April 23, 2024

The James Webb Space Telescope: Prepare for a New Way To See the Universe

The James Webb Space Telescope (JWST) is the next of NASAs Great Observatories; following in the line of the Hubble Space Telescope, the Compton Gamma-ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope. JWST integrates the qualities of 2 of its predecessors, observing in infrared light, like Spitzer, with fine resolution, like Hubble. Credit: NASA, SkyWorks Digital, Northrop Grumman, STScI
NASAs James Webb Space Telescope is lastly prepared to do science– and its seeing the universe more plainly than even its own engineers hoped for.
NASA is arranged to launch the first images taken by the James Webb Space Telescope on July 12, 2022. Theyll mark the beginning of the next period in astronomy as Webb– the largest area telescope ever constructed– begins collecting scientific data that will assist respond to questions about the earliest minutes of the universe and permit astronomers to study exoplanets in greater information than ever previously. However it has actually taken almost 8 months of travel, setup, calibration, and screening to make sure this most valuable of telescopes is all set for prime-time television. Marcia Rieke, an astronomer at the University of Arizona and the scientist in charge of among Webbs 4 cams, discusses what she and her colleagues have been doing to get this telescope up and running.

1. Whats taken place given that the telescope introduced?
After the effective launch of the James Webb Space Telescope on December 25, 2021, the group started the long process of moving the telescope into its last orbital position, unfolding the telescope and– as everything cooled– calibrating the sensing units and cams onboard.
The launch went as efficiently as a rocket launch can go. One of the very first things my coworkers at NASA observed was that the telescope had more remaining fuel onboard than forecasted to make future changes to its orbit. This will allow Webb to run for much longer than the objectives initial 10-year goal.
The very first job during Webbs monthlong journey to its final area in orbit was to unfold the telescope. This went along with no drawbacks, beginning with the white-knuckle release of the sun shield that helps cool the telescope, followed by the positioning of the mirrors and the turning on of sensing units.
Once the sun shield was open, our group began keeping track of the temperatures of the 4 spectrometers and video cameras onboard, awaiting them to reach temperatures low enough so that we might begin testing each of the 17 various modes in which the instruments can operate.
The NIRCam, seen here, will measure infrared light from old and incredibly far-off galaxies. It was the very first instrument to go on the internet and assisted line up the 18 mirror sections. Credit: NASA/Chris Gunn
2. What did you test?
The cams on Webb cooled simply as the engineers predicted, and the first instrument the group switched on was the Near Infrared Camera– or NIRCam. NIRCam is designed to study the faint infrared light produced by the earliest stars or galaxies in deep space. However prior to it might do that, NIRCam had to assist line up the 18 individual segments of Webbs mirror.
As soon as NIRCam cooled to minus 280 F, it was cold adequate to begin finding light showing off of Webbs mirror sections and produce the telescopes very first images. When the first light image got here, the NIRCam team was overjoyed. We were in organization!
These images revealed that the mirror sections were all pointing at a fairly small location of the sky, and the alignment was far better than the worst-case circumstances we had planned for.
Webbs Fine Guidance Sensor also went into operation at this time. This sensor assists keep the telescope pointing steadily at a target– just like image stabilization in customer digital electronic cameras. Using the star HD84800 as a referral point, my coworkers on the NIRCam group helped dial in the alignment of the mirror sections till it was practically best, far much better than the minimum needed for a successful mission.
3. What sensors came alive next?
As the mirror positioning finished up on March 11, the Near Infrared Spectrograph– NIRSpec– and the Near Infrared Imager and Slitless Spectrograph– NIRISS– finished cooling and joined the celebration.
NIRSpec is developed to determine the strength of various wavelengths of light originating from a target. This details can reveal the structure and temperature of far-off stars and galaxies. NIRSpec does this by looking at its target object through a slit that keeps other light out.
NIRSpec has numerous slits that permit it to look at 100 items at the same time. Staff member started by testing the numerous targets mode, commanding the slits to open and close, and they verified that the slits were responding properly to commands. Future actions will measure exactly where the slits are pointing and examine that multiple targets can be observed all at once.
NIRISS is a slitless spectrograph that will also break light into its various wavelengths, but it is much better at observing all the things in a field, not just ones on slits. It has numerous modes, including 2 that are created particularly for studying exoplanets particularly near their parent stars.
Up until now, the instrument checks and calibrations have been proceeding efficiently, and the results show that both NIRSpec and NIRISS will provide even much better data than engineers anticipated before launch.
The MIRI video camera, image on the right, permits astronomers to translucent dust clouds with incredible sharpness compared with previous telescopes like the Spitzer Space Telescope, which produced the image on the left. Credit: NASA/JPL-Caltech (left), NASA/ESA/CSA/ STScI (right).
4. What was the last instrument to turn on?
The last instrument to boot up on Webb was the Mid-Infrared Instrument, or MIRI. This sensor spots the longest wavelengths of Webbs instruments and must be kept at minus 449 F– just 11 degrees F above outright no.
Radio astronomers have actually discovered hints that there are galaxies totally hidden by dust and undetectable by telescopes like Hubble that catches wavelengths of light similar to those noticeable to the human eye. The extremely cold temperatures permit MIRI to be exceptionally conscious light in the mid-infrared variety which can pass through dust more easily. When this sensitivity is combined with Webbs big mirror, it permits MIRI to permeate these dust clouds and reveal the stars and structures in such galaxies for the first time.
5. Whats next for Webb?
As of June 15, 2022, all of Webbs instruments are on and have actually taken their first images. Furthermore, 4 imaging modes, three time series modes and 3 spectroscopic modes have been tested and licensed, leaving just three to go.
On July 12, NASA prepares to launch a suite of teaser observations that illustrate Webbs capabilities. These will show the appeal of Webb imagery and also give astronomers a real taste of the quality of data they will receive.
After July 12, the James Webb Space Telescope will start working full-time on its science mission. The detailed schedule for the coming year hasnt yet been released, but astronomers across the world are excitedly waiting to get the first information back from the most effective space telescope ever developed.
Written by Marcia Rieke, Regents Professor of Astronomy, University of Arizona.
This short article was first published in The Conversation.

The James Webb Space Telescope (JWST) is the next of NASAs Great Observatories; following in the line of the Hubble Space Telescope, the Compton Gamma-ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope. NASA is scheduled to release the very first images taken by the James Webb Space Telescope on July 12, 2022. Theyll mark the start of the next period in astronomy as Webb– the biggest area telescope ever developed– begins gathering clinical information that will help address concerns about the earliest moments of the universe and permit astronomers to study exoplanets in higher detail than ever before. Marcia Rieke, an astronomer at the University of Arizona and the scientist in charge of one of Webbs 4 electronic cameras, discusses what she and her coworkers have actually been doing to get this telescope up and running.

Once NIRCam cooled to minus 280 F, it was cold adequate to start detecting light reflecting off of Webbs mirror sectors and produce the telescopes very first images.