICSJames Webb Space Telescope
Benjamin PopeAssociate Professor, School of Mathematical and Physical Sciences, Macquarie University
Benjamin Pope researches planets outside of our solar system and is dedicated to formulating and implementing innovative data science methodologies for recognizing and defining their attributes. He earned his Honors and Masters degrees from the University of Sydney and studied abroad at the University of California, Berkeley, and completed his DPhil in Astrophysics at Balliol College, Oxford in 2017. He subsequently held a NASA Sagan Fellowship at New York University before joining the University of Queensland as a Lecturer, then Senior Lecturer in Astrophysics. Currently, he is serving as an associate professor at Macquarie University.
You must confirm your public display name before commenting
Please logout and then login again, you will then be prompted to enter your display name.
LogoutRead more
James Webb telescope captures one of the deepest-ever views of the universe — Space photo of the week
James Webb telescope pinpoints brightest FRB ever detected
Astronomers discover surprisingly lopsided disk around a nearby star using groundbreaking telescope upgrade
Oops! Earendel, most distant star ever discovered, may not actually be a star, James Webb Telescope reveals
I watched scientists view the interstellar comet 3I/ATLAS in real time. Here’s what they saw.
Sourse: www.livescience.com
