High Resolution Coronal Imager


The High Resolution Coronal Imager is a sub-orbital telescope designed to take high-resolution images of the Sun's corona. it has been launched three times, but only the first and the third launches, on July 11, 2012, and May 29, 2018, resulted in a successful mission. It was launched aboard a Black Brant sounding rocket from White Sands Missile Range, New Mexico. The images taken were the highest resolution photos ever of the Sun's corona.

Telescope description

The telescope weighs, and is long. The mirrors are approximately across. Its optics were designed at the Marshall Space Flight Center in Huntsville, Alabama with assistance from the Smithsonian Astrophysical Observatory and L-3Com/Tinsley Laboratories of Richmond, California. Dr. Jonathan Cirtain, from MSFC said: "These mirrors were to be the finest pieces of glass ever fabricated for solar astrophysics."

Imaging system

The imaging system was designed by Apogee Imaging Systems with a resolution of 0.1 arcsec/pixel. It was based on a customized version of the E2V CCD203 from Lockheed Martin, which is a very large 4 channel back illuminated 4,000 × 4,000 pixel charge-coupled device.

Missions

The first flight lasted for 10 minutes, reached an altitude of and the telescope captured 165 images of a large active region. It imaged the Sun in ultraviolet light at 19.3 nm wavelength. The total cost of the mission was $5 million.
On the second flight, in 2018, five and a half minutes of pictures were taken of an area on the sun 4.4 arcminutes square. Seventy eight images were taken at intervals of 4.4 seconds, with a two-second exposure time, at the extreme ultraviolet wavelength of 17.2 nanometres which is dominated by Fe IX emission indicating temperatures around 800 000 Kelvin. The instrument was able to resolve strands of plasma as narrow as about 200 kilometres wide.

Findings

The first mission revealed never-before-seen "magnetic braids" of plasma roiling in the Sun's outer layers. It was the first time scientists were able to directly observe magnetic reconnection in braids, which may be the primary sources of heating in the active solar corona.