No abstract

Eight new sources of cosmic x-rays were detected by two Aerobee surveys in 1964. One source, from Sagittarius, is close to the galactic center, and the other, from Ophiuchus, may coincide with Kepler's 1604 supernova. All the x-ray sources are fairly close to the galactic plane.

At least 30 discrete cosmic x-ray sources have been detected thus far. The distribution is concentrated toward the galactic plane, and most of the sources are believed to lie within 2 kiloparsecs of the sun. It is estimated that the average luminosity of the observed sources is about 5 x 10(36) ergs per second and that the entire galaxy contains about 1250 such sources. Comparisons of fluxes observed over the course of the past 2 years reveal that many sources are highly variable.

The x-ray flux from the Crab Nebula was observed during a lunar occultation on 7 July 1964. As the moon covered the central region of the nebula, the x-ray flux decreased gradually. The source appears to extend over a volume about 1 light-year in diameter.

Far ultraviolet emissions in the equatorial zone have been detected at altitudes of less than 500 km with an experiment aboard the Ogo 4 polar‐orbiting satellite. The occurrence frequency reached a maximum in both late October and early March during the period August 1967 to May 1968. Both maximums occurred near 2130 local time. Low values during June 1968 indicate a strong seasonal dependence. The emissions were seen quite symmetrically in position at 12°–15° on either side of the magnetic dip equator completely encircling the earth. Often, the peak intensity of the emissions was the same north and south of the equator, but in some cases the intensity was three or four times greater on one side than on the other. In rare cases, emission was totally lacking on one side while clearly present on the other. Simultaneous comparisons of ‘quick‐look’ scanning spectrometer data of Barth from Ogo 4 show that the emissions are oxygen lines at 1304 and 1356 A. Possible mechanisms for production of these emissions are discussed.