Akari (ASTRO-F) is an infrared astronomy satellite developed by Japan Aerospace Exploration Agency, in cooperation with institutes of Europe and Korea. It was launched on 21 February 2006, at 21:28 UTC (06:28, 22 February JST) by M-V rocket into Earth sun-synchronous orbit. After its launch it was named Akari (明かり), which means light in Japanese. Earlier on, the project was known as IRIS (InfraRed Imaging Surveyor).
|Mission type||Infrared telescope|
|Mission duration||5 years, 9 months|
|Launch mass||952 kg (2,099 lb)|
|Dimensions||5.5 m × 1.9 m × 3.2 m (18.0 ft × 6.2 ft × 10.5 ft)|
|Start of mission|
|Launch date||21:28, February 21, 2006 (UTC)|
|Launch site||M-V Pad, Uchinoura Space Center|
|End of mission|
|Deactivated||November 24, 2011|
|Semi-major axis||6,884 km (4,278 mi)|
|Perigee||423.9 km (263.4 mi)|
|Apogee||602.3 km (374.3 mi)|
|Argument of perigee||124.2012 degrees|
|Mean anomaly||354.1441 degrees|
|Mean motion||15.1995622 rev/day|
|Epoch||9 July 2015, 13:43:21 UTC|
|Diameter||0.67 m (2.2 ft)|
|Focal length||4.2 m (14 ft)|
|Wavelengths||1.7 to 180 µm (Infrared)|
|FIS: Far-Infrared Surveyor|
IRC: Infra-Red Camera
By mid-August 2006, Akari finished around 50 percent of the all sky survey.
By early November 2006, first (phase-1) all-sky survey finished. Second (phase-2) all-sky survey started on 10 November 2006.
Due to the malfunction of sun-sensor after the launch, ejection of telescope aperture lid was delayed, resulting the coolant lifespan estimate to be shortened to about 500 days from launch. However, after JAXA estimated the remaining helium during early March 2007, observation time will be extended at least until 9 September.
On 11 July 2007, JAXA informed that 90 percent of the sky was scanned twice. Also around 3,500 selected targets have been observed so far.
On 26 August 2007, liquid-Helium coolant depleted, which means the completion of far- and mid-infrared observation. More than 96 percent of the sky was scanned and more than 5,000 pointed observations were done.
During December 2007, JAXA performed orbit correction manoeuvres to bring Akari back into its ideal orbit. This was necessary because the boiled off helium led to an increase in altitude. If this would have continued energy supply would have been cut off.
In May 2011, Akari suffered a major electrical failure that rendered its science instruments inoperable when the satellite is in the Earth's shadow. The operation of satellite was terminated officially on 24 November 2011.
- Star formation over three generations in the nebula IC4954/4955 in the constellation Vulpecula.
- The first infrared detection of a supernova remnant in the Small Magellanic Cloud
- Detection of mass-loss from relatively young red-giant stars in the globular cluster NGC 104
- Detection of the molecular gas surrounding the active galactic nucleus in the ultra luminous infrared galaxy
- The constellation Orion and the winter Milky Way at 140 micrometre
- Star forming region in the constellation Cygnus
- Active star formation viewed from the outside: The peculiar spiral galaxy M101
- Dust processing in the supernova remnants in the Large Magellanic Cloud
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- "Archived copy". Archived from the original on 31 July 2007. Retrieved 12 July 2007.CS1 maint: Archived copy as title (link)
- Usui, Fumihiko; Kuroda, Daisuke; MÜLler, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; Ishihara, Daisuke; Kataza, Hirokazu; Takita, Satoshi; Oyabu, Shinki; Ueno, Munetaka; Matsuhara, Hideo; Onaka, Takashi (2011). "Asteroid Catalog Using AKARI: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. ISSN 0004-6264.
- Issei Yamamura (26 February 2008). "Happy Birthday, AKARI!". AKARI Newsletter. vol. 21. Archived from the original on 25 May 2011. Retrieved 16 May 2010.
- "赤外線天文衛星「あかり」（ASTRO-F）の運用終了について" (in Japanese). JAXA. 24 November 2011. Retrieved 24 November 2011.
- "AKARI (ASTRO-F) Results". JAXA/ISAS/LIRA. 28 November 2008. Archived from the original on 25 May 2011. Retrieved 16 May 2010.
- "新世代の赤外線天体カタログ、日本から世界に公開へ" (Press release) (in Japanese). 30 March 2010. Archived from the original on 2 April 2010. Retrieved 30 March 2010.
- "Astronomy and Astrophysics". 514. May 2010.