Free Astronomy Magazine July-August 2023 ARABIC VERSION

would also need to explode as an ultra-stripped supernova so the two neutron stars could eventually col- lide and merge.” As well as representing the discovery of an incredibly rare cosmic oddity, finding and studying kilonova pro- genitor systems such as this can help astronomers unravel the mystery of how kilonovae form, shedding light on the origin of the heaviest ele- ments in the Universe. “For quite some time, astronomers speculated about the exact condi- tions that could eventually lead to a kilonova,” said NOIRLab astronomer and co-author André-Nicolas Chené. “These new results demonstrate that, in at least some cases, two sib- ling neutron stars can merge when one of them was created without a classical supernova explosion.” Producing such an unusual system, however, is a long and unlikely process. “We know that the Milky Way contains at least 100 billion stars and likely hundreds of billions more. This remarkable binary system is essentially a one-in-ten-billion sys- tem,” said Chené. “Prior to our study, the estimate was that only one or two such systems should exist in a spiral galaxy like the Milky Way.” Though this system has all the right stuff to eventually form a kilonova, it will be up to future astronomers to study that event. It will take at least one million years for the mas- sive star to end its life as a titanic su- pernova explosion and leave behind a second neutron star. This new stel- lar remnant and the pre-existing neutron star will then need to grad- ually draw together in a cosmic bal- let, slowly losing their orbital energy as gravitational radiation. When they eventually merge, the re- sulting kilonova explosion will pro- duce much more powerful gravitational waves and leave be- hind in its wake a large amount of heavy elements, including silver and gold. “This system reveals that some neu- tron stars are formed with only a small supernova kick,” concluded Richardson. “As we understand the growing population of systems like CPD-29 2176 we will gain insight into how calm some stellar deaths may be and if these stars can die without traditional supernovae.”     ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 50 ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 3 اﻟﻨﺠﻢ اﻵﺧﺮ أﻳﻀًﺎ إﱃ اﻻﻧﻔﺠـﺎر ﻋـﲆ ﺷـﻜﻞ ﻣﺴﺘﻌﺮ أﻋﻈﻢ ﻓﺎﺋﻖ اﻟﺘﺠﺮﻳـﺪ ﺣﺘـ ﻰ ﻳـﺘﻤﻜﻦ اﻟﻨﺠﻤﺎن اﻟﻨﻴﻮﺗﺮوﻧﻴﺎن ﰲ اﻟﻨﻬﺎﻳﺔ ﻣﻦ اﻻﻟﺘﺤﺎم واﻻﻧﺪﻣﺎج ﺑﺎﻹﺿﺎﻓﺔ إﱃ اﻧـﻪ ﻳﻤﺜـﻞ ًاﻛﺘﺸـﺎف ﻳﺒـﺎً ﻏﺮ ﻛﻮﻧﻴﺎ اً ﻧـﺎدر ﺑﺸـﻜﻞ اﺳـﺘﺜﺎﺋﻲ ، ﻓـﺈن اﻟﻌﺜ ـﻮر ﻋ ـﲆ أﻧﻈﻤ ـﺔ أﺳـﻼف اﻟ ﻜﻴﻠﻮﻧﻮﻓ ـﺎ ودراﺳﺘﻬﺎ ﻳﻤﻜﻦ أن ﻳﺴﺎﻋﺪ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ ﰲ ﻛﺸﻒ ﻟﻐﺰ ﻛﻴﻔﻴﺔ ﺗﺸﻜﻞ اﻟﻜﻴﻠﻮﻧﻮﻓﺎ وإﻟﻘـﺎء اﻟﻀﻮء ﻋﲆ أﺻﻞ أﺛ ﻘﻞ اﻟﻌﻨﺎﴏﰲ اﻟﻜﻮن . ﻗﺎل ﻋﺎﻟﻢ اﻟﻔﻠﻚ ﻣـﻦ ﻣﺨﺘـﱪ ﻧـﻮﻳﺮﻻب وا ﺆﻟـﻒ ا ﺸـﺎرك أﻧﺪرﻳـﻪ ﻧﻴﻜـﻮﻻ ﺗﺸـﻴﻨﻲ " : ﻟــﺒﻌﺾ اﻟﻮﻗﺖ ﺗﻮﻗﻊ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ ﺣـﻮل اﻟﻈـﺮوف اﻟﺪﻗﻴﻘﺔ اﻟﺘﻲ ﻳﻤﻜﻦ أن ﺗـﺆدي ﰲ اﻟﻨﻬﺎﻳـﺔ إﱃ اﻟ وﺟﻮد ﻜﻴﻠﻮﻧﻮﻓـﺎ ." ﺗﻮﺿـﺢ ﻫـﺬه اﻟﻨﺘـﺎﺋﺞ اﻟﺠﺪﻳﺪة أﻧﻪ ﰲ ﺑﻌـﺾ اﻟﺤـﺎﻻت ﻋـﲆ اﻷﻗـﻞ ﻳﻤﻜﻦ أن ﻳﻨﺪﻣﺞ ﻧﺠﻤﺎن ﻧﻴﻮﺗﺮوﻧﻴﺎن ﺷﻘﻴﻘﺎن ﻋﻨﺪﻣﺎ ﺗـﻢ ﺗﺸـﻜﻞ أﺣـﺪﻫﻤﺎ ﺑـﺪون اﻧﻔﺠـﺎر ﻣﺴﺘﻌﺮ أﻋﻈﻢ ﻛﻼﺳﻴﻜﻲ وﻣﻊ ذﻟﻚ ﻓﺈن إﻧﺘﺎج ﻣﺜﻞ ﻫﺬا اﻟﻨﻈـﺎم ﻏـ اﻟﻌـﺎدي ﻫـﻮ ﻋﻤﻠﻴـﺔ ﻃﻮﻳﻠﺔ وﻏ ﻣﺮﺟﺤﺔ " . ﻧﺤﻦ ﻧﻌﻠﻢ أن ﻣﺠﺮة درب اﻟﺘﺒﺎﻧ ﺔ ﺗﺤﺘﻮي ﻋﲆ ﻣﺎ ﻻ ﻳﻘﻞ ﻋـ ﻦ 100 ﻣﻠﻴﺎر ﻧﺠﻢ ورﺑﻤﺎ ﻣﺌﺎت ا ﻠﻴﺎرات أﺧﺮى . ﻗﺎل ﺗﺸﻴﻨﻲ : ﻫﺬا اﻟﻨﻈﺎم اﻟﺜﻨـﺎﺋﻲ اﻟﺮاﺋـﻊ ﻫـﻮ ﰲ اﻷﺳ ﺎس ﻧﻈﺎم واﺣﺪ ﻣﻦ ﻋ ـ . " ﴩة ﻣﻠﻴـﺎرات ﺑ ﺎﻟﺮﻏﻢ ﻣﻦ أن ﻫﺬا اﻟﻨﻈﺎم ﻳﺤﺘﻮي ﻋﲆ ﺟﻤﻴﻊ اﻟﻌﻨﺎﴏ اﻟﺼﺤﻴﺤﺔ ﻟﺘﺸـﻜﻴﻞ اﻟ ﻜﻴﻠﻮﻧﻮﻓـﺎ ﰲ اﻟﻨﻬﺎﻳ ﺔ إﻻ أن دراﺳـﺔ ﻫـﺬا اﻟﺤـﺪث ﻣـﱰوك ﻟﻌﻠﻤﺎء اﻟﻔﻠﻚ ا ﺴﺘﻘﺒﻠ . ﻴ ﺳﻴﺴﺘﻐﺮق اﻟﻨﺠﻢ اﻟﻬﺎﺋﻞ ﻣﺎ ﻻ ﻳﻘﻞ ﻋـﻦ ﻣﻠﻴـﻮن ﺳـﻨﺔ ﻟﻴﻨﻬـﻲ ﺣﻴﺎﺗﻪ ﻋﲆ ﺷﻜﻞ اﻧﻔﺠﺎر ﺳـﻮﺑﺮﻧﻮﻓﺎ ﻋﻤـﻼق وﻳﱰك وراءه ﻧﺠﻤًﺎ ﻧﻴﻮﺗﺮوﻧﻴًﺎ ﺛﺎﻧﻴًﺎ . ﺑﻌﺪ ذﻟـﻚ ﺳـﺘﺤﺘﺎج ﻫـﺬه اﻟﺒﻘﺎﻳـﺎ اﻟﻨﺠﻤﻴـﺔ اﻟﺠﺪﻳـﺪة واﻟــﻨﺠﻢ اﻟﻨﻴــﻮﺗﺮوﻧﻲ ا ﻮﺟــﻮد ﻣﺴــﺒﻘًﺎ إﱃ ًواﻟــﻨﺠﻢ اﻟﻨﻴــﻮﺗﺮوﻧﻲ ا ﻮﺟــﻮد ﻣﺴــﺒﻘًﺎ إﱃ اﻻﻟﺘﻔﺎف ﺗﺪرﻳﺠﻴ ﺎ ﰲ ﻣﻮازﻳﻦ ﻛﻮﻧﻴﺔ ﻣﻤﺎ ﻳﻔﻘﺪ ﺑـﺒﻂء ﻃﺎﻗﺘﻬﻤـﺎ ا ﺪارﻳـﺔ ﻛﺈﺷـﻌﺎع ﺛﻘـﺎ . ﱄ ﻋﻨـﺪﻣﺎ ﻳﻨـﺪﻣﺠﺎن ﰲ اﻟﻨﻬﺎﻳـﺔ ﻓـﺈن اﻧﻔﺠـﺎر اﻟﻜﻴﻠﻮﻧﻮﻓﺎ اﻟﻨﺎﺗﺞ ﺳـﻴﻮﻟﺪ ﻣﻮﺟـﺎت ﺟﺎذﺑﻴـﺔ أﻗﻮى ﺑﻜﺜ وﻳﱰك وراءه ﻛﻤﻴـﺔ ﻛﺒـ ة ﻣـﻦ اﻟﻌﻨﺎﴏ اﻟﺜﻘﻴﻠﺔ ﺑﻤﺎ ﰲ ذﻟﻚ اﻟﻔﻀﺔ واﻟﺬﻫﺐ . ﺧﻠـﺺ رﻳﺘﺸﺎردﺳــﻮن إﱃ أن ﻫـﺬا اﻟﻨﻈـﺎم ﻳﻜﺸﻒ أن ﺑﻌﺾ اﻟﻨﺠﻮم اﻟﻨﻴﻮﺗﺮوﻧﻴﺔ ﺗﺘﺸﻜﻞ ﻓﻘﻂ ﻣﻦ رﻛﻠﺔ ﺻﻐ ة ﻣﻦ ﻣﺴﺘﻌﺮ أﻋﻈﻢ . ﻧﻈـﺮًا ﻷ ﻧﻨـﺎ ﻧﻔﻬـﻢ اﻟﻌـﺪد ا ﺘﺰاﻳـﺪ ﻷﻧﻈﻤـﺔ اﺳــﺘﺜﻨﺎﺋﻴﺔ ﻣﺜــﻞ CPD-29 2176 ﻓﺴــﻮف ﻧﻜﺘﺴﺐ ﻧﻈﺮة ﺛﺎﻗﺒﺔ ﺣﻮل ﻣﺪى ﻫﺪوء ﺑﻌـﺾ ﻧﻬﺎﻳﺎت اﻟﻨﺠﻮم و ﻣﺎ إذا ﻛﺎﻧـﺖ ﻫـﺬه اﻟﻨﺠـﻮم ﻳﻤﻜ ـﻦ أن ﺗﻨﺘﻬ ـﻲ ﺣﻴﺎﺗﻬ ـﺎ ﺑ ـﺪون ﺣ ـﺪوث ﻣﺴﺘﻌﺮات ﻋﻈﻤﻰ ﺗﻘﻠﻴﺪﻳﺔ . ﻳﻮﺿـــﺢ ﻫـــﺬا اﻟﺮﺳـــﻢ ا ـــﺎﻧﻲ ﺗﻄـــﻮرﻧﻈـــﺎم اﻟﻨﺠـــﻮم ﻟﺒ CPD-29 2176 أولﺳــﻠﻒﻣﺆﻛـﺪ ﻟﻠﻜ ﻠﻮﻧﻮﻓـﺎ . ﻓــﻲ اﻟﻤﺮﺣﻠـﺔ 1 ــﻮن ﻧ ﻤــﺎن أزرﻗـﺎن ﺿــ ﻤﺎن ﺘ ﻓــﻲ ﻧﻈــﺎم ﻧ ﻤــﻲ ﺛﻨـــﺎﺋﻲ . اﻟﻤﺮﺣﻠـــﺔ 2 ﻣـــﻦ ﻘـــ أﻛـــ اﻟﻨ ﻤـــ ﻧ ــﺔ ﺣ ﺎﺗــﮫ ﻬﺎ . ﻓــﻲ اﻟﻤﺮﺣﻠــﺔ 3 ﻘــﻮم اﻟــﻨ ﻢ اﻷﺻــﻐﺮ ﺴـﺤﺐ اﻟﻤـﻮاد ﻣــﻦ رﻓ ﻘـﮫ اﻷﻛـ واﻷﻛــ ﻧﻀـﺠًﺎ ﻣﻤـﺎ إﻟــﻰ ﺗﺠﺮ ــﺪﻩ ﻳــﺆد ﻣـــﻦ اﻟﻐــﻼف اﻟــ ـ ـ ﺠﻮي اﻟـــ . ﺨﺎرﺟﻲ ﻓﻲ اﻟﻤﺮﺣﻠﺔ 4 ﺸ ﻞ اﻟـﻨ ﻢ اﻷﻛـ ﻣﺴـﺘﻌﺮًا أﻋﻈـﻢ ﻓــ ــﺔ ﻋﻤــﺮ ﺎﺋﻖ اﻟﺘﺠﺮ ــﺪ وﻫـﻮ اﻧﻔﺠــﺎرﻧﻬﺎ ﻢ أﻗـﻞ ﻣــﻦ ﻣﺴﺘﻌﺮ أﻋﻈﻢ ﻋﺎد . اﻟﻤﺮﺣﻠﺔ 5 ﻤـﺎ ﻻﺣـﻆﻋﻠﻤـﺎء ًـــــــﺎ اﻟﻔﻠــــــﻚﺣﺎﻟ ــــــﺪأ اﻟـــــــﻨ ﻢ اﻟﻨﻴــــــﻮﺗﺮوﻧﻲ اﻟﻨـــــــﺎﺗﺞ ﻣـــــــﻦ ﻳ اﻟﻤﺴــﺘﻌﺮاﻷﻋﻈــﻢ اﻟﺴــﺎﺑﻖ ﻓـــﻲﺳــﺤﺐ اﻟﻤــﻮاد ﻣـــﻦ رﻓ ﻘــﮫ ﻣﻤــﺎ ﻳــﺆد إﻟــﻰﻗﻠــﺐ اﻟﻄﺎوﻟــﺔ ﻋﻠــﻰ اﻟــﺰوج اﻟﺜﻨـــــــﺎﺋﻲ . اﻟﻤﺮﺣﻠـــــــﺔ 6 ﻣـــــــﻊ ﻓﻘـــــــﺪان ﺟـــــــﺰء ﻛﺒـــــــ ﻣـــــــﻦ اﻟﻐـــﻼف ـ اﻟـــ ﺠﻮي اﻟــــﺨﺎرﺟﻲ ﻓـــﺈن اﻟـــﻨ ﻢ اﻟﻤﺮاﻓـــﻖ ﻟـــﮫ أ ﻀًـــﺎ ﻣﺴـــﺘﻌﺮأﻋﻈـــﻢ ﻓـــﺎﺋﻖ اﻟﺘﺠﺮ ـــﺪ . ﺳـــﺘﺤﺪثﻫـــﺬﻩ اﻟﻤﺮﺣﻠﺔ ﻓﻲﺣﻮاﻟﻲﻣﻠﻴﻮنﺳﻨﺔ . اﻟﻤﺮﺣﻠﺔ 7 ﺛﻨﺎﺋﻲ ــــﺎدل ﻗﺮ ـــــﺐ ــــﺔ ﻓـــــﻲ ﻣــــﺪارﻣﺘ ﻣــــﻦ اﻟﻨﺠــــﻮم اﻟﻨﻴﻮﺗﺮوﻧ ـــــﺎن ـــــﺚ ﻳ ﻘـــــﻰ اﻵن ﺣ ﻫﻨـــــﺎك ﻧ ﻤـــــﺎن ﻫـــــﺎﺋﻼن . ﻓـــــﻲ اﻟﻤﺮﺣﻠــﺔ اﻟﺜﺎﻣﻨــﺔ ﺘﺼــﺎدم اﻟﻨ ﻤـﺎ ــﺎن ﻣــﻊ ن اﻟﻨﻴﻮﺗﺮوﻧ ﻌﻀﻬﻤﺎ و ﺘﺨﻠ ﺎن ﻋﻦ ﻃﺎﻗﺘﻬﻤـﺎ اﻟﻤﺪار ـ ﺔ ﺈﺷـﻌﺎع ﺛﻘﺎﻟﻲﺧﺎﻓﺖ . اﻟﻤﺮﺣﻠﺔ 9 اﻟﻤﺮﺣﻠﺔ اﻷﺧ ة ﻣﻦ ﻫﺬا اﻟﻨﻈﺎم ﺣ ﺚ ﻣﻤـﺎ اﻟﻨﻴـﻮﺗﺮوﻧﻴ ـﻼ اﻟﻨ ﻤـ ﺼﻄﺪم ًـﺎ ﻨﺘﺞ ﻛ ﻠﻮﻧﻮﻓـﺎ ﻗﻮ ـﻮﻧﻲ ﻟﻠﻌﻨﺎﺻـﺮ وﻫـﻮ اﻟﻤﺼـﻨﻊ اﻟ اﻟﺜﻘ ﻠ ﺔ ﻓﻲ ﻮﻧﻨﺎ . [CTIO/NOIRLab/NSF/AURA/P. Marenfeld]