Free Astronomy Magazine September-October 2023 ARABIC VERSION

2022 using an instrument on the Canada-France-Hawaii Telescope that can detect and measure mag- netic fields. The team also relied on key archive data taken with the Fiber-fed Extended Range Optical Spectrograph (FEROS) at ESO’s La Silla Observatory in Chile. Once the observations were in, Shenar asked co-author Gregg Wade, an expert on magnetic fields in stars at the Royal Military College of Canada, to examine the data. Wade’s response confirmed Shenar’s hunch: “Well my friend, whatever this thing is — it is definitely magnetic.” Shenar’s team had found that the star has an in- credibly strong magnetic field, of 43,000 gauss, making HD 45166 the most magnetic massive star found to date. “The entire surface of the helium star has a magnetic field al- most 100,000 times stronger than Earth’s,” explains co-author Pablo Marchant, an astronomer at KU Leuven’s Institute of Astronomy in Belgium. This observation marks the discov- ery of the very first massive mag- netic helium star. “It is exciting to uncover a new type of astronomical object, — says Shenar, — especially when it’s been hiding in plain sight all along.” Moreover, it provides clues to the origin of magnetars, compact dead stars laced with magnetic fields at least a billion times stronger than the one in HD 45166. The team’s cal- culations suggest that this star will end its life as a magnetar. As it col- lapses under its own gravity, its magnetic field will strengthen, and the star will eventually become a very compact core with a magnetic field of around 100 trillion gauss — the most powerful type of magnet in the Universe. Shenar and his team also found that HD 45166 has a mass smaller than previously reported, around twice the mass of the Sun, and that its stellar pair orbits at a far larger dis- tance than believed before. Further- more, their research indicates that HD 45166 formed through the merger of two smaller helium-rich stars. “Our findings completely re- shape our understanding of HD 45166,” concludes Bodensteiner.     ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 47 ُﻈﻬـﺮﻫـﺬا اﻟﺮﺳـﻢ اﻟﺘﺨ ﻠـﻲ HD 4516 ـﻢﺿـ ﻢ اﻛﺘﺸـﻒﻣـﺆﺧﺮ وﻫـﻮ ﻧ اً أﻧـﮫ ﻤﺘﻠـﻚ ﻣﺠـﺎ ﻻً ﻣﻐﻨﺎﻃ ﺴـ ﺎً ﻗﻮ ًﺎ ﻳ ﻠﻎ 4300 ـﻢﺿـ ﻢ ﻏﺎوس، وﻫﻮ أﻗـﻮىﻣﺠـﺎل ﻣﻐﻨﺎﻃ ﺴـﻲ ﺗـﻢ اﻛﺘﺸـﺎﻓﮫ ﻋﻠـﻰ اﻹﻃـﻼق ﻓـﻲ ﻧ . ﺘﻢ اﺣﺘﺠﺎز اﻟﺮ ﺎح اﻟﺸﺪ ﺪة اﻟﻤ ﻮﻧﺔ ﻣﻦ اﻟ ـ ﺗﻨﻄﻠﻖ ﻌ ﺪ ﺠﺴ ﻤﺎت اﻟ اً ﻋـﻦ اﻟـﻨ ﻢ ﺑﻮاﺳـﻄﺔ ﻫـﺬا اﻟﻤﺠـﺎل اﻟﻤﻐﻨﺎﻃ ﺴﻲ ﻣﻤﺎ ﻐﻠﻒ اﻟﻨ ﻢ ﻐﻼفﻏﺎزي ﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﻫﻨﺎ [ESO/L. Calçada]. ﺗﻢ إﺟﺮاء اﻷرﺻﺎد اﻟﺮﺋﻴﺴﻴﺔ ﰲ ﻓﱪاﻳـﺮ 2022 ﺑﺎﺳــﺘﺨﺪام أداة ﻣﻮﺟــﻮدة ﰲ اﻟﺘﻠﺴــﻜﻮب اﻟﻜﻨﺪي اﻟﻔﺮﻧﴘ ﻫـﺎواي ﻳﻤﻜﻨﻬـﺎ اﻛﺘﺸـﺎف وﻗﻴﺎس ا ﺠﺎﻻت ا ﻐﻨﺎﻃﻴﺴﻴﺔ . اﻋﺘﻤﺪ اﻟﻔﺮﻳﻖ أﻳﻀًﺎ ﻋﲆ ﺑﻴﺎﻧﺎت اﻷرﺷﻴﻒ اﻟﺮﺋﻴﺴﻴﺔ ا ﺄﺧﻮذة ﺑﺎﺳﺘﺨﺪام ﻣﻄﻴﺎف ﺑﴫي ﻣﻤﺘﺪ ا ﺪى ﻣﺰوّد ﺑﺎﻷﻟﻴﺎف ) ﰲ ( ﻓﻴ وس ﻣﺮﺻﺪ ﻻﺳﻴﻼ اﻟﺘـﺎﺑﻊ ﻟﻠﻤﺮﺻﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ ﰲ ﺗﺸﻴﲇ . ﺑﻤﺠﺮد إدﺧﺎل ﺑﻴﺎﻧﺎت اﻟﺮﺻﺪ ﻃﻠـﺐ ﺷـ ﻴﻨﺎر ﻣﻦ ا ﺆﻟﻒ ا ﺸـﺎرك ﺟـﺮﻳﺞ وﻳـﺪ اﻟﺨﺒـ ﰲ ا ﺠﺎﻻت ا ﻐﻨﺎﻃﻴﺴـﻴﺔ ﰲ اﻟﻨﺠـﻮم ﰲ اﻟﻜﻠﻴـﺔ اﻟﻌﺴﻜﺮ ﻳﺔ ا ﻠﻜﻴﺔ ﰲ ﻛﻨﺪا ﻓﺤـﺺ اﻟﺒﻴﺎﻧـﺎت . ـــ أﻛﺪ رد واﻳﺪ ﺣﺪس ﺷﻨﺎر ": ﺣﺴﻨًﺎ ﻳﺎ ﺻﺪﻳﻘﻲ ﻣﻬﻤﺎ ﻛـﺎن ﻫـﺬا اﻟﺸـ ـ ﻲء، ﻓﻬـﻮ ﺑﺎﻟﺘﺄﻛﻴـﺪ ." ﻴﴘـ ﻣﻐﻨﺎﻃ ﻟﻘﺪ وﺟـﺪ أن اﻟـﻨﺠﻢ ﻳﺘﻤﺘـﻊ ﺑﻤﺠﺎل ﻣﻐﻨﺎﻃﻴﴘ ﻗﻮي ﺟـﺪاً ﻳﺒﻠـﻎ 43000 ﻏﺎوس ﻣﻤﺎ ﻳﺠﻌﻞ HD 45166 أﻛﺜﺮ اﻟﻨﺠـﻮم ا ﻐﻨﺎﻃﻴﺴﻴﺔ اﻟﻀﺨﻤﺔ اﻟﺘﻲ ﺗﻢ اﻟﻌﺜﻮر ﻋﻠﻴﻬﺎ . ﺣﺘـﻰ اﻵن ﻳﻮﺿـ ﺢ ا ﺆﻟـﻒ ا ﺸـﺎرك ﺑـﺎﺑﻠﻮ ﻣﺎرﺷﺎﻧﺖ ﻣﻦ ﺟﺎﻣﻌﺔ ﻟﻮﻓﺎن اﻟﻜﺎﺛﻮﻟﻴﻜﻴـﺔ ﰲ ﺑﻠﺠﻴﻜﺎ " : ﻳﺤﺘﻮي ﺳﻄﺢ ﻧﺠﻢ اﻟﻬﻠﻴﻮم ﺑﺄﻛﻤﻠﻪ ﻋﲆ ﻣﺠﺎل ﻣﻐﻨﺎﻃﻴﴘ أﻗﻮى ﺑﻨﺤﻮ 100 أﻟﻒ ﻣﺮة ﻣﻦ ﻣﺠﺎل اﻷرض ." ﺗﻤﺜﻞ ﻫﺬه ا ﻼﺣﻈﺔ اﻛﺘﺸـﺎف أول ﻧﺠـﻢ ﻫﻴﻠﻴـﻮم ﻣﻐﻨﺎﻃـ ﻴﴘ ـ . ﺿﺨﻢ ﻳﻘﻮل ﺷﻴﻨﺎر " : ﻣـﻦ ا ﺜـ اﻛﺘ ﺸـﺎف ﻧﻮع ﺟﺪﻳﺪ ﻣـﻦ اﻷﺟﺴـﺎم اﻟﻔﻠﻜﻴـﺔ ﺧﺎﺻـﺔ ﻋﻨﺪﻣﺎ ﻛﺎن ﻋﲆ ﻣـﺮأى ﻣـﻦ اﻟﺠﻤﻴـﻊ ﻃـﻮال اﻟﻮﻗﺖ ﻋﻼوة ﻋﲆ ذﻟﻚ ﻓﺈﻧﻪ ﻳﻮﻓﺮ أدﻟﺔ ﺣـﻮل أﺻﻞ اﻟﻨﺠﻮم ا ﻐﻨﺎﻃﻴﺴﻴﺔ وﻫﻲ ﻧﺠﻮم ﻣﻴﺘﺔ ﻣﺪﻣﺠﺔ ﻣﺤﺎﻃﺔ ﺑﻤﺠﺎﻻت ﻣﻐﻨﺎﻃﻴﺴﻴﺔ أﻗﻮى ﺑﻤﻠﻴﺎر ﻣﺮة ﻋﲆ اﻷﻗﻞ ﻣـﻦ ﺗﻠـﻚ ا ﻮﺟـﻮدة ﰲ HD 45166 . وﺗﺸ ﺣﺴﺎﺑﺎت اﻟﻔﺮﻳﻖ إﱃ أن ﻫﺬا ا ﻟﻨﺠﻢ ﺳﻴﻨﻬﻲ ﺣﻴﺎﺗﻪ ﻛﻨﺠﻢ ﻣﻐﻨﺎﻃ ﻴﴘـ ﻋﻨﺪﻣﺎ ﻳﻨ ﻬﺎر ﺗﺤﺖ ﺟﺎذﺑﻴﺘﻪ و ﺳﻴﻘﻮى ﻣﺠﺎﻟﻪ ا ﻐﻨﺎﻃﻴ ﴘـ وﺳﻴﺼﺒﺢ اﻟﻨﺠﻢ ﰲ اﻟ ﻨﻬﺎﻳﺔ ﻧﻮاة ﻣﺪﻣﺠﺔ ﻟﻠﻐﺎﻳﺔ ﻣﻊ ﻣﺠﺎل ﻣﻐﻨﺎﻃﻴ ـ ﴘ ﻳﺒﻠـﻎ ﺣﻮاﱄ 100 ﺗﺮﻳﻠﻴﻮن ﻏﺎوس وﻫﻮ أﻗﻮى ﻧـﻮع ﻣﻦ ا ﻐﻨﺎﻃﻴﺲ ﰲ اﻟﻜـﻮن و وﺟـﺪ أﻳﻀـ أن ﺎً ﻛﺘﻠﺔ HD 45166 أﺻﻐﺮ ﻣﻤﺎ أﻋﻠﻦ أي ﺎً ﺳﺎﺑﻘ ﺣﻮاﱄ ﺿـﻌﻒ ﻛﺘﻠـﺔ اﻟﺸـﻤﺲ وأن ﻣﺮاﻓﻘـﻪ اﻟﻨﺠﻤﻲ ﻳﺪور ﻋﲆ ﻣﺴﺎﻓﺔ أﻛﱪ ﺑﻜﺜـ ﻣﻤـﺎ ﻛﺎن ﻳﻌﺘﻘﺪ ﺳﺎﺑﻘﺎً . ﺗﺸ أﺑﺤﺎﺛﻬﻢ إﱃ أن HD 45166 ﺗﺸﻜﻞ ﻣﻦ اﻧـﺪﻣﺎج ﻧﺠﻤـ أﺻـﻐﺮ ﺣﺠﻤﺎ وﻏﻨﻴ ﺑﺎﻟﻬﻠﻴﻮم . وﻳﺨﺘﺘﻢ ﺑﻮدﻧﺸﺘﺎﻳﻨﺮ : " ﻗﺎﺋﻼً إن اﻟﻨﺘﺎﺋﺞ اﻟﺘﻲ ﺗﻮﺻﻠﻨﺎ إﻟﻴﻬـﺎ ﺗﻌﻴـﺪ ﺗﺸﻜﻴﻞ ﻓﻬﻤﻨﺎ ﻟـ HD 45166 ﺑﺎﻟﻜﺎﻣﻞ ." - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 3