
AKARI (ASTRO-F) is Japan’s first infrared-ray astronomical satellite to perform "survey observation," an all-sky survey at infrared wavelengths, including those of stars and galaxies. AKARI is being designed to make this survey with greater sensitivity and higher resolution than those achieved by the Infrared Astronomy Satellite (IRAS), the world’s first astronomical satellite using infrared rays, which was launched jointly by the United Kingdom, the United States and the Netherlands in 1983.
IRAS carried an infrared telescope with a 57-cm aperture for ten months of observation. AKARI will carry a 67-cm-aperture infrared telescope, and will be capable of 550 days of observation. Observational instruments on board the AKARI are the Far-Infrared Surveyor (FIS) and the Infrared Camera (IRC) for low- to mid-range resolution spectroscopy. The low-resolution IRC is capable of continuing its observation for several years. These instruments will provide sensitivity at least ten times greater - and angular resolution several times higher - than the IRAS.
The main purpose of the ASTRO-F (AKARI) project is to understand how galaxies were formed and evolved into what we see now, how stars were born, and how planet systems were formed.
Light from stars that were born during the early evolution of the Universe can be observed at infrared wavelengths because of a cosmological Doppler effect. The most luminous phenomena in the infrared range can be those of newly-forming galaxies (protogalaxies), where large-scale star formation is taking place. AKARI will make a systematic survey of all the galaxies, which total several million, with infrared sensitivity sufficiently high to find protogalaxies.
In our own Galaxy, stars are still being born, though the number of new stars is small. AKARI will search for such newborn stars in dark clouds of dust and gas. It will investigate where and how a star forms, and how the star is structured, taking note of its mass and composition. Gas and dust around a newborn star are thought to be the seeds of planet formation. Since this gas and dust can best be observed in the infrared range, the process of planet formation will be another one of AKARI’s important assignments. AKARI is expected to return to Earth vast quantities of data that will be fundamental to today’s astronomical research: data that may detect hitherto unknown comets, allow us to monitor dying stars, and make other observations of our Solar System.
AKARI (ASTRO-F) is launched at 6:28 a.m. on February 22, 2006 (Japan Standard Time, JST) from the Uchinoura Space Center (USC) by M-V.
| International Designation Code | 2006-005A |
|---|---|
| Launch Date | 06:28, February 22, 2006 (JST) |
| Launch Vehicle | M-V-8 |
| Location | Uchinoura Space Center |
| Shape | 1.9m x 1.9m x 3.7m 5.5m (at deployment of the solar paddles) |
| Weight | Approx. 952 kg (at launch) |
| Orbiter | Circular (Sun-synchronous polar) |
| Altitude | Approx. 750 km |
| Inclination | 98.4 degrees |
| Period | 100 min |
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Japan's First Infrared Astronomy Satellite Akari (ASTRO-F)