Free Astronomy Magazine March-April 2023 ARABIC VERSION

B Black hole devours bypassing star by NASA/ESA − Ann Jenkins lack holes are gatherers, not hunters. They lie in wait until a hapless star wanders by. When the star gets close enough, the black hole’s gravitational grasp violently rips it apart and sloppily devours its gasses while belching out intense radiation. Astronomers using NASA’s Hubble Space Tele- scope have recorded a star’s final moments in detail as it gets gobbled up by a black hole. These are termed “tidal disruption events.” But the wording belies the complex, raw violence of a black hole encounter. There is a balance between the black hole’s gravity pulling in star stuff, and radiation blowing material out. In other words, black holes are messy eaters. Astronomers are using Hubble to find out the details of what happens when a wayward star plunges into the gravitational abyss. Hubble can’t photograph the AT- 2022dsb tidal event’s mayhem up close, since the munched-up star is nearly 300 million light-years away at the core of the galaxy ESO 583- G004. But astronomers used Hub- ble’s powerful ultraviolet sensitivity to study the light from the shredded star, which include hydrogen, car- bon, and more. The spectroscopy provides forensic clues to the black hole homicide. About 100 tidal disruption events around black holes have been de- ﻣﺠﻠﺔ Astronomy ﺎﻟﻌﺮ ﺔ ٢٢ ﺛﻘﺐ أﺳﻮد ﻠﺘﻬﻢ ﻧ ﻤﺎً ﻋﺎﺑﺮاً : ﻘﻠﻢ آن ﺟﻨﻜ - و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ ا ﻻ اﻟﺜﻘﻮب اﻟﺴﻮداء ﻛﺠﺎﻣﻊ ﻟﻠﻄﺮاﺋـﺪ وﻟﻴﺴﺖ ﻓﻬﻲ ،ﺼﻴﺎد ﻛﺎﻟ ﺗﻨﺘﻈﺮ ﺣﺘﻰ ﻳﻤﺮ ﻧﺠﻢ ﺳﻴﺊ اﻟﺤﻆ ﻋﻨﺪﻣﺎ ﻳﻘﱰب اﻟـﻨﺠﻢ ﺑﻤـﺎ ﻓﻴـﻪ اﻟﻜﻔﺎﻳﺔ ، ﻓﺈن ﻗﺒﻀﺔ اﻟﺜﻘﺐ اﻷﺳﻮد اﻟ ﺘ ﺜﻘـﺎﱄ ﺗﻤﺰﻗﻪ ﺑﻌﻨﻒ وﺗﻠﺘﻬﻢ ﻏﺎزاﺗﻪ ﺑﺸﻜﻞ ﻗﺬر ﺑﻴﻨﻤﺎ ﻳﻨﺒﻌﺚ ﻣﻨﻪ إﺷﻌﺎع ﺷﺪﻳﺪ . ﺳـﺠﻞ ﻋﻠﻤ ـﺎء اﻟﻔﻠ ـﻚ اﻟ ـﺬﻳﻦ ﻳﺴـﺘﺨﺪﻣ ﻮن ﺗ ﻠﺴﻜﻮب ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟ ﻮﻛﺎﻟﺔ ﻧ ﺎﺳﺎ اﻟﻠﺤﻈﺎت اﻷﺧ ة ﻟﻠـﻨﺠﻢ ﺑﺎﻟﺘﻔﺼـﻴﻞ ﻋﻨـﺪﻣﺎ ﻳﻠﺘﻬﻤﻪ ﺛﻘﺐ أﺳـﻮد ﻫـﺬه ﺗﺴـﻤﻰ " أﺣـﺪاث اﺿﻄﺮاب ا ﺪ واﻟﺠﺰر ". ﻟﻜﻦ اﻟﺼﻴﺎﻏﺔ ﺗﺘﻨﺎﻗﺾ ﻣـﻊ اﻟﻌﻨـﻒ ا ﻌﻘـﺪ اﻟﺨﺎم ﻮاﺟﻬﺎت اﻟﺜﻘﺐ اﻷﺳﻮد . ﻫﻨﺎك ﺗـﻮازن ﺑ ﺳﺤﺐ ﺟﺎذﺑﻴﺔ اﻟﺜﻘـﺐ اﻷﺳـﻮد ﻟﻸﺷـﻴﺎء اﻟﻨﺠﻤﻴﺔ واﻹﺷﻌﺎع اﻟﺬي ﻳﻨﻔﺚ ا ﻮاد . ﺑﻌﺒـﺎرة أﺧﺮى ، اﻟﺜﻘـﻮب اﻟﺴـﻮداء أﻛﻠـﺔ ﻓﻮﺿـﻮﻳﺔ . ﻳﺴﺘﺨﺪم ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻫﺎﺑﻞ ﻌﺮﻓﺔ ﺗﻔﺎﺻـﻴﻞ ﻣﺎ ﻳﺤﺪث ﻋﻨﺪﻣﺎ ﻳﻐﺮق ﻧﺠﻢ ﺿـﺎل ﰲ ﻫﺎوﻳـﺔ اﻟﺠﺎذﺑﻴﺔ ، ﻻ ﻳﺴﺘﻄﻴﻊ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ ﺗﺼﻮﻳﺮ ﻓﻮﴇﺣﺪث ا ﺪ واﻟﺠﺰر AT-2022dsb ﻋـﻦ ﻗﺮب ، ﺣﻴﺚ ﻳﺒﻌﺪ اﻟﻨﺠﻢ ا ﻤﻀﻮغ ﻣﺎ ﻳﻘـﺮب ﻣﻦ ٣٠٠ ﻣﻠﻴﻮ ن ﺳﻨﺔ ﺿﻮﺋﻴﺔ ﰲ ﻗﻠﺐ ا ﺠـﺮة ESO 583- G004 . ﻟﻜﻦ ﻋﻠﻤﺎء اﻟﻔﻠﻚ اﺳﺘﺨﺪﻣﻮا ﺣﺴﺎﺳﻴﺔ ﻫﺎﺑﻞ اﻟﻘﻮﻳﺔ ﻟﻸﺷﻌﺔ ﻓـﻮق اﻟﺒﻨﻔﺴـﺠﻴﺔ ﻟﺪراﺳـﺔ اﻟﻀﻮء اﻟﺼﺎدر ﻣﻦ اﻟـﻨﺠﻢ ا ﻤـﺰق ، واﻟـﺬي ﻳﺘﻀﻤﻦ اﻟﻬﻴﺪروﺟ واﻟﻜﺮﺑﻮن وﻏـ ذﻟـﻚ . ﻳﻮﻓﺮ اﻟﺘﺤﻠﻴﻞ اﻟﻄﻴﻔﻲ أدﻟﺔ ﺟﻨﺎﺋﻴﺔ ﻋﲆ ﻗﺘـﻞ اﻟﺜﻘﺐ اﻷﺳﻮد . ﻤﻞ ﺗﻌ ١ ٣ ٢