Free Astronomy Magazine September-October 2026 ARABIC VERSION

likely explanation is a tidal disrup- tion event, which happens when a star strays too close to a black hole andispulledapartbygravity.Inthis case, the fast rise in the optical brightness indicates an intermedi- ate-mass black hole, a long-sought class that falls between stellar-mass black holes formed by collapsing stars and the supermassive black holes found in the centers of galax- ies. These middleweight black holes have been difficult to find, and as- tronomers have been eager for new ways to identify them. AT2019ijn offers one such path: ifan intermediate-mass black hole launches a jet that is not aimed di- rectly at Earth, the event may look modest at first, then become dra- matically brighter in radio lightlater as the jet slows and its after-glow emission spreads into view. Thatdelayedbrighteningisoneof the most striking features of this discovery.At3gigahertz,theradio signal reached a luminosity more than 100 times brighter than radio emissionseenfromknownfastblue optical transients or supernovae at similar stages. To piece together the event, the teamcombinedopticalsurveydata with radio observations from the NSF VLA, including the Very Large Array Sky Survey, and additional measurements from ASKAP in Aus- tralia and the upgraded Giant Me- trewave Radio Telescope in India. That broad radio coverage let the researchers track how the signal changedovertimeandtestmodels for an expanding outflow powered by a tidal disruption event. Their modeling suggests the radio emis- sion came from material moving at asignificantfractionofthespeedof light.Thedataarebestexplainedby a narrow relativistic jet viewed from well off to the side, rather than head-on, which naturally accounts forwhytheradioflareappearedso late.Thisdiscoveryisespeciallysig- nificantbecauseitexpandstheway astronomers can search for hidden black holes and the extreme jets they launch. It also suggests that someunusualopticaltransientsmay bepartofabroaderfamilyofblack- hole-powered events that have been missed because their radio peaks arrive long after the initial flash.Asnewskysurveysrepeatedly scan the heavens in both visible light and radio waves, astronomers expect to find more events like AT2019ijn. Each new detection could help reveal how intermedi- ate-mass black holes form, how often they tear apart stars, and under what conditions they pro- ducepowerful jets.     SEPTEMBER-OCTOBER2026 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 27 رﺳـــﻢ ﺗﺨ ﻠــــﻲ ــــﺎم ﺛﻘــــﺐ أﺳــــﻮد ﻈﻬــــﺮآﺛــــﺎرﻗ ﻣﺘﻮﺳــﻂ اﻟ ـﺎﻟﻘﺮ ﻣﻨــﮫ ـﻢ ﻣــﺎرّ ﻜﺘﻠــﺔ ﺘﻤﺰ ــﻖ ﻧ إﻟــــــﻰ ﺗﺸــــــ ﻞ ﻗــــــﺮص ﺗــــــﺮا ﻢ و ﻣﻤــــــﺎ أد ﻧﻔﺎﺛــــــﺔ ﺿــــ ﻘﺔ ﻧﺴــــﺒ ﺔ ) أﻋﻠــــﻰ اﻟ (ﺴــــﺎر و ﺸــــ اﻟــــ ﻂ ﺨـ ــــــﺔ ﻣــــــﻦ اﻷرض اﻟﻤــــــﻨﻘﻂ إﻟــــــﻰﺧــــــﻂ اﻟﺮؤ وﻟــــــﻢ ﺼـﺒﺢ اﻟﺘــﻮﻫﺞ اﻟﻼﺣــﻖ ﻟﻠﻨـــ ﻔﺎﺛﺔ اﻟﻤﺮﺻــﻮد ﺧــﺎرج ـــــــــ ﻣﺤﻮرﻫـــــــــﺎ ﻣﺮ ﺎً إﻻ ﻌـــــــــﺪ أن ﺗﻤـــــــــﺪ د اﻻﻧ ﻌـــــــــﺎث اﻟﺮادﻳـﻮي ) أﺳــﻔﻞ اﻟ ( ﻤــ ﻟ ﺸـﻤﻞ ﺧــﻂ رؤ ﺘﻨـﺎ ــﺎد ﺳــﻄﻮع ﻫــﺬا اﻻﻧ ﻌــﺎث ﻣﻤـﺎ ﺗﺴــ ﺐ ﻓــﻲ ازد ﻌﺪﺳﻨﻮات ﻣﻦ وﻗﻮع اﻟ ـ ﺤﺪث اﻷﺻﻠﻲ . [NSF/AUI/NSF NRAO/M.Weiss] وﺧﻠــﺺ اﻟﺒ ـﺎﺣ ﺜﻮن إﱃ أن اﻟﺘﻔﺴـ اﻷﻛﺜ ـﺮ ﺗﺮﺟﻴﺤ ﺎً أﻧﻪ ﻫﻮ ﺣﺪث اﺿﻄﺮاب ﻣـﺪي وﻫـﻮ ﻳﺤﺪث ﻋﻨﺪﻣﺎ ﻳﻘﱰب ﻧﺠﻢ أﻛﺜﺮ ﻣﻦ اﻟﻼزم ﻣﻦ ﺛﻘﺐ أﺳﻮد ﻓﺘﻘﻮم ﺟﺎذﺑﻴﺘﻪ ﺑﺘﻤﺰﻳﻘﻪ وﰲ ﻫﺬه اﻟﺤﺎﻟﺔ ﻳﺸ اﻻرﺗﻔﺎع اﻟـ ـ ﴪﻳﻊ ﰲ اﻟﺴـﻄﻮع اﻟﺒﴫي إﱃ وﺟﻮد ﺛﻘﺐ أﺳﻮد ﻣﺘﻮﺳﻂ اﻟﻜﺘﻠﺔ وﻫﻲ ﻓﺌﺔ ﻃﺎل اﻟﺒﺤﺚ ﻋﻨﻬﺎ ﺗﻘﻊ ﺑ اﻟ ﺜﻘﻮب اﻟﺴﻮداء ذات اﻟﻜﺘﻠﺔ اﻟﻨﺠﻤﻴـﺔ اﻟﺘـﻲ ﺗﺘﺸـﻜﻞ ﻧﺘﻴﺠﺔ اﻧﻬﻴ ﺎر اﻟﻨﺠﻮم واﻟﺜﻘﻮب اﻟﺴﻮداء ﻓﺎﺋﻘﺔ اﻟﻜ ﺘﻠﺔ ا ﻮﺟﻮدة ﰲ ﻣﺮاﻛﺰ ا ﺠﺮات وﻗﺪ ﻇﻠـﺖ ﻫﺬه اﻟﺜﻘﻮب اﻟﺴﻮ داء ﻣﺘﻮﺳﻄﺔ اﻟﻜﺘﻠﺔ ﺻﻌﺒﺔ اﻻﻛﺘﺸﺎف وﻟﺬﻟﻚ ﺳﻌﻰ ﻋﻠﻤﺎء اﻟﻔﻠﻚ إﱃ إﻳﺠﺎد ﻃﺮق ﺟﺪﻳﺪة ﻟﻠﺘﻌﺮف ﻋﻠﻴﻬﺎ . ﻳﻘﺪم AT2019ijn أﺣﺪ ﻫﺬه اﻟﺴﺒﻞ ﻓﺈذا أﻃﻠﻖ ﺛﻘﺐ أﺳﻮد ﻣﺘﻮﺳﻂ اﻟﻜﺘﻠـﺔ ﻧﻔﺎﺛـﺔ ﻻ ﺗﺘﺠـﻪ ﻣﺒﺎﴍ ة ﻧﺤـﻮ اﻷرض ﻓﻘـﺪ ﻳﺒـﺪو اﻟﺤـﺪث ﰲ اﻟﺒﺪاﻳﺔ ﻣﺘﻮاﺿﻌًﺎ، ﺛﻢ ﻳﺰداد ﺳﻄﻮﻋﻪ ﺑﺼـﻮرة ﻛﺒ ة ﰲ ا ﻷﻃﻮال ا ﻮﺟﻴﺔ اﻟﺮادﻳﻮﻳﺔ ﻻﺣﻘﺎً ﻣﻊ ﺗﺒـﺎﻃﺆ اﻟﻨﻔﺎﺛـﺔ واﻧﺘﺸـﺎر اﻧﺒﻌـﺎث اﻟﺘـﻮﻫﺞ اﻟﻼﺣﻖ إﱃ ﻣﺠﺎل رؤﻳﺘﻨﺎ وﻳ ﻌـﺪ ﻫـﺬا اﻻزدﻳـﺎد ـــــــــــــــــــــــــــــــــــــ ا ﺘﺄﺧ ﺮ ﰲ اﻟﺴﻄﻮع أﺣﺪ أﻛﺜﺮ اﻟﺴـﻤﺎت ﻟﻔﺘـ ﺎً ﻟﻼﻧﺘﺒـﺎه ﰲ ﻫـﺬا اﻻﻛﺘﺸـﺎف . وﻋﻨــﺪ ﺗـﺮدد 3 ﺟﻴﺠﺎﻫﺮﺗﺰ ﺑﻠﻎ ﻌﺎن اﻹﺷﺎرة اﻟﺮادﻳﻮﻳﺔ أﻛﺜﺮ ﻣﻦ 100 ﺿﻌﻒ ﻌﺎن اﻻﻧﺒﻌﺎﺛـﺎت اﻟﺮادﻳﻮﻳـﺔ ا ﺮﺻﻮدة ﻣﻦ اﻟﻈـﻮاﻫﺮ اﻟﺒـ ـ ﴫﻳﺔ اﻟﺰرﻗـﺎء اﻟﴪﻳﻌﺔ اﻟﻌﺎﺑﺮة أو ا ﺴـﺘﻌﺮات اﻟﻌﻈﻤـﻰ ﰲ ﻣﺮاﺣﻞ ﻣﻤﺎﺛﻠﺔ . وﻹﻋﺎدة ﺑﻨـﺎء ﺗﻔﺎﺻـﻴﻞ ﻫـﺬا اﻟﺤـﺪث ﺟﻤـﻊ اﻟﻔﺮﻳﻖ ﺑـ ﺑﻴﺎﻧـﺎت ا ﺴـﻮﺣﺎت اﻟﺒﺼـ ﺮﻳﺔ ـ واﻷرﺻﺎد اﻟﺮادﻳﻮﻳﺔ اﻟﺘﻲ اﺟﺮﺗﻬـﺎ ﻣﺼـﻔﻮﻓﺔ ﻛﺎرل ﺟﻲ ﺟﺎﻧﺴﻜﻲ اﻟﻜﺒ ة اً ﺟﺪ ﺑﻤـﺎ ﰲ ذﻟـﻚ ا ﺴﺢ اﻟﺴﻤﺎ وي ﺑﺎﺳﺘﺨﺪام ا ﺼﻔﻮﻓﺔ اﻟﻜﺒ ة اً ﺟﺪ إﱃ ﺟﺎﻧﺐ ﻗﻴﺎﺳﺎت إﺿﺎﻓﻴﺔ ﻣﻦ ﻣﺼﻔﻮﻓﺔ اﻟﻜﻴﻠــﻮﻣﱰ ا ﺮﺑــﻊ اﻷﺳــﱰاﻟﻴﺔ اﻟﺘﻤﻬﻴﺪﻳــﺔ أﺳﻜﺎب ) ( ﰲ أﺳﱰاﻟﻴﺎ واﻟﺘﻠﺴـﻜﻮب اﻟﺮادﻳـﻮي اﻟﻌﻤﻼق ا ﻄﻮر ﻟﻠﻤﻮﺟـﺎت ا ﱰﻳـﺔ . ﰲ اﻟﻬﻨـﺪ وأﺗﺎﺣﺖ ﻫﺬه اﻟﺘﻐﻄﻴـﺔ اﻟﺮادﻳﻮﻳـﺔ اﻟﻮاﺳـﻌﺔ ﻟﻠﺒﺎﺣﺜ ﺗ ﺘﺒﻊ ﻛﻴﻔﻴﺔ ﺗﻐ اﻹﺷﺎرة ﻣﻊ اﻟﺰﻣﻦ واﺧﺘﺒﺎر ﻧﻤﺎذج ﻟﺘﺪﻓﻖ ﻣـﺎدي ﻳﺘﻤـﺪد ﻧﺘﻴﺠـﺔ ﺣﺪث اﺿﻄﺮاب ﻣﺪي وﺗﺸ ﻧﻤﺎذﺟﻬﻢ إﱃ أن ـــــــــــــــــــــــــــــــــــــ اﻻﻧﺒﻌﺎث اﻟﺮادﻳﻮي ﺻﺪر ﻋـﻦ ﻣـ ﺎدة ﺗﺘﺤـﺮك ﺑﴪﻋﺔ ﺗﻤﺜﻞ ﺟﺰءاً ﻣ اً ﻛﺒ ﻦ ﴎﻋـﺔ اﻟﻀـﻮ ء َ وﺗﻔﴪ اﻟﺒﻴﺎﻧﺎت ﻋـﲆ أﻓ ﻀـﻞ وﺟـﻪ ﺑﻮﺟـﻮد ﻧﻔﺎﺛﺔ ﺿﻴﻘﺔ ﻧﺴﺒﻴﺔ ﺗ ﺮﺻﺪ ﻣﻦ زاوﻳﺔ ﺟﺎﻧﺒﻴﺔ ﺑﻌﻴﺪة ﻋﻦ ﻣﺤﻮرﻫﺎ وﻟﻴﺲ ﻣﻦ اﺗﺠﺎه ﻣﻮاﺟـﻪ ﻟﻬﺎ، وﻫﻮ ﻣﺎ ﻳﻔﴪ ﺑﺼـﻮرة ﻃﺒﻴﻌﻴـﺔ ﺳـﺒﺐ ﻇﻬﻮر اﻻﻧﺪﻓﺎع اﻟﺮادﻳﻮي ﺑﻌﺪ وﻗﺖ ﻃﻮﻳﻞ ﻣﻦ اﻟﺤﺪث اﻷﺻﲇ . ﻳﻜﺘﺴﺐ ﻫﺬا اﻻﻛﺘﺸﺎف أﻫﻤﻴﺔ ﺧﺎﺻـﺔ ﻷﻧـﻪ ﻳﻮﺳﻊ اﻟﻄﺮق اﻟﺘﻲ ﻳﺴﺘﻄﻴﻊ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻣﻦ ﺧﻼﻟﻬﺎ اﻟﺒﺤﺚ ﻋﻦ اﻟﺜﻘﻮب اﻟﺴـﻮداء اﻟﺨﻔﻴـﺔ واﻟﻨﻔﺎﺛ ـﺎت اﻟﻌﻨﻴﻔ ـﺔ اﻟﺘ ـﻲ ﺗﻄﻠﻘﻬــﺎ وﻣ ـﻊ اﺳﺘﻤﺮار ا ﺴـﻮﺣﺎت اﻟﺴـﻤﺎوﻳﺔ اﻟﺠﺪﻳـﺪة ﰲ ﻣﺴﺢ اﻟﺴـﻤﺎء ﺑﺼـﻮرة ﻣﺘﻜـﺮرة، ﺳـﻮاء ﰲ اﻟﻀﻮء ا ﺮﺋﻲ أو ا ﻮﺟـ ﺎت اﻟﺮادﻳﻮﻳـﺔ ﻳﺘﻮﻗـﻊ اﻛﺘﺸﺎف ا ﺰﻳﺪ ﻣـﻦ اﻷﺣـﺪاث ا ﺸـﺎﺑﻬﺔ ﻟــ AT2019ijn وﻗﺪ ﻳﺴﻬﻢ ﻛﻞ اﻛﺘﺸـﺎف ﺟﺪﻳـﺪ ﰲ ﺗﻮﺿﻴﺢ ﻛﻴﻔﻴﺔ ﺗﺸـ ﻜﻞ اﻟﺜﻘـﻮب اﻟﺴـﻮداء ﻣﺘﻮﺳﻄﺔ اﻟﻜﺘﻠﺔ وﻋ ﺪد ا ﺮات اﻟﺘﻲ ﺗﻤﺰق ﻓﻴﻬﺎ اﻟﻨﺠﻮم وﻇﺮوف إﻃﻼق ﻧﻔﺎﺛﺎت ﻗﻮﻳﺔ . - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 6