Free Astronomy Magazine September-October 2024

“I Astronomers see a massive black hole awaken in real time byESO − BárbaraFerreira magine you’ve been ob- servingadistantgalaxyfor years,anditalwaysseemed calm and inactive,” says Paula Sánchez Sáez, an astronomer at ESO inGermanyandleadauthorofthe study published in Astronomy & Astrophysics . “Suddenly, its [core] startsshowingdramaticchangesin brightness,unlikeanytypicalevents we’ve seen before.” This is what happenedtoSDSS1335+0728,which is now classified as having an ‘active galactic nucleus’ (AGN) — a bright compactregionpoweredbyamas- siveblackhole—afteritbrightened dramatically in December 2019. Somephenomena,likesupernova explosionsortidaldisruptionevents — when a star gets too close to a black hole and is torn apart — can make galaxies suddenly light up. Butthesebrightnessvariationstyp- ically last only a few dozen or, at most, a few hundreds of days. SDSS1335+0728 is still growing brightertoday,morethanfouryears ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 20 ـــــﺎً ﻋﻠﻤـــــﺎء اﻟﻔﻠـــــﻚ ﻳﺮﺻـــــﺪون ﺛﻘ أﺳـــﻮد اً ﺿـــ ﻤﺎً ﺴـــﺘ ﻘﻆﻓـــﻲ اﻟﻮﻗﺖ اﻟﻔﻌﻠﻲ : ﻘﻠﻢ ﺎر ﺮا ﻓ ﺮا - اﻟﻤﺮﺻﺪ اﻷوروﺑﻲ اﻟـﺠﻨﻮﺑﻲ ﻗﺎﻟـﺖ ﺑﺎوﻻ ﺳﺎﻧﺸﻴﺰ ﺳﺎﻳﺰ ﻋﺎ ﺔ اﻟﻔﻠـﻚ ﰲ ا ﺮﺻﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ ﰲ أ ﺎﻧﻴﺎ وﻣﺆﻟﻔـﺔ اﻟﺪراﺳـﺔ ا ﻨﺸـﻮرة ﰲ ﻣﺠﻠــﺔ ﻋﻠـﻢ اﻟﻔﻠـﻚ واﻟﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ " : ﺗﺨﻴﻞ أﻧﻚ ﻛﻨﺖ ﺗﺮاﻗـﺐ ﻣﺠﺮة ﺑﻌﻴﺪة ﻟﺴﻨﻮات وﻛﺎﻧـﺖ ﺗﺒـﺪو داﺋﻤـﺎ ﻫﺎدﺋﺔ وﻏ ﻧﺸﻄﺔ " ﺛﻢ ﻓﺠﺄة ﺗ ﻧﻮاﺗﻬﺎ ] ﺒﺪأ [ ﰲ إﻇﻬﺎر ﺗﻐﻴ ات ﺟﺬرﻳﺔ وﻫـﺬا ﻣـﺎ ﺣـﺪث ﻟـ SDSS1335+0728 اﻟﺘﻲ ﺗـﻢ ﺗﺼـﻨﻴﻔﻬ ﺎ ــــ اﻵن ﻋﲆ أﻧﻬ ﺗ ﺎ ﺤﺘﻮي ﻋـﲆ » ﻧـﻮاة ﻣﺠﺮ ﺔ ﻳـ «ﻄﺔ ﻧﺸ وﻫـﻲ ﻣﻨﻄﻘـﺔ ﴩﻗﺔ ـﻣـ ﻣﻌﻘـﺪة ﻣﺪﻋﻮﻣﺔ ﺑﺜﻘﺐ أﺳﻮد ﺿﺨﻢ ﺑﻌﺪ أن ﺳﻄﻌ ﺖ ﺑﺸ ـﻜﻞ ﻛﺒــ ﰲ دﻳﺴ ـﻤﱪ 2019 . ﺑﻌ ـﺾ اﻟﻈﻮاﻫﺮ ﻣﺜﻞ اﻧﻔﺠﺎرات ا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ أو أﺣـﺪاث اﺿـﻄﺮاب ا ـﺪ واﻟﺠـﺰر ﻋﻨـﺪﻣﺎ ﻳﻘﱰب اﻟـﻨﺠﻢ ﻛﺜـ اً ﻣـﻦ اﻟﺜﻘـﺐ اﻷﺳـﻮد وﻳﺘﻤﺰق ﻳﻤﻜﻦ أن ﻳﺠﻌﻞ ا ﺠـﺮات ﺗـ ﴤء ـ ـــ . ﻓﺠﺄة ﻟﻜﻦ ﻣﺜﻞ ﻫﺬه اﻟﺘﻐـ ات ﰲ ﺳـﻄﻮع ا ﺠـﺮة وم ﻻ ﺗـﺪ ﰲ اﻟﻐﺎﻟ ـﺐ ﺳـﻮى ﺑﻀـﻊ ـﻋ ﴩات ﻣﻦ اﻷﻳـﺎم أو ﻋـﲆ اﻷﻛﺜـﺮ ﺑﻀـﻊ ﻣﺌﺎت ﻣﻦ اﻷﻳﺎم . ﺰال ﺗـﻻ ا ﺠـﺮة SDSS1335+0728 ﻨﻤـﻮ ﺗ ﺑﺸﻜﻞ أﻛﺜﺮ ﺳﻄﻮﻋﺎً ﺣﺘﻰ ﻳﻮﻣﻨﺎ ﻫـﺬا ﻋـﲆ اﻟﺮﻏﻢ ﻣﻦ ﻣﺮور أﻛﺜﺮ ﻣﻦ أرﺑﻊ ﺳﻨﻮات ﻣﻨـﺬ ﻧﺸﺎﻃﻬﺎ . ﻷول ﻣﺮة - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 4