[▲ The star “HD 84406” taken by the Webb Space Telescope “NIRCam”. Since the 18 segments that make up the primary mirror have not been aligned, one star image is divided into 18 (Credit: NASA)].
This is the new space telescope launched on December 25, 2021.“James Webb”Near infrared camera「NIRCam（Near Infrared Camera）」This is an image obtained using.
One of the Lagrange points of the Sun and the Earth in late January 2022「L2」The Webb Space Telescope has arrived in an orbit (halo orbit) that orbits the webb space telescope, and is currently adjusting the equipment for scientific observation. The image was taken on a trial basis as part of that and was released by NASA on February 11, local time.
connection:The new space telescope “James Webb” has finally arrived at L2!To start observation this summer
It looks like there are nearly 20 stars in the image,All bright spots are the same starIs shown.The subject of the test shooting was a star regarding 260 light-years away in the direction of Ursa Major.「HD 84406」am. According to NASA, this star from Earth’s perspective was chosen because it is unmistakablely isolated from other stars, bright and easily identifiable.
[▲ Annotated image at the beginning. It shows which image was reflected on which segment (Credit: NASA)]
The reason why you can see multiple lights (near infrared rays) from one star isWebb Space Telescope StructureHas to do with.
Webb Space Telescopeprimary mirror、Secondary mirror、SunshieldEach part (a shade to block sunlight and cool the equipment) was launched in a folded state.Deploy in outer spaceThe structure is adopted. The deployment work was carried out from late December 2021 to early January 2022 and was completed successfully, but not all the work before scientific observation was completed.
[▲ Video showing from the launch of the Webb Space Telescope to the completion of the deployment of the primary mirror]
（Credit: ESA / ATG medialab）
The 6.5m diameter primary mirror of the Webb Space Telescope is18 hexagonal segmentsIt consists of.The light reflected by each segment is a single piece at the end of a long strutSecondary mirrorIt is collected in and sent from there to observation equipment such as NIRCam.
Therefore, the primary mirror“One mirror”Each segment must be precisely aligned to function as.Currently stillThe alignment of the primary mirror segment has not been completed.So, like the image at the beginning, one star image is divided into 18 pieces.
[▲ “Selfie” taken by the Webb Space Telescope. The 18 segments that make up the primary mirror are shown (Credit: NASA)]
NASA was also shot with the opening image, using a special lens built into NIRCam.Webb Space Telescope’s “Selfie”Is also open to the public. This special lens was designed to capture the primary mirror segment of the Webb Space Telescope, not for scientific observations. The image shows a primary mirror with 18 segments arranged in an orderly manner.
According to NASA, this test shot was the basis for adjusting the primary mirror. The operations team will adjust the position of the segment over the next month or so, but it is said that a lot of work remains before starting full-scale observation. The first images taken by the Webb Space Telescope in scientific observations will be released in the summer of 2022.
Source
- Image Credit: NASA
- NASA Blogs – Photons Received: Webb Sees Its First Star – 18 Times
Sentence / Takehiro Matsumura