NASA’s James Webb Space Telescope turns on the camera to observe the first star target
The spacecraft controller has begun powering four cutting-edge instruments on NASA James Webb . Space Telescope as they prepare for the observatory’s first glimpses of a target star.
That star, called HD 84406located at 241 light year from Earth and part of the constellation Ursa Major, the Great Bear. The images will not be used for science, but will help ground teams arrange 18 golden segments of Webb 21 feet (6.5 meters) wide. main mirror.
Images will be captured by Webb’s Near Infrared Camera (NIRCam), which must first cool down to an operating temperature of minus 244 degrees Fahrenheit (minus 153 degrees Celsius).
Mark McCaughrean, a scientist at the JWST Science Working Group and a senior adviser to the European Space Agency (ESA), who is familiar with the process, told Space.com: “At first, we were i will have 18 individual blurred images. “In the end, we should have a nice sharp image.”
Related: James Webb Space Telescope: The technology behind the ‘first light machine’ can’t fail
NIRCam will continue to stare at HD 84406 while Webb’s optical experts move the mirror segments in nanometer-scale steps to create a perfectly smooth surface. This work is expected to last until the end of April. Only then will individual science instruments begin to fully train their eyes for near and far objects. The universe. The first proper images are expected to be revealed to the public in late June or early July.
McCaughrean says that none of the other three can take over NIRCam’s job of helping with mirror alignment. The success of the telescope depends on the NIRCam and it simply must not be allowed to fail.
“If NIRCam fails, we won’t be able to adjust the mirror,” McCaughrean said. “That’s why it’s basically two cameras in one. There’s full redundancy. If one fails, we still have the other.”
Of the three remaining instruments, the Mid-Infrared Instrument (MIRI) was turned on partially during the telescope’s month-long journey to its destination. In the case of the other two devices – Near Infrared Spectrophotometer (NIRSPec) and Fine Guide Sensor / Near Infrared Imager and Slit-free Spectrophotometer (FGS / NIriss) – the control groups The controller now has the heater turned off to help keep warm during the cruise phase.
These heaters allow appliances to gradually release trapped air inside them and prevent water condensation and ice build-up.
It will take weeks for the devices to reach operating temperature. For MIRI, this is just 10 degrees F (5.5 degrees C) above absolute zero (minus 460 degrees F or minus 273 degrees C), the coldest possible temperature at which the motion of atoms (minus 460 degrees F or minus 273 degrees C) is possible. is the source of heat in the universe) stops. The spectrometer can operate at slightly warmer temperatures of minus 393 degrees Fahrenheit (minus 236 degrees Celsius).
This extremely low temperature is key to Webb being able to carry out its scientific tasks. Telescopes designed to record the oldest images stars and Galaxy formed in the universe during the first hundreds of millions of years Big Bang. But due to the expansion of the universe, the light emitted by these galaxies can only be seen at infrared wavelengths (the result of the so-called redshift). Since infrared light is essentially heat, the faint signal would not be noticeable if the telescope itself gave off any warmth.
While cameras like NIRCam and MIRI will produce stunning images of stars and galaxies, spectrometers will provide detailed information about the chemical composition of objects in the sky, McCaughrean explains. far there.
The James Webb Space Telescope has reached its destination, Lagrangian point 2 (L2), on January 24. L2 is a point on the Sun-Earth axis located at a distance of 930,000 miles (1.5 million km) from Earth, away from the sun. The mutual gravity of the two objects creates stable conditions at L2, making it a popular site for astronomical missions. A spacecraft at this point orbits Sun synchronized with Earth (in fact, the James Webb Space Telescope is not located directly at L2 but creates circles around it as it travels with the Earth around the sun).
James Webb . Space Telescope Released on December 25th after a decade of delay. The $10 billion mission, dreamed up by astronomers in the early 1990s, pushed the limits of what was technically possible. When its mirrors are aligned and instruments calibrated, Webb is expected to revolutionize many fields of astronomy. In addition to the first stars and galaxies, Webb will contribute to the study exoplanetsstar formation, dark matter and even the solar system and its asteroids.
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https://www.space.com/james-webb-space-telescope-turns-on-cameras NASA’s James Webb Space Telescope turns on the camera to observe the first star target
