James Webb’s mirror alignment continues successfully : NASA : The Tribune India

New York, February 27

The NASA space agency announced that James Webb continued on his path to becoming a Focused Observatory as the team successfully worked on the second and third of the total seven mirror alignment phases.

With the completion of these phases, called segment alignment and image stacking, the team will now begin making small adjustments to Webb’s mirror positions.

“After moving 18 scattered starlight points in Webb’s signature hexagonal formation, the team refined the image of each mirror segment by making minor adjustments, while also changing the alignment of James Webb’s secondary mirror. “, the space agency said in a statement.

Completing this process, known as segment alignment, was a key step before superimposing the light from all the mirrors so they could work in unison.

Once the segments had been aligned, the focused points reflected from each mirror were then stacked on top of each other, delivering photons of light from each segment to the same location on NIRCam’s sensor.

During this process, called Image Stacking, the team activated sets of six mirrors at a time and instructed them to repoint their light to overlap, until all points of starlight overlap.

“We still have work to do, but we’re increasingly pleased with the results we’re seeing,” said Lee Feinberg, head of optical telescope elements for Webb at NASA’s Goddard Space Flight Center.

“Years of planning and testing are paying dividends, and the team couldn’t be more excited to see what the next few weeks and months bring,” Feinberg added.

Although image stacking puts all of a star’s light in one place on NIRCam’s detector, the mirror segments still act like 18 small telescopes rather than one large one.

The segments should now be aligned to each other with an accuracy of less than the wavelength of light.

The team is now entering the fourth phase of mirror alignment, known as Coarse Phasing, where NIRCam is used to capture the light spectra of 20 separate pairs of mirror segments.

IANS

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