X-Ray Sources
Abstract
F. Makino and the Ginga Team, Institute of Space and Astronautical Science, Sagamihara, Kanagawa, report: "A bright x-ray nova has been detected at R.A. = 20h01.6m, Decl. = +24.9 deg (equinox 1950.0, uncertainty +/- 0.3 deg). It was observed on Apr. 26.04 UT with the all-sky monitor on Ginga at an intensity of a few times that of the Crab Nebula. The intensity on Apr. 27.17 UT was approximately 1.2 x 10**-7 erg cm**-2 s**-1, or about 6 Crab, in the energy range 2-7 keV. The spectrum is very soft, and kT = 2 keV for a thin thermal emission. Since discovery the daily rate of energy increase has been less than 10 percent, suggesting that the object is near maximum. The source was not detectable (intensity less than 0.05 Crab) on Apr. 22.17 UT." They also communicate: "The transient x-ray source reported on IAUC 4583 has been found to be an x-ray pulsar. The heliocentric pulsation period is determined as 29.508 +/- 0.002 s. The pulse profile is roughly sinusoidal with a small modulation of about 10 percent (peak-to-peak). There are also chaotic variations superimposed on the regular pulses."
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- April 1988
- Bibcode:
- 1988IAUC.4587....1M