With a new day in science comes a new study of the sun. No, we're not talking about a new telescope or a new division under the international space agencies, but rather a reallocation of a science used in other parts of space. Turning their sights from far off black holes, with a closer subject in mind, NASA's Solar Dynamics Observatory (SDO) is repositioning their NuSTAR (Nuclear Spectroscopic Telescope Array) towards our very own local star to produce the most sensitive measurements of high-energy solar x-rays to date.
While researchers have been able to observe many facets of the sun's activity with more traditional forms of technology, including several international telescopes that view the sun in different wavelengths of the visible and invisible spectra, NASA's NuSTAR marks a new age in solar research by offering astronomers the ability to view the high-energy X-ray emissions often unnoticed in a solar flare. Better known as "nanoflares", these high-energy X-ray flashes occur deep within the sun's corona, and while they may be faint, researchers with NASA hope that their high-energy emissions may reveal a better understanding of the true power of the sun.
"At first I thought the whole idea was crazy" NuSTAR principal investigator, and lead researcher of the study, Fiona Harrison said. "Why would we have the most sensitive high energy X-ray telescope ever built, designed to peer deep into the universe, look at something in our own back yard?"
But it's not such a novel idea. In fact, far before NuSTAR was even launched in 2012, solar physicists and astronomers working with NASA were petitioning that at least some of the NuSTAR mission team's time be allotted for observing things within our own solar system.
Though solar physicists have long posited that nanoflares are at fault for the coronal heating seen in the outer atmosphere in the sun, where temperatures soar beyond 1.8 million degrees Fahrenheit, their existence has proven ever illusive as researchers have never been able to fully filter out all of the noise with instrumentation used in the Solar Dynamics Observatory to date. However, with the new instrument pointed so close to home, and able to filter out the strong manetohydrodynamic waves, as well as the magnetized waves from the surface of the sun, NASA hopes to grasp a better view of the sun's dynamic behaviors and catch a glimpse of the high-energy emissions thought to heat up the sun.
"NuSTAR will give us a unique look at the sun, from the deepest to the highest parts of its atmosphere" solar physicist with the NuSTAR team, David Smith says. "NuSTAR will be exquisitely sensitive to the faintest X-ray activity happening in the solar atmosphere, and that includes possible nanoflares."