NuSTAR Telescope Discovers Hidden Light Shows on the Sun
In the X-ray image captured by the NuSTAR telescope, some of the hottest places in the Sun's atmosphere appeared.
The human eyes cannot perceive all the light coming from our nearest star, even on a sunny day.
NuSTAR Telescope has captured a new image that shows some part of this hidden light, including the high-energy X-rays released by the hottest material in the Sun's atmosphere.
While the observatory mainly studies objects outside our solar system, such as huge black holes and collapsed stars, it has also provided astronomers with information about our Sun.
In this composite image, NuSTAR data is shown in blue, Hinode’s XRT data is shown in green, and NASA's SDO’s AIA is represented in red.
In this image at left, wavelengths of light from three space observatories are overlapped to provide a unique view of the Sun.
In this image at right, the high-energy X-ray light detected by one of those observatories, NASA’s NuSTAR, is seen isolated; a grid was added to indicate the Sun’s surface.
The Sun appears different depending on who’s looking. From left, NASA’s NuSTAR sees high-energy X-rays; the Hinode's XRT sees lower-energy X-rays; and NASA’s SDO sees ultraviolet light.
NuSTAR’s relatively small field of view means it can’t see the entire Sun from its position in Earth orbit, so the observatory’s view of the Sun is actually a mosaic of 25 images, taken in June 2022.
The high-energy X-rays detected by NuSTAR appear at only a few locations in the Sun’s atmosphere.
By contrast, Hinode's XRT detects low-energy X-rays, and SDO's AIA detects ultraviolet light - wavelengths that are emitted across the entire face of the Sun.
NuSTAR's vision may help scientists resolve the mystery, which is one of the biggest ones surrounding our nearest star: -
"Why does the Sun’s outer atmosphere, called the corona, reach more than a million degrees – at least 100 times hotter than its surface?"
Scientists have been puzzled by this because the Sun’s heat originates in its core and travels outward. It's as if there was a fire nearby, but the air around the fire was 100 times hotter than the flames.
Nanoflares -
The source of the corona’s heat could be small eruptions in the Sun’s atmosphere called nanoflares. Flares are large outbursts of heat, light, and particles visible to a wide range of solar observatories.
NuSTAR enables physicists to investigate how frequently nanoflares occur and how they release energy. NuSTAR launched on June 13, 2012.
The observations used in these images coincided with the 12th close approach to the Sun, or perihelion, by NASA’s Parker Solar Probe, which is flying closer to our star than any other spacecraft in history.
Credits: NASA/JPL-Caltech/JAXA