NGC 6559: 礁湖星云东侧的天体

NGC 6559: 礁湖星云东侧的天体

2021年10月7日 NGC 6559: East of the Lagoon Image Credit & Copyright: Roberto Sartori Explanation: Slide your telescope just east of the Lagoon Nebula to find this alluring field of view in the rich starfields of the constellation Sagittarius toward the central Milky Way. Of course the Lagoon nebula is also known as M8, the eighth object listed in Charles Messier’s famous catalog of bright nebulae and star clusters. Close on the sky but slightly fainter than M8, this complex of nebulae was left out of Messier’s list though. It contains obscuring dust, striking red emission and blue reflection nebulae of star-forming region NGC 6559 at right. Like M8, NGC 6559 is located about 5,000 light-years away along the edge of a large molecular cloud. At…

NGC 1499:加州星云

NGC 1499:加州星云

2019 August 23 NGC 1499: The California Nebula Image Credit & Copyright: Sara Wager Explanation: Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun also lies within the Milky Way’s Orion Arm, only about 1,500 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. The California Nebula shines with the telltale reddish glow characteristic of hydrogen atoms recombining with long lost electrons. The electrons have been stripped away, ionized by energetic starlight. Most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish star Xi…

邻近的旋涡星系NGC 4945

邻近的旋涡星系NGC 4945

2019 August 22 Nearby Spiral Galaxy NGC 4945 Image Credit & Copyright: Martin Pugh Explanation: Large spiral galaxy NGC 4945 is seen edge-on near the center of this cosmic galaxy portrait. In fact, it’s almost the size of our Milky Way Galaxy. NGC 4945’s own dusty disk, young blue star clusters, and pink star forming regions standout in the sharp, colorful telescopic image. About 13 million light-years distant toward the expansive southern constellation Centaurus, NGC 4945 is only about six times farther away than Andromeda, the nearest large spiral galaxy to the Milky Way. Though this galaxy’s central region is largely hidden from view for optical telescopes, X-ray and infrared observations indicate significant high energy emission and star formation in the core of NGC 4945….