Launched into space a month and a half ago, NASA’s James Webb Infrared Observatory transmitted to Earth the first photographs taken at the final point of its journey, at a distance of about 1.5 million kilometers from our planet.
However, those who expect to see stunning pictures of distant galaxies in the pictures taken by astronomers – like those photographed by Hubble – will be disappointed. The first images from the James Webb’s main camera are neither bright nor clear nor varied.
Strictly speaking, the resulting image is composed of more than 1,000 individual photographs of the same star – HD 84406, located at a distance of only about 260 light-years, in the constellation Ursa Major, and in characteristics very similar to our Sun.
It is impossible to see it from Earth with the naked eye. But if you have powerful binoculars (or any telescope – even a child’s telescope will do), finding HD 84406 in the night sky is not difficult. You just need to find the Ursa Big Dipper known to any schoolchild and look a little to the right.
The first bright star on the imaginary line passing through the upper “edge” of the bucket will be the desired yellow dwarf.
Out of focus
However, if you look at a picture combined from hundreds of images, you can be surprised to find that not one, but a whole scattering of stars stands out there – a good one and a half dozen.
In fact, there are exactly 18 bright points – according to the number of segments of the main James Webb mirror, each of which now actually works as a separate mirror. So in fact, the picture shows not different stars, but 18 “versions” of the same one.
The light emanating from it just hit different places on the infrared camera lens, reflected from different surfaces.
This can be seen most clearly in the “selfie” sent by the telescope. In the very center of the image, where the James Webb secondary mirror is located, if you look closely, you can see the outlines of the same star pattern.
This is exactly what was intended, and at NASA these (unremarkable for the layman) blurry pictures were eagerly waiting for the applicant on the eve of the enrollment order – in order to quickly start the main work.
Now the engineers need to change the slope of each of the reflective segments, fitting them together in such a way that all 18 points converge into one, folded into a single gigantic gilded dish.
It will take about a month for the telescope to complete this most complex space choreography.
Scientists hope that James Webb, which cost NASA an astronomical sum of $10 billion, will provide a glimpse into the past, at the time of the formation of the universe and galaxies.
This is possible because the telescope is able to pick up signals from stars as far away as 13.5 billion light-years away. That is, he will be able to look at the Universe as it looked just 200 million years after the Big Bang.
The BBC Russian Service spoke in detail about how the telescope will work and what revolutionary discoveries can be made with it on the eve of the launch of the mission.
