Free Astronomy Magazine May-June 2025 ARABIC VERSION

Webb reveals rapid-fire light show from Sagittarius A* byNASA/ESA/CSA Amanda Morris ChristinePulliam he supermassive black hole at thecenteroftheMilkyWay appears to be having a party, completewithadiscoball- stylelightshow.UsingNASA’sJames Webb Space Telescope, a team ofastrophysicists has gained the longest, most detailed glimpse yetofthe“void”thatlurksinthemid- dleofour galaxy. They found that the swirling disk of gas and dust (or accretion disk) orbiting the central supermassive blackhole,calledSagittariusA*,is emittingaconstantstreamofflares withnoperiodsofrest.Thelevelof activityoccursoverawiderangeof time — from short interludes to long stretches. While some flares arefaintflickers,lastingmeresec- onds, other flares are blindingly brighteruptions,whichspewdaily. Therealsoareevenfainterchanges that surge over months. The new findings could help physi- cists better understand the funda- mental nature of black holes, how theygetfedfromtheirsurrounding environments,andthedynamicsandev olutionofourowngalaxy. “Inourdata,wesawconstantly changing,bubblingbrightness,” said Farhad Yusef-Zadeh of North- western University in Illinois, wholed the study. “And then boom! Abigburstofbrightnesssuddenlypopp ed up. Then, it calmed downagain. We couldn’t find a pattern in this activity. It appears to be ran- dom.Theactivityprofileofthis blackholewasnewandexciting every time that we looked at it.” MAY-JUNE2025 T ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 10 و ﺐ ﻜﺸﻒﻋﺮﺿ ﺎً ﺎً ﺿﻮﺋ ﺮ ﻌًﺎ ﺳ ﻣﻦ * ﺳﺎﺟ ﺘﺎر ﻮس A : ﻘﻠﻢ ﺑﻮﻟ ﺎم أﻣﺎﻧﺪا ﻣﻮرﺲوﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ ﻳ ﺪو أن اﻟﺜﻘﺐ اﻷﺳﻮد ﻓﺎﺋﻖ اﻟﻜﺘﻠﺔ ﰲ ﻣ ﺮﻛﺰ ﻣﺠﺮة درب اﻟﺘﺒﺎﻧﺔ ﻳُﻈﻬﺮ ﻧﺸﺎﻃ ﺎَ ﻮﻣـﺎَ ﻣﺤﻤ ﺎَ ﻣﺼﺤﻮﺑ ﺑﻌﺮضﺿﻮﺋﻲ أﺷﺒﻪ ﺑﻜﺮ ة ﺗﻌﻜﺲ اﻟﻀﻮء ﰲ اﺗﺠﺎﻫـﺎت ﻣُﺨﺘﻠﻔـﺔ . ﺑﺎﺳـﺘﺨﺪام ﺗﻠﺴﻜﻮ ب ﺟـﻴﻤﺲ وﻳـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟ ﻮﻛﺎﻟـﺔ ﻧﺎﺳـﺎ ﺣﺼـﻞ ﻓﺮﻳــﻖ ﻣـﻦ ﻋﻠﻤــﺎء اﻟﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ ﻋﲆ أﻃـﻮل وأﻛﺜـﺮ ﻧﻈـﺮة ﺗﻔﺼـﻴﻠﻴﺔ ﺣﺘـﻰ اﻵن ﻋـﲆ اﻟﺜﻘـﺐ اﻷﺳــﻮد اﻟﻜﺎﻣﻦ ﰲ وﺳﻂ . ﻣﺠﺮﺗﻨﺎ وﺟﺪوا أن اﻟﻘﺮص اﻟﺪوا ر ز ﻣﻦ اﻟﻐﺎ واﻟﻐﺒـﺎر )أو ﻗﺮص اﻟﱰاﻛﻢ ( اﻟﺬي ﻳﺪور ﺣـﻮل ا ﻟﺜﻘـﺐ اﻷﺳـﻮد ﻓــﺎﺋﻖ اﻟﻜﺘﻠ ـﺔ ا ﺮﻛــﺰي ا ﺴـﻤﻰ ـــــــ - اﻟﻘــﻮس أ * ﻳ ﺼــﺪر دﻓﻘًــﺎ ﻣﺴــﺘﻤﺮًا ﻣــﻦ اﻟﺘﻮﻫﺠـﺎت دون ﻓـﱰات ﺳـﻜﻮن وﻳﺤـﺪث ﻣﺴﺘﻮى اﻟﻨﺸﺎط ﻋﲆ ﻣﺪى واﺳﻊ ﻣﻦ اﻟﻮﻗﺖ ﻣﻦ ﻓﱰات ﻗﺼ ة إﱃ ﻓﱰات . ﻃﻮﻳﻠﺔ ﺑﻴﻨﻤﺎ ﺑﻌﺾ اﻟ ﺘﻮﻫﺠـﺎت وﻣﻀـﺎت ﺧﺎﻓﺘـﺔ ﺗﺴﺘﻤﺮ ﻟﺜﻮان ٍﻣﻌﺪودة ﻓﺈن ﺗﻮﻫﺠﺎت أﺧـﺮى ﺗﻜﻮن اﻧﻔﺠﺎرات ﺳـﺎﻃﻌﺔ ﻟﻠﻐﺎﻳـﺔ ﺗﺤـﺪث ﺎً ﻳﻮﻣﻴ وﻫﻨﺎك أﻳﻀًـﺎ ﺗﻐـ ات أﻛﺜـﺮ ﺧﻔﻮﺗًـﺎ ﺗﺤﺪث ﻋﲆ ﻣﺪى أﺷﻬﺮ . ﻗﺪ ﺗﺴﺎﻋﺪ اﻟﻨﺘﺎﺋﺞ اﻟﺠﺪﻳﺪة اﻟﻔﻴﺰﻳﺎﺋﻴ ﻋﲆ ﻓﻬﻢ أﻓﻀـﻞ ﻟﻠﻄﺒﻴﻌـﺔ اﻷﺳﺎﺳـﻴﺔ ﻟﻠﺜﻘـﻮب اﻟﺴﻮداء وﻛﻴﻒ ﺗﺘﻐﺬى ﻣﻦ ﺑﻴﺌﺎﺗﻬﺎ ا ﺤﻴﻄـ ﺔ ودﻳﻨﺎﻣﻴﻜﻴﺎت وﺗﻄﻮر ﻣﺠﺮﺗﻨﺎ درب اﻟﺘﺒﺎﻧﻪ . ﻗﺎل ﻓﺮﻫﺎد ﻳﻮﺳﻒ زاد ه وﻫﻮ ﻋﺎﻟﻢ ﺑﺎرز ﻣﻦ ﺟﺎﻣﻌﺔ ﻧﻮرث وﺳﱰن ﰲ إﻟﻴﻨﻮي ﻗﺎﺋﺪ و ﻫـﺬه اﻟﺪراﺳﺔ ﻣﻮﺿﺤ : "ﺎ ﻟﻘـﺪ رأﻳﻨـﺎ ﺑﻮﺿـﻮح ﰲ ﺑﻴﺎﻧﺎﺗﻨﺎ ﺳﻄﻮﻋ ﺎً اً ﻣﺘﻐ ﺎً وﻓﻘﺎﻋﻴ ﺑﺎﺳـﺘﻤﺮار ﻓﺠﺄة ﻇﻬﺮت دﻓﻌﺔ ﻛﺒ ة ﻣﻦ اﻟﺴﻄﻮع ﺛـﻢ ﻫﺪأ اﻟﻮ . ﺿﻊ ﻣﺮة أﺧﺮى ﻟﻢ ﻧـﺘﻤﻜﻦ ﻣـﻦ اﻟﻌﺜـﻮر ﻋـﲆ ﻧ ﻤـﻂ ﻟﻬـﺬا اﻟﻨﺸﺎط اﻟﺬي ﻳﺒﺪو ﻋﺸﻮاﺋﻴ ﺎً . ﺗﻤﺎﻣﺎً ﻟﻘﺪ ﻛﺎﻧﺖ ﻃ ﺒﻴﻌﺔ ﻧﺸﺎط ﻫﺬا اﻟﺜﻘﺐ اﻷﺳﻮد ﺎً داﺋﻤ ﺟﺪﻳﺪة وﻣﺜ ة ﻟﻠﻐﺎﻳﺔ ﺑﺸﻜﻞ ﻻ ﻳﺼﺪق ﰲ ﻛﻞ ﻣﺮة ﻧﻈﺮﻧﺎ إﻟﻴﻪ . ﻣﺎﻳﻮ - ﻳﻮﻧﻴﻮ 2 0 2 5