M27: 哑铃星云

M27: 哑铃星云

ByNASA中文

2019 December 3 M27: The Dumbbell Nebula Image Credit & Copyright: Steve Mazlin Explanation: Is this what will become of our Sun? Quite possibly. The first hint of our Sun’s future was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier’s list, now known as M27 or the Dumbbell Nebula, is a planetary nebula, the type of nebula our Sun will produce when nuclear fusion stops in its core. M27 is one of the brightest planetary nebulae on the sky, and can be seen toward the constellation of the Fox (Vulpecula) with binoculars. It takes light about 1000 years to reach us from M27, featured here in…

MyCn 18；沙漏星云

MyCn 18；沙漏星云

ByGotthew

2019 September 29 MyCn 18: The Engraved Hourglass Planetary Nebula Image Credit: NASA, ESA, Hubble; Processing & License: Judy Schmidt Explanation: Do you see the hourglass shape — or does it see you? If you can picture it, the rings of MyCn 18 trace the outline of an hourglass — although one with an unusual eye in its center. Either way, the sands of time are running out for the central star of this hourglass-shaped planetary nebula. With its nuclear fuel exhausted, this brief, spectacular, closing phase of a Sun-like star’s life occurs as its outer layers are ejected – its core becoming a cooling, fading white dwarf. In 1995, astronomers used the Hubble Space Telescope (HST) to make a series of images of planetary…