Free Astronomy Magazine November-December 2023 ARABIC VERSION

20,000-year-old explosion continues expanding into space by NASA/ESA Ray Villard hough a doomed star ex- ploded some 20,000 years ago, its tattered remnants continue racing into space at breakneck speeds – and NASA’s Hubble Space Telescope has caught the action. The nebula, called the Cygnus Loop, forms a bubble-like shape that is about 120 light-years in diameter. The distance to its center is approx- imately 2,600 light-years. The entire nebula has a width of six full Moons as seen on the sky. Astronomers used Hubble to zoom into a very small slice of the leading edge of this expanding supernova bubble, where the supernova blast wave plows into surrounding mate- rial in space. Hubble images taken from 2001 to 2020 clearly demon- strate how the remnant’s shock front has expanded over time, and they used the crisp images to clock its speed. By analyzing the shock’s location, astronomers found that the shock hasn’t slowed down at all in the last 20 years, and is speeding into inter- stellar space at over half a million miles per hour – fast enough to ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 44 اﻧﻔﺠﺎر ﻋﻤﺮﻩ 20 أﻟﻒﻋﺎم ﻻ ﻳﺰال ﺘﻮﺳﻊ ﻓﻲاﻟﻔﻀﺎء : ﻘﻠﻢ رايﻓ ﻼرد و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻻوروﺑ ﺔ ـــ ﻧﺠﻤﺎً ﻛﺎن ﻣﺼ ه اﻟﻔﻨﺎء ﻗﺪ اﻧﻔﺠﺮ ﻣﻨﺬ ﺣﻮاﱄ 20 أﻟﻒ ﻋﺎم وﻟﻜﻦ ﻋﲆ اﻟﺮﻏﻢ ﻣﻦ ذﻟﻚ ﻓﺈن ﺑﻘﺎﻳﺎه ا ﻤﺰﻗﺔ اﻻﻧﻄﻼق ﰲ ة ﺴﺘﻤﺮ ﻣ إﱃ اﻟﻔﻀﺎء ﺑـ ـ ﴪﻋﺎت ﻓﺎﺋﻘـﺔ وﻗـﺪ اﻛﺘﺸـﻒ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ اﻟﺘـﺎﺑﻊ ﻟ ﻮﻛﺎﻟـﺔ ﻧﺎﺳـﺎ ﻫـﺬا اﻟﺤﺪث . اﻟﺤﺪث . ﻳﺸﻜﻞ اﻟﺴﺪﻳﻢ اﻟﺬي ﻳﺴﻤﻰ ﻗﻮس " اﻟﺪﺟﺎﺟﺔ " ﺷﻜﻼً ﻳﺸﺒﻪ اﻟﻔﻘﺎﻋﺔ ﻳﺒﻠﻎ ﻗﻄﺮه ﺣﻮاﱄ 120 ﺳﻨﺔ ﺿﻮﺋﻴﺔ وﺗﺒﻠﻎ ا ﺴـﺎﻓﺔ إﱃ ﺰه ﻣﺮﻛ ﺣﻮاﱄ 2600 ﺳﻨﺔ ﺿﻮﺋﻴﺔ وﻳﺴـﺎوي ﻋﺮض اﻟﺴﺪﻳﻢ ﺑﺄﻛﻤﻠﻪ ﻋﺮض ﺳـﺘﺔ أﻗﻤـﺎر ﺑﺪور ﺗ ﻛﻤﺎ ﻈﻬﺮ ﰲ اﻟﺴـﻤﺎء أي ) 3 درﺟـﺎت ( ﺳﻤﺎوﻳﺔ . اﺳﺘﺨﺪم اﻟ ﻌﻠﻤﺎء ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ ﻟﺘﻜﺒ ﴍﻳﺤﺔ ﺻـﻐ ة ﺟـﺪ اً ﻣـﻦ اﻟﺤﺎﻓـﺔ اﻷﻣﺎﻣﻴﺔ ﻟﻔﻘﺎﻋﺔ ا ﺴﺘﻌﺮ اﻷﻋﻈﻢ ا ﺘﻮﺳﻌﺔ ﺣﻴـﺚ ﺗﺼـﻄﺪم ﻣﻮﺟـﺔ اﻧﻔﺠـﺎر ا ﺴـﺘﻌﺮ اﻷﻋﻈﻢ ﺑﺎ ﻮا د ا ﺤﻴﻄﺔ ﰲ اﻟﻔﻀـﺎء . ﺗُﻈﻬـﺮ اﻷﻋﻈﻢ ﺑﺎ ﻮاد ا ﺤﻴﻄﺔ ﰲ اﻟﻔﻀـﺎء . ﺗُﻈﻬـﺮ ﺗﻠﺴﻜﻮب ﺻﻮر ﻫﺎﺑـﻞ ا ﻠﺘﻘﻄـﺔ ﻣـﻦ ﻋـﺎم 2001 إﱃ ﻋﺎم 2020 ﺑﻮﺿﻮح ﻛﻴﻒ ﺗﻮﺳﻌﺖ ﻣﻘﺪﻣﺔ اﻟﺼﺪﻣﺔ ا ﺘﺒﻘﻴﺔ ﻣﻊ ﻣـﺮور اﻟﻮﻗـﺖ واﺳﺘﺨ ﺪﻣﻮا اﻟﺼﻮر ﻟﻘﻴﺎسﴎﻋﺘﻬـﺎ وﻣـﻦ ﺧﻼل ﺗﺤﻠﻴﻞ ﻣﻮﻗﻊ اﻟﺼﺪﻣﺔ اﻟ وﺟﺪ ﻌﻠﻤﺎء أن اﻟﺼﺪﻣﺔ ﻟـ ﻢ ﺗﺘﺒﺎﻃـﺄ ﻋـﲆ اﻹﻃـﻼق ﺧـﻼل اﻟﻌﴩﻳﻦ ﻋﺎﻣﺎً ا ﺎﺿـﻴﺔ وأﻧﻬـﺎ ﺗﺘﺴـﺎرع ﰲ اﻟﻔﻀﺎء ﺑ اﻟﻨﺠﻮم ﺑﴪﻋﺔ ﺗﺰﻳﺪ ﻋﻦ ﻧﺼﻒ ﻣﻠﻴﻮن ﻣﻴﻞ ﺑ ﺎﻟﺴﺎﻋﺔ وﻫـﻲ ﴎﻋـﺔ ﻛﺎﻓﻴـﺔ ﻟﺮﺻﺪﻫﺎ .. ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 3 إن