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The TENMA (ASTRO-B) was launched on February 20, 1983, by M-3S-3 launch vehicle from Kagoshima Space Center. It aimed to observe X-ray sources from space, including X-ray stars, X-ray galaxies, gamma ray bursts, soft X-ray nebulae.

Weight: 216 kg  
Orbit : Near Circular
497 km
503 km
32 deg.
International Index: 1983-011-01  

Gas scintillation proportional counters (SPC) onboard TENMA provided a powerful tool to study cosmic X-ray sources. Their high sensitivity enabled us to trace the 283 sec pulsation from an X-ray pulsar Vela X-1 with a high data quality. Also their excellent energy resolution provided us with a high quality X-ray spectrum from this source, in which the iron K-line emission is clearly seen.

The TENMA observed a recurrent activity of the Rapid Burster in July 1984. An example of the typical type II bursts is shown here. One of the remarkable features of the type II burst is its rapid repetition with an interval of tens seconds to several minutes which is linearly proportional to the total energy emitted in the proceeding burst.


Gas scintillation proportional counter onboard TENMA has an excellent energy resolution twice as high as conventional proportional counters. X-ray energy spectrum of Cas A observed by TENMA clearly resolved complex line-features from which we can estimate the temperature and the abundance of elements in the nebula. (Right) TENMA discovered for the first time an absorption line at 4.1 keV in the spectrum of X-ray bursts from XB1636-536. This is considered to be a Fe line red-shifted from 6.4 keV due to a enormous gravity near the surface of a neutron star. (Left)

It entered the Earth atmosphere, and melted out on January 19, 1989.


On October 1, 2003, the Institute of Space and Astronautical Science (ISAS) was integrated into the Japan Aerospace Exploration Agency (JAXA) and became the Space Science Research Division of JAXA. In this reorganization, the names of organizations and facilities were changed. In this website, the names of the organizations and facilities are provided as at the time of the release of the article.

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