保护地球，探索宇宙，发现文明
2020年10月16日 Planetary Nebula Abell 78 Image Credit & Copyright: Bernhard Hubl Explanation: Planetary nebula Abell 78 stands out in this colorful telescopic skyscape. In fact the colors of the spiky Milky Way stars depend on their surface temperatures, both cooler (yellowish) and hotter (bluish) than the Sun. But Abell 78 shines by the characteristic emi...
2020年9月13日 M2-9: Wings of a Butterfly Nebula Image Credit: Hubble Legacy Archive, NASA, ESA – Processing: Judy Schmidt Explanation: Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured here, the stars transform the...
2020年8月23日 The Helix Nebula from Blanco and Hubble Image Credit: C. R. O’Dell, (Vanderbilt) et al. ESA, NOAO, NASA Explanation: How did a star create the Helix nebula? The shapes of planetary nebula like the Helix are important because they likely hold clues to how stars like the Sun end their lives. Observations by the orbiting Hubble Space Telescope ...
2020年8月14日 NGC 5189: An Unusually Complex Planetary Nebula Image Credit: NASA, ESA, Hubble, HLA; Reprocessing & Copyright: Jesús M. Vargas Explanation: Why is this nebula so complex? When a star like our Sun is dying, it will cast off its outer layers, usually into a simple overall shape. Sometimes this shape is a sphere, sometimes a double lobe, and so...
2020 June 30 Bright Planetary Nebula NGC 7027 from Hubble Image Credit: NASA, ESA, Joel Kastner (RIT) et al.; Processing: Alyssa Pagan (STScI) Explanation: What created this unusual planetary nebula? NGC 7027 is one of the smallest, brightest, and most unusually shaped planetary nebulas known. Given its expansion rate, NGC 7027 first started expanding, as vi...
2020 June 7 Halo of the Cat’s Eye Image Credit & Copyright: R. Corradi (Isaac Newton Group), Nordic Optical Telescope Explanation: The Cat’s Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the eno...
2020 February 16 NGC 2392: Double-Shelled Planetary Nebula Image Credit: NASA, ESA, Hubble, Chandra; Processing & License: Judy Schmidt Explanation: To some, this huge nebula resembles a person’s head surrounded by a parka hood. In 1787, astronomer William Herschel discovered this unusual planetary nebula: NGC 2392. More recently, the Hubble Space ...
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...
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, th...