Free Astronomy Magazine November-December 2022 ARABIC VERSION

Pair-instability supernova explosions happen when photons in the center of a star spontaneously turn into electrons and positrons — the posi- tively charged antimatter counter- part to the electron. This conversion reduces the radiation pressure inside the star, allowing gravity to over- come it and leading to the collapse and subsequent explosion. Unlike other supernovae, these dra- matic events leave no stellar rem- nants, such as a neutron star or a black hole, and instead eject all their material into their surroundings. There are only two ways to find evi- dence of them. The first is to catch a - pens, way NOVEMBER-DECEMBER 2022 ُﻈﻬــــﺮ ﻫــــﺬا اﻟﺮﺳــــﻢ اﻟﻔــــ ﺣﻘــــﻞ ﻣــــﻦ ﻧﺠــــﻮم اﻟـــــ ﻤﻬﺮة اﻟﺜﺎﻟﺜــــﺔ ــــﺚ ﺣ ﺘﻮﻗــــﻊ أﻧﻬــــﺎ ﺗﺸــــ ﻠﺖ ﻌــــﺪ ﺣــــﻮاﻟﻲ ١٠٠ ﻣﻠﻴــــﻮنﺳــــﻨﺔ ﻓﻘــــﻂﻣــــﻦ اﻻﻧﻔﺠــــﺎر اﻟﻌﻈــــ ﻢ . رﻤــــﺎ اﻛﺘﺸــــﻒﻋﻠ ﻤــــﺎء اﻟﻔﻠــــﻚ اﻟﻌﻼﻣــــﺎت اﻷوﻟﻰ ﻟ ﻘ ﺎﻫﺎ ـﻮازارات اﻟـ اﻟﻜ ﻤ ﺎﺋ ﺔ اﻟﻘﺪ ﻤﺔ ﻓـﻲ اﻟﺴـﺤﺐ اﻟﻤﺤ ﻄـﺔ ﺑﻮاﺣـﺪ ﻣـﻦ أ ﻌـﺪ اﻟ ﺗـﻢ اﻛﺘﺸﺎﻓﻬﺎ ﻋﻠﻰ اﻹﻃﻼق . ﺗﺤﺪث اﻧﻔﺠﺎرات ا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ اﻟﺜﻨﺎﺋﻴﺔ ﻏـ ا ﺴـﺘﻘﺮة ﻋﻨـﺪﻣﺎ ﺗﺘﺤـﻮل اﻟﻔﻮﺗﻮﻧـﺎت ا ﻮﺟــﻮدة ﰲ ﻣﺮﻛــﺰ اﻟــﻨﺠﻢ ﺗﻠﻘﺎﺋﻴًــﺎ إﱃ إﻟﻜﱰوﻧﺎت وﺑﻮزﻳﱰوﻧﺎت وﻫﻲ ا ﺎدة ا ﻀﺎدة ﻣﻮﺟﺒﺔ اﻟﺸﺤﻨﺔ ا ﻀﺎدة ﻟﻺﻟﻜـﱰون . ﻳﻘﻠـﻞ ﻫﺬا اﻟﺘﺤﻮﻳﻞ ﻣﻦ ﺿﻐﻂ اﻹﺷﻌﺎع داﺧﻞ اﻟﻨﺠﻢ ﻣﻤﺎ ﻳﺴﻤﺢ ﻟﻠﺠﺎذﺑﻴـﺔ ﺑﺘﺠـﺎوزه وﻳـﺆدي إﱃ اﻻﻧﻬﻴـﺎر واﻻﻧﻔﺠـﺎر ﻻﺣﻘـﺎً . ﻓﻌـﲆ ﻋﻜـﺲ ا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ اﻷﺧـﺮى ﻻ ﺗـﱰك ﻫـﺬه اﻷﺣﺪاث اﻟﺪراﻣﻴﺔ أي ﺑﻘﺎﻳﺎ ﻪ ﻧﺠﻤﻴ ، ﻣﺜﻞ ﻧﺠﻢ ﻧﻴﻮﺗﺮوﻧﻲ أو ﺛﻘﺐ أﺳـﻮد ، وﺑـﺪﻻً ﻣـﻦ ذﻟـﻚ ﺗﻘ ـﺬف ﻛ ـﻞ ﻣﻮادﻫ ـﺎ ﰲ ﻣﺤﻴﻄﻬ ـﺎ . ﻫﻨ ـﺎك ﻃﺮ ﻳﻘﺘﺎن ﻓﻘـﻂ ﻟﻠﻌﺜـﻮر ﻋـﲆ دﻟﻴـﻞ ﻋﻠﻴﻬـﺎ ـ ـــــ اﻷول ﻫﻮ اﻟﺘﻘﺎط ﻣﺴﺘﻌﺮ أﻋﻈﻢ ﺛﻨﺎﺋﻲ ﻏـ ﻣﺴﺘﻘﺮ ﻓﻮر ﺣﺪوﺛﻪ وﻫﻮ أﻣﺮ ﻏـ ﻣﺤﺘﻤـﻞ اﻟﺤﺪوث اﻟﻄﺮﻳﻘﺔ اﻷﺧﺮى ﺗﺤﺪﻳـﺪ اﻟﺒﺼـﻤﺔ اﻟﻜﻴﻤﻴﺎﺋﻴ ﻟ ﺔ ﻠﻤﺎدة اﻟﺘﻲ ﺗﻘـﺬﻓﻬﺎ ﰲ اﻟﻔﻀـﺎء ﺑ اﻟﻨﺠﻮم اﻟ درس ﻌﻠﻤـﺎء ﻧﺘـﺎﺋﺞ اﻟﺮﺻـﺪ اﻟﺴﺎﺑﻖ ﺑﻮاﺳﻄﺔ ﺗﻠﺴﻜﻮب ﺟﻴﻤﻴﻨـﻲ ﻧـﻮرث اﻟﺒﺎﻟﻎ ٨.١ ﻣﱰ ﺑﺎﺳﺘﺨﺪام ﻣﻄﻴـﺎف ﻤﻴﻨـﻲ ﺟﻴ ﻟﻸﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﻘﺮﻳﺒﺔ ﻳﻘﺴﻢ اﻟﻀﻮء ا ﻨﺒﻌﺚ ﻣﻦ اﻷﺟـﺮام اﻟﺴـﻤﺎوﻳﺔ إﱃ اﻷﻃـﻮال ا ﻮﺟﻴﺔ ا ﻜﻮﻧﺔ ﻟﻪ واﻟﺘﻲ ﺗﺤﻤـﻞ ﻣﻌﻠﻮﻣـﺎت ﺣﻮل اﻟﻌﻨﺎﴏ ا ﻮﺟـﻮدة ﰲ ﻫـﺬه اﻷﺟﺴـﺎم . ﺗﻠﺴﻜﻮب ﺟﻴﻤﻴﻨﻲ ﺿﻤﻦ اﻟﺘﻠﺴﻜﻮﺑﺎت اﻟﻘﻠﻴﻠﺔ ا ﻨﺎﺳـــﺒﺔ ﻷداء ﻣﺜـــﻞ ﻫـــﺬه اﻷرﺻـــﺎد . ـــــــــــ ﻧﻮﻓﻤ دﻳﺴﻤ 2022