41. They lie off the galactic plane in the Gould Belt, a region filled with gas clouds and massive stars. 42. The orbital inclination is at an angle of from the galactic plane , carrying it as much as above the disk. 43. If the sources were from within our own galaxy they would be strongly concentrated in or near the galactic plane . 44. The remaining areas to search are near aphelion, which is located close to the galactic plane of the Milky Way. 45. Oort proposed the substance after measuring the motions of nearby stars in the Milky Way relative to the galactic plane . 46. This star lies about 5?from the galactic plane and about 30?from the line of sight to the Galactic Center. 47. Its thickness is about 10 times that of the rest of the galaxy, extending well above and below the galactic plane . 48. It reaches a peak distance above the galactic plane of and will cross the plane with a period of 31.7 Ma. 49. He found that the mass of the galactic plane must be more than the mass of the material that can be seen. 50. Of the 170 yet-unidentified stable gamma ray sources in the galaxy, about half lie in a narrow band along the galactic plane .
