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NASA Releases First "Fully Aligned" Image From James Webb Space Telescope


Following the completion of critical mirror alignment steps, NASA’s James Webb Space Telescope team expects that Webb’s optical performance will be able to meet or exceed the science goals the observatory was built to achieve.


On March 11, the Webb team completed the stage of alignment known as “fine phasing.” At this key stage in the commissioning of Webb’s Optical Telescope Element,  every optical parameter that has been checked and tested is performing at, or above, expectations. The team also found no critical issues and no measurable contamination or blockages to Webb’s optical path. The observatory is able to successfully gather light from distant objects and deliver it to its instruments without issue.


After completing two more mirror alignment steps, we've confirmed the James Webb Space Telescope’s optical performance will be able to meet or exceed the science goals the observatory was built to achieve! Read more about this here.


While the purpose of Webb’s latest image was to focus on a bright star and evaluate the alignment progress, Webb’s optics are so sensitive that galaxies and other stars can be seen in the background. We started our alignment process with 18 scattered dots — 18 reflections of the same star, one from each of Webb’s primary mirror segments. These dots were then re-arranged, stacked, and fine-tuned by making small movements on the motors in the back of each mirror segment. This process continues to set the stage for our first science images this summer. 


While the purpose of this image was to focus on the bright star at the center for alignment evaluation, Webb's optics and NIRCam are so sensitive that the galaxies and stars seen in the background show up. At this stage of Webb’s mirror alignment, known as “fine phasing,” each of the primary mirror segments have been adjusted to produce one unified image of the same star using only the NIRCam instrument. This image of the star, which is called 2MASS J17554042+6551277, uses a red filter to optimize visual contrast.


Red is the new black (& white)! The red color palette of Webb’s image was chosen to optimize visual contrast in the image, but did you know that Hubble and Webb actually record light in black and white? They use filters that allow only a specific color of light through, then the filtered images are individually colored by scientists and image processors, and combined into a full image. Colors in space telescope imagery sometimes recreate the way our eyes see; other times they’re selected to highlight interesting features of an object, such as different elements in a nebula. (Learn more about this here.)

This new “selfie” was created using a specialized pupil imaging lens inside of the NIRCam instrument that was designed to take images of the primary mirror segments instead of images of the sky. This configuration is not used during scientific operations and is used strictly for engineering and alignment purposes. In this image, all of Webb’s 18 primary mirror segments are shown collecting light from the same star in unison.


Image Credit: NASA/STScI

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