Hinode << hih NOH day >> is a spacecraft designed to study the sun. It was launched on Sept. 22, 2006, by the Japan Aerospace Exploration Agency (abbreviated JAXA). Hinode was originally called Solar-B. JAXA officials renamed it after launch. Hinode is the Japanese word for sunrise.
One of Hinode’s major goals is to observe the formation and motion of magnetic fields produced by the sun. A magnetic field marks the influence at each point that a magnetic object exerts in the space around it. Researchers have used Hinode to study how magnetic energy is generated in solar flares. Solar flares are energy bursts associated with the sun’s magnetic field. The bursts can usually be seen in hydrogen light, X-ray, and radio wavelengths. Hydrogen light is the unique red light that comes from hydrogen. Scientists have also used Hinode to study the relationship of the sun’s magnetic field to the formation of the solar wind. The solar wind is the continuous stream of electrically charged particles that flows from the sun [see Sun (Flares); Sun (Solar wind)].
Hinode uses three instruments to observe light in the visible, ultraviolet, and X-ray wavelengths. Each of the instruments has an advantage over telescopes on previous spacecraft. The instruments have either an equal or higher resolution or a wider field of view. Resolution is a measure of an instrument’s ability to distinguish detail.
One instrument is a visible light telescope called the Solar Optical Telescope (SOT). The SOT is important for measuring small differences in the sun’s magnetic field. Hinode studies ultraviolet light using another instrument, the Extreme Ultraviolet Imaging Spectrometer (EIS). The EIS observes the corona (the outermost layer of the sun) as well as the transition region (the region below the corona). The EIS has several uses, including detecting the speed of solar particles. Finally, Hinode carries the X-ray Telescope (XRT). The XRT can image the whole sun at one time in high resolution. It can observe structures in the corona at different X-ray wavelengths using a variety of filters. The XRT became particularly valuable as solar activity began a natural cycle of increase, which occurred from 2008 to 2014. Studying light at different wavelengths gives scientists a more detailed picture of how the sun works.
Hinode orbits Earth from pole to pole. Its orbit is aligned so that the craft can see the sun continuously for months at a time. Almost every orbit, the craft returns data to a ground station in Svalbard, Norway. JAXA manages the mission from the Hinode Science Center at the National Astronomical Observatory of Japan in Tokyo. The United States centers of Hinode data research include the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, California, and the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts.
See also Corona; Space exploration (Exploring the sun); Sun (Space-based studies).
