Free Astronomy Magazine November-December 2025 ARABIC VERSION

hisvideoillustratesthesupernovaexplosionSN2021yfjand the formation ofits remnant.[Keck Obs./Adam Makarenko] - - - s hydrogen and helium. But the newly discovered super- nova,dubbedSN2021yfj,displayed a startling different chemical signa- ture containing silicon, sulfur and argon, suggesting it somehow lost itsouterhydrogen,helium,carbon, oxygen, neon, and magnesium lay- ers—exposingtheinnersiliconand sulfur-rich layers — immediately be- fore exploding. Astronomers have long proposed thatmassivestarspossessanonion- like layered structure, with the lightest elements in the outermost shells and progressively heavier ele- ments toward the center. The dis- covery of SN 2021yfj provides direct evidence of long-hypothesized in- ternal layering in giant stars. It of- fers an unprecedented glimpse inside a stellar giant’s interior — captured just moments before its explosive death. “This event quite literally looks like nothing anyone has ever seen be- fore,” added Adam Miller, an assis- tant professor of physics and as- tronomy at Northwestern and sen-ior author on the study. “This star is telling us that our ideas and theo- ries for how stars evolve are too narrow. It’s not that our textbooks are incorrect, but they clearly do not fully capture everything pro- duced in nature. There must be more exotic pathways for a massive star to end its life that we hadn’t considered.” NOVEMBER-DECEMBER2025 T ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 41 ﻳﻮﺿــﺢ ــﺪﻳﻮ اﻧﻔﺠــﺎراﻟﻤﺴــﺘﻌﺮاﻷﻋﻈــﻢ ﻫــﺬا اﻟﻔ SN 2021y ـــﺎﻩ وﺗﺸــ ﻞ ﻘﺎ . [Keck Obs./Adam Makarenko] ﻳﻮﺿﺢ ﻟﻨﺎ ﻫﺬا اﻻﻛﺘﺸﺎف ﻛﻴﻒ ﺗﺘﺸﻜﻞ اﻟﻨﺠﻮم وﻳﺆﻛﺪ أن اﻟﻨﺠﻮم ﻗﺪ ﺗﻔﻘﺪ اﻟﻜﺜ ﻣﻦ ﻣﺎدﺗﻬـﺎ ﻗﺒﻞ أن ﺗﻨﻔ ﻓ. ﺠﺮ ﻼ ﻳﻘﺘﴫ اﻷﻣﺮ ﻋﲆ ﻓﻘـﺪان ا ﻟﻄﺒﻘﺎت اﻟﺨﺎرﺟﻴﺔ ﻓﺤﺴﺐ ﺑﻞ ﻳ أن ﻤﻜﻦ د ﺗﺠﺮ اﻟﻨﺠﻮم ﺑﺎﻟﻜﺎﻣﻞ ﺣﺘﻰ ﻧﻮاﺗﻬـﺎ ﻣـﻊ اﺳـﺘﻤﺮار إﻧﺘـﺎج اﻧﻔﺠـﺎر ﻣـﺬﻫﻞ ﻳﻤﻜﻨﻨـﺎ رﺻـﺪه ﻣـﻦ ﻣﺴﺎﻓﺎت ﺑﻌﻴﺪة ﺟﺪ . اً ﻋﻨـﺪﻣﺎ ﺗﻨﻔﺠـﺮ اﻟﻨﺠـﻮم اﻟﻀﺨﻤﺔ ﻋﺎدةً ﻳﺠﺪ ﻋﻠﻤﺎء اﻟﻔﻠﻚ دﻻﺋـﻞ ﻗﻮﻳـﺔ وﺟﻮد ﻋﲆ ﻋﻨﺎﴏ ﺧﻔﻴﻔﺔ ﻣﺜـﻞ اﻟﻬﻴـﺪروﺟ واﻟﻬ ﻠﻴﻮم ﻟﻜـﻦ ا ﺴـﺘﻌﺮ اﻷﻋﻈـﻢ ا ﻜﺘﺸـﻒ ﺴـﻤﻰ وا ﺣﺪﻳﺜﺎً SN2021yfj أﻇﻬـﺮ ﺑﺼـﻤﺔ ﻛﻴﻤﻴﺎﺋﻴـﺔ ﻣﺨﺘﻠﻔـﺔ وﻣ ﺬﻫﻠـﺔ ﺣﻴـﺚ اﺣﺘـﻮت ﻋﲆ ﻃﻴﻔﻴﺎً اﻟﺴﻴﻠﻜﻮن واﻟﻜﱪﻳﺖ واﻷرﺟﻮن ﻣﻤﺎ ﻳ ﺸ إﱃ أﻧـﻪ ﻓﻘـﺪ ﻃﺒﻘﺎﺗـﻪ اﻟﺨﺎرﺟﻴـﺔ ﻣـﻦ اﻟﻬﻴﺪروﺟ واﻟﻬﻠﻴﻮم واﻟﻜﺮﺑﻮن واﻷﻛﺴـﺠ واﻟﻨﻴﻮن وا ﻐﻨﻴﺴﻴﻮم ﻛﺎﺷﻔًﺎ ﻋـﻦ اﻟ ﺎت ﻄﺒﻘـ اﻟﺪاﺧﻠﻴﺔ اﻟﻐﻨﻴﺔ ﺑ ﺎﻟﺴـﻴﻠ و ﻜﻮن اﻟﻜﱪﻳـﺖ ﻗﺒـﻞ اﻻﻧﻔﺠﺎر ﻣﺒﺎﴍة . وﻗﺪ اﻗﱰح ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻣﻨﺬ ﻓـﱰة ﻃﻮﻳﻠـﺔ أن اﻟﻨﺠﻮم اﻟﻀ ﺨﻤﺔ ﺗﻤﺘﻠﻚ ﺑﻨﻴـﺔ ﻃﺒﻘﻴـﺔ ﺗﺸـﺒﻪ اﻟﺒﺼـﻞ ﺣﻴ ـﺚ ﺗﺘﻮاﺟـﺪ اﻟﻌﻨ ـﺎﴏ اﻷ ﰲ ﺧـﻒ اﻟﻄﺒ ﻘﺎت اﻟﺨﺎرﺟﻴﺔ ﺑﻴﻨﻤـﺎ ﺗﺼـﺒﺢ اﻟ ﻌﻨـﺎﴏ أﻷﺛﻘﻞ ﺗﺪرﻳﺠﻴ ﻧﺤﻮ ﺎً ا ﺮﻛﺰ . ﻳﻮﻓﺮ اﻛﺘﺸﺎف ا ﺴﺘﻌﺮ ا ﻷﻋﻈـﻢ SN 2021yfj دﻟﻴﻼً اً ﻣﺒﺎﴍ ﻋﲆ وﺟﻮد ﻃﺒﻘﺎت داﺧﻠﻴﺔ ﻛﺎﻧﺖ ﻣﻔﱰﺿﺔ ﻣﻨﺬ ﻓﱰة ﻃﻮﻳﻠﺔ ﰲ اﻟﻨﺠﻮم اﻟﻌﻤﻼﻗﺔ . إﻧﻪ ﻳﻤﻨﺤﻨﺎ ﺤﺔ ﻏ ﻣﺴﺒﻮﻗﺔ إﱃ ﺑﺎﻃﻦ ﻧﺠـﻢ ﻋﻤﻼق رﺻﺪه ﻗﺒﻞ ﻟﺤﻈﺎت ﻓﻘﻂ ﻣﻦ اﻧﻔﺠﺎره . وأﺿﺎف آدم ﻣﻴﻠﺮ اﻷﺳﺘﺎذ ا ﺴﺎﻋﺪ ﰲ اﻟﻔﻴﺰﻳـﺎء وﻋﻠﻢ اﻟﻔﻠﻚ ﺑ ﺠﺎﻣﻌﺔ ﻧﻮرث وﺳـﱰن وا ﺆﻟـﻒ اﻟﺮﺋﻴﴘ ﻟﻠﺪراﺳﺔ " : ﻳﺒﺪو ﻫﺬا اﻟﺤـﺪث ﺣﺮﻓﻴـ ﺎً ﻛﻤﺎ ﻟﻮ اﻧﻪ ﻻ ﻳﺸﺒﻪ أيﳾء رأﻳﻨـﺎه ﻣـﻦ ﻗﺒـﻞ ﺣﻴﺚ ﻳﺨﱪﻧﺎ ﻫﺬا اﻟﻨﺠﻢ أن أﻓﻜﺎرﻧﺎ وﻧﻈﺮﻳﺎﺗﻨﺎ ﺣﻮل ﻛﻴﻔﻴﺔ ﺗﻄـﻮر اﻟﻨﺠـﻮم ﺿـﻴﻘﺔ ﻟﻠﻐﺎﻳـﺔ . ﺖ ﻟﻴﺴ ﻛﺘﺒﻨﺎ ا ﺪرﺳﻴﺔ ﻬﺎ ﻟﻜﻨ ﺧﺎﻃﺌﺔ ﻻ ﺗﺼـﻮر ﻛﻞ ﻣﺎ ﻳﺤﺪث ﰲ اﻟﻄﺒﻴﻌﺔ ﺑﺸﻜﻞ ﻛﺎﻣﻞ أن ﻻ ﺑﺪ ﻫﻨﺎك ﻣﺴﺎرات أ ﻛﺜﺮ ﻏﺮاﺑﺔ ﻹﻧﻬﺎء ﺣﻴـﺎة ﻧﺠـﻢ ﺿﺨﻢ ﻟﻢ ﻧﻔﻜﺮ ﻓﻴﻬ ".ﺎ ﻳﻔﺘﺢ ﻫـﺬا اﻻﻛﺘﺸـﺎف اﻟﺒﺎب أﻣـﺎم إﻋـﺎدة اﻟﻨﻈـﺮ ﰲ ﻧﻤـﺎذج ﺗﻄـﻮر اﻟﻨﺠﻮم اﻟﻌﻤﻼﻗﺔ وﻧﻬﺎﻳﺎﺗﻬﺎ ﻣﻤﺎ ﻗـﺪ ﻳـﺆدي إﱃ ﺗﺤﺪﻳﺜﺎت ﺟﻮﻫﺮﻳﺔ ﰲ ﻓﻬﻤﻨﺎ ﻟﻠﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ . ﻛﻤﺎ ﻳﺸ إﱃ و ﺟﻮد ﺗﻨﻮع أﻛﱪ ﰲ ﻃﺮق ﻣـﻮت اﻟﻨﺠﻮم وﻳﺤﻔﺰ اﻟﻌﻠﻤﺎء ﻋﲆ اﻟﺒﺤﺚ ﻋﻦ أﺣﺪاث ﻣﺸﺎﺑﻬﺔ ﻟﻔﻬﻢ ﻫﺬا اﻟﺘﻨﻮع اﻟﻜﻮﻧﻲ اﻟﻜﺒ . ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 5