Early results from the X-ray astronomy satellite Tenma

The observational capabilities of the Japanese Tenma X-ray satellite are described. Tenma has an array of gas scintillation proportional counters, an X-ray focusing collector, a transient source monitor, a radiation belt monitor and a gamma ray burst detector. Observations are made over the aggregate range 0.1-100 keV. Data have been taken on the X ray pulsars Vela X-1, Cen X-3, Her X-1, 1627-67 and 1538-52. A slowing of the spin-down of Vela X-1 has been noted, as was a change in the Cen X-3 period and a decrease in the period of 1538-52. The spectral curve of Vela X-1 is provided to show the Fe line ionized by X rays. Finally, 20 X ray bursts have been recorded from the sources 1636-53, 1608-52 and 1735-44. 5 references