Free Astronomy Magazine November-December 2023 ARABIC VERSION

T T his artist’s impression illustrates the ultimate fate of HD 45166 after its core has collapsed, resulting in a neutron star with a magnetic field of around 100 trillion gauss — the most powerful type of magnet in the Universe. [NOIRLab/AURA/NSF/ P. Marenfeld/M. Zamani] team were able to make precise es- timates of its mass and age. The researchers speculate that, un- like other helium stars that eventu- ally evolve from a red supergiant, this particular star was likely created by the merger of a pair of interme- diate-mass stars. “This is a very specific scenario, and it raises the question of how many magnetars come from similar sys- tems and how many come from other types of systems,” said Chené. In a few million years, HD 45166, which is located 3000 light-years away in the constellation Monoceros (the Unicorn), will explode as a very bright, but not particularly ener- getic, supernova. During this explo- sion, its core will contract, trapping and concentrating the star’s already daunting magnetic field lines. The result will be a neutron star with a magnetic field of around 100 trillion gauss — the most powerful type of magnet in the Universe. “We thought that the most likely magnetar candidates would come from the most massive of stars,” said Chené. “What this research shows us is that stars that are much less mas- sive can still become a magnetar, if the conditions are just right.”  his artist’s impression illustrates how, in a few million years, HD 45166 will explode as a very bright, but not particularly energetic, super- nova. During this explosion, its core will contract, trapping and concentrat- ing the star’s already daunting mag- netic field lines. [NOIRLab/AURA/NSF/ P. Marenfeld/M. Zamani] ﺗﻤﻜﻦ اﻟﻔﺮﻳﻖ ﻣﻦ إﺟﺮاء ﺗﻘـﺪﻳﺮات دﻗﻴﻘـﺔ ﻟﻜﺘﻠﺘﻪ وﻋﻤﺮه وﻳﺘﻜﻬﻦ اﻟﺒﺎﺣﺜ ﻮن ﺑﺄﻧﻪ ﻋـﲆ ﻋﻜﺲ ﻧﺠﻮم اﻟﻬﻴﻠﻴﻮم اﻷﺧﺮى اﻟﺘﻲ ﺗﺘﻄـﻮر ﰲ ﻧﻬﺎﻳﺔ ا ﻄﺎف ﻣﻦ ﻋﻤﻼق أﺣﻤﺮ ﻓﺎﺋﻖ، ﻣﻦ ا ﺤﺘﻤﻞ أن ﻳﻜﻮن ﻫﺬا اﻟﻨﺠﻢ ﺑﺎﻟﺬات ﻗﺪ ﺗـﻢ إﻧﺸﺎؤه ﻋﻦ ﻃﺮﻳﻖ اﻧﺪﻣﺎج زوج ﻣﻦ اﻟﻨﺠﻮم ﻣﺘﻮﺳـﻄﺔ اﻟﻜﺘﻠــﺔ . ﻗــﺎل ﺗﺸـﻴﻨﻲ " : ﻫــﺬا ﺳﻴﻨﺎرﻳﻮ ﻣﺤـﺪد ﻟﻠﻐﺎﻳـﺔ، وﻳﺜـ ﺗﺴـﺎؤﻻت ﺣﻮل ﻋﺪد اﻟﻨﺠﻮم ا ﻐﻨﺎﻃﻴﺴﻴﺔ ا ﻟﺘﻲ ﺗﺄﺗﻲ ﻣﻦ أﻧﻈﻤﺔ ﻣﻤﺎﺛﻠﺔ وﻋﺪد اﻟﻨﺠﻮم اﻟﺘﻲ ﺗـﺄﺗﻲ ﻣﻦ أﻧﻮاع أﺧﺮى ﻣﻦ اﻷﻧﻈﻤﺔ . ﺧﻼل ﺑﻀـﻌﺔ ﻣﻼﻳ ﻣﻦ اﻟﺴـﻨ ﺳـﻴﻨﻔﺠﺮ HD 45166 ، اﻟ ﺬي ﻳﺒﻌﺪ ﻣﺴـﺎﻓﺔ 3000 ﺳـﻨﺔ ﺿـﻮﺋﻴﺔ ﰲ ﻛﻮﻛﺒﺔ وﺣﻴﺪ اﻟﻘﺮ ن ﻛﻤﺴﺘﻌﺮ أﻋﻈﻢ ﺷـﺪﻳﺪ اﻟﺴﻄﻮع وﻟﻜﻦ ﻟﻴﺲ ﻧﺸ . ﻄًﺎ ﺧﻼل ﻫﺬا اﻻﻧﻔﺠﺎر ﺳـﻮف ﻳـﻨﻜﻤﺶ ﻗﻠـﺐ اﻟـﻨﺠﻢ ﻣﻤـﺎ ﻳـﺆدي إﱃ ﻣﺤـﺎﴏة وﺗﺮﻛﻴـﺰ ﺧﻄﻮط ا ﺠﺎل ا ﻐﻨﺎﻃﻴﴘ ا ﺮﻫﻘﺔ ﺑﺎﻟﻔﻌﻞ ﻟﻠﻨﺠﻢ وﺳﺘﻜﻮن اﻟﻨﺘﻴﺠـﺔ ﻧﺠﻤًـﺎ ﻧﻴﻮﺗﺮوﻧﻴـﺎً ﺑﻤﺠﺎل ﻣﻐﻨﺎﻃﻴﴘ ﻳﺒﻠﻎ ﺣﻮاﱄ 100 ﺗﺮﻳﻠﻴﻮن ﻏﺎوس وﻫﻮ أﻗﻮى ﻧﻮع ﻣـﻦ ا ﻐﻨـﺎﻃﻴﺲ ﰲ اﻟﻜﻮن . ﻗﺎل ﺗﺸﻴﻨﻲ " : ﻛﻨﺎ ﻧﻈﻦ أن ا ﺮﺷﺤ اﻷﻛﺜﺮ اﺣﺘﻤﺎﻻً ﻟﻠﻨﺠﻮم ا ﻐﻨﺎﻃﻴﺴﻴﺔ ﺄﺗﻲﺳﺘ ﻣﻦ اﻟﻨﺠﻮم اﻷﻛﺜﺮ ﺿﺨﺎﻣﺔ و ﻣﺎ ﻳﻮﺿﺤﻪ ﻟﻨﺎ ﻫﺬا اﻟﺒﺤﺚ ﻫﻮ أن اﻟﻨﺠﻮم اﻷﻗﻞ ﻛﺘﻠﺔً ﺑﻜﺜ ﻳﻤﻜﻦ أن ﺗﺼﺒﺢ ﻧﺠﻤًﺎ ﻣﻐﻨﺎﻃﻴﺴﻴﺎً إذا ﻛﺎﻧﺖ اﻟﻈﺮوف ﻣﻨﺎﺳﺒﺔ ﺗﻤﺎﻣ ." ﺎً ﻳﻮﺿـــــــــﺢﻫــــــــــﺬا اﻟﺮﺳــــــــــﻢ اﻟﺘﺨ ﻠــــــــــﻲاﻟﻤﺼــــــــــ اﻟﻨﻬـﺎﺋﻲﻟــﻠﻨ ﻢ HD 45166 ﻌـﺪ أن ــــــﻢ إﻟـــــﻰﻇﻬـــــﻮرﻧ ــــــﮫ ﻣﻤـــــﺎ أد اﻧﻬـــــﺎرﻗﻠ ﻧﻴــــــــــﻮﺗﺮوﻧﻲ ﻤﺠــــــــــﺎلﻣﻐﻨﺎﻃ ﺴــــــــــﻲ ﻳ ﻠــــــــــﻎ ﺣــﻮاﻟﻲ 100 ﺗﺮ ﻠﻴــﻮنﻏـــﺎوسوﻫـــ ﻮ أﻗــﻮى أﻧﻮاع ﻣﻦ اﻟﻤﻐﻨﺎﻃ ﺲﻓﻲاﻟ .ﻮن ـــﻒﺳـــ ﻨﻔﺠﺮ ﻳﻮﺿـــﺢﻫــــﺬا اﻟﺮﺳـــﻢ اﻟﺘﺨ ﻠــــﻲﻛ اﻟـﻨ ﻢ HD 4516 ﻣـﻦ ﺧـﻼل ﻀـﻌﺔ ﻣﻼﻳـ ﻓــــﻲﺻــــﻮرة ﻣﺴــــﺘﻌﺮأﻋﻈــــﻢﺷـــــﺪ ﺪ اﻟﺴــــﻨ اﻟﺴـــــﻄﻮع وﻟ ﻜــــــﻦ ﻟــــــ ﺲﻧﺸــــــﻄًﺎ وﺧــــــﻼلﻫـــــﺬا ـــــﻨ ﻤﺶﻗﻠـــــﺐاﻟـــــﻨ ﻢ اﻻﻧﻔﺠـــــﺎرﺳـــــﻮف ﻣﻤـــــﺎ إﻟــﻰاﺣﺘﺠـــﺎزوﺗــﺮﻛ ﺧﻄــﻮطاﻟﻤﺠـــﺎل ﻳــﺆد اﻟﻤﻐﻨﺎﻃ ﺴﻲﻟﻠﻨ ﻢ اﻟﻤﺮﻫﻘﺔ ﺎﻟﻔﻌﻞ .