HI-C Returns Most Detailed Images Ever of the Sun’s Corona

NASA’s High Resolution Coronal Imager (Hi-C) mission, launched Wednesday, July 11 from White Sands Missile Range in New Mexico, successfully returned (as promised!) the highest-resolution images of the Sun’s corona ever acquired. These images of the dynamic million-degree region of the Sun’s atmosphere will provide scientists with more information on the complex activity found near the Sun’s surface and how it affects space weather throughout the Solar System.

Launched aboard a 58-foot-tall (17 meter) Black Brant sounding rocket, Hi-C was equipped with exceptionally well-made mirrors — some of the finest ever made, according to the mission report. These mirrors allowed Hi-C to image a section of the Sun’s corona in extreme ultraviolet light with a resolution of 0.1 arcsec/pixel, distinguishing features as small as 135 miles (217 km) across. That’s five times the resolution of SDO images, or any previous space telescope for that matter.

That’s like the difference between watching a program on a tube television and an HD flatscreen monitor.

The image below shows the same region as seen by SDO’s AIA array and Hi-C’s innovative mirror-and-“light-maze” system:

Read: NASA to Launch the Finest Mirrors Ever Made

“These revolutionary images of the sun demonstrate the key aspects of NASA’s sounding rocket program, namely the training of the next generation of principal investigators, the development of new space technologies, and scientific advancements,” said Barbara Giles, director for NASA’s Heliophysics Division at NASA Headquarters in Washington.

During its 620-second suborbital flight, Hi-C took 165 images of a section of the Sun’s corona 135,000 miles (271,000 km) across, capturing wavelengths of light at 193 Angstroms emitted by the Sun’s super-hot 1.5 million kelvin corona. The images were focused on a large sunspot region, whose position was accurately predicted 27 days prior to launch.

“We have an exceptional instrument and launched at the right time,” said Jonathan Cirtain, senior heliophysicist at NASA’s Marshall Space Flight Center in Huntsville. “Because of the intense solar activity we’re seeing right now, we were able to clearly focus on a sizeable, active sunspot and achieve our imaging goals.”

Even though Hi-C’s flight only lasted ten minutes, of which 330 seconds were used for acquiring images, the amount of data gathered will be used by researchers for months.

“Even though this mission was only a few minutes long, it marks a big breakthrough in coronal studies,” said Leon Golub, lead investigator from the Harvard-Smithsonian Center for Astrophysics. “The Hi-C flight might be the most productive five minutes I’ve ever spent.”

Watch a 10-second video of the region shown above, seen from both Hi-C and SDO:

Read more about the Hi-C mission results here.

Image credits: NASA

NASA To Launch The Finest Mirrors Ever Made

This Wednesday NASA will launch its High Resolution Coronal Imager (HI-C) mission from White Sands Missile Range in New Mexico, sending a sounding rocket above the atmosphere with some of the best mirrors ever made to capture incredibly-detailed ultraviolet images of our Sun.

HI-C will use a state-of-the-art imaging system to focus on a region near the center of the Sun about 135,000 miles (271,000 km) across. During its brief flight — only ten minutes long — HI-C will return some of the most detailed images of the Sun’s corona ever acquired, with a resolution five times that of previous telescopes… including NASA’s Solar Dynamics Observatory.

While SDO collects images in ten wavelengths, however, HI-C will focus on just one: 193 Angstroms, a wavelength of ultraviolet radiation that best reveals the structures of the Sun’s corona present in temperatures of 1.5 million kelvin. And although HI-C’s mirrors aren’t any larger than SDO’s — about 9.5 inches in diameter — they are “some of the finest ever made.” In addition, an interior “maze” between mirrors effectively increases HI-C’s focal length.

Researchers expect HI-C’s super-smooth mirrors to resolve coronal structures as small as 100 miles (160 km) across (0.1 arcsec/pixel).

“Other instruments in space can’t resolve things that small, but they do suggest – after detailed computer analysis of the amount of light in any given pixel – that structures in the sun’s atmosphere are about 100 miles across,” said Jonathan Cirtain, project scientist for HI-C at NASA’s Marshall Space Flight Center. “And we also have theories about the shapes of structures in the atmosphere, or corona, that expect that size. HI-C will be the first chance we have to see them.”

One of the main goals of HI-C will be to place significant new constraints on theories of coronal heating and structuring, by observing the small-scale processes that exist everywhere in hot magnetized coronal plasma and establishing whether or not there are additional structures below what can currently be seen.

“This instrument could push the limits on theories of coronal heating, answering questions such as why the temperature of the sun’s corona is millions of degrees higher than that of the surface,” said Marshall’s Dr. Jonathan Cirtain, heliophysicist and principle investigator on the mission.

Read more on the NASA news release here.

Top image: A Black Brant sounding rocket containing NASA’s HI-C mission will launch on July 11, 2012 to observe the sun’s corona. (NASA) Bottom image: TRACE image of the Sun at a resolution of 0.5 arcsec/pixel. HI-C will have a resolution 5 times finer.