Free Astronomy Magazine May-June 2025 ARABIC VERSION

fully understand the processes at play,Yusef-Zadehsuspectstwosep- arate processes are responsible for the short bursts and longer flares. He posits that minor disturbances withintheaccretiondisklikelygen- erate the faint flickers. Specifically, turbulent fluctuations within the disk can compress plasma (a hot, electricallychargedgas)tocausea temporaryburstofradiation.Yusef- Zadeh likens these events to solar flares. “It’s similar to how the Sun’s magnetic field gathers together, compresses,andtheneruptsasolar flare,” heexplained. “Ofcourse,the processes are more dramatic be- cause the environment around a black hole is much more energetic and much more extreme. But the Sun’ssurfacealsobubbleswithac- tivity. ” Yusef-Zadeh attributes the big,brightflarestooccasionalmag- netic reconnection events — a process where two magnetic fields collide,releasingenergyintheform ofacceleratedparticles.Travelingat velocities near the speed of light, theseparticlesemitbrightburstsof radiation. “A magnetic reconnection event is like a spark of static elec- tricity, which, in a sense, also isan ‘electric reconnection,’” Yusef- Zadehsaid.BecauseWebb’sNIRCam can observe two separate wave- lengthsatthesametime(2.1and4.8 micronsinthecaseoftheseobserva- tions),Yusef-Zadehandhiscollabo- rators were able to compare how theflares’brightnesschangedwith eachwavelength.Yetagain,there- searchersweremetwithasurprise. Theydiscoveredeventsobservedat the shorter wavelength changed brightness slightly before the longer-wavelength events. “Thisisthefirsttimewehaveseen a time delay in measurements at these wavelengths,” Yusef-Zadeh said. “We observed these wave- lengths simultaneously with NIRCam andnoticedthelongerwavelength lags behind the shorter one by a very small amount — maybe a few seconds to 40 seconds.” This time delay provided more clues about the physical processes occur- ringaroundtheblackhole.Oneex- planation is that the particles lose energyoverthecourseoftheflare — losing energy quicker at shorter wavelengths than at longer wave- lengths.Suchchangesareexpected for particles spiraling around mag- netic field lines. To further explore these questions, Yusef-Zadehandhisteamhopeto useWebbtoobserveSagittarius A* for a longer period of time, such as24uninterruptedhours,tohelp reducenoiseandenablethere- searchers to see even finer details. “Whenyouarelookingatsuch weak flaring events, you have to compete with noise,” Yusef-Zadeh said. “Ifwecanobservefor24 hours, then we can reduce the noise to see features that we were unable to see before. That would be amaz- ing. We also can see if these flares repeatthemselvesoriftheyare trulyrandom.”     12 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ﻈﻬـﺮ ــﺔ اﻟﺘﺼـﻮﻳﺮ ـﺪﻳﻮ ﺘﻘﻨ ﻫــﺬا اﻟﻔ ــﻒ ﺗُﺮﺻـﺪ اﻟﺜﻘـﺐ اﻷﺳـﻮد اﻟﻤﺮﻛــﺰيﻓـﻲﻣﺠــﺮة ﻛ ﺎﻟﻔﺎﺻــﻞ اﻟـﺰﻣ در اﻟﺘ ﺎﻧـﺔ اﻟﻤﻌـﺮوف ﺎﺳـﻢ ﺳـﺎﺟ ﺘﺎر ﻮس A* ـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟ ﺑﻮاﺳـﻄﺔ ﺗﻠﺴــ ﻮبﺟـ ﻤﺲو ﻮ ﺎﻟــﺔ ﻧﺎﺳـﺎ . ﻋﻠــﻰ اﻟ ﺴــﺎر ــﺎﻣ ا اﻷﺷــﻌﺔ ﺗﺤــﺖ اﻟــ ﺗُﻈﻬــﺮﺻــﻮر ـ ــﺔ ﻤﺮاء اﻟﻘﺮ ـﺎم ) ﻧ ( ــﺪﻣﺞ ﺑ ﺎﻧــﺎت اﻟﻤُﻠﺘﻘﻄــﺔ ــﺔ ﺗـ اوح ﺑـ ـﺄﻃﻮال ﻣﻮﺟ 2.1 و 4 ﻣ ﻜـﺮون ﻧﻘﻄــﺔ ﺿـﻮء ﺗُ ﻀــﻲء وﺗُﺨﻔـﺖ ﻋﺸــﻮاﺋ . ﺎً ﻋﻠـﻰ اﻟ ﻤـ ﻳُﺮﺳـﻢ اﻟﺴﻄﻮع ﻛﺪاﻟﺔ زﻣﻨ ﺔ . رﺻﺪ ﺗﻠﺴ ﻮب و ﺐ وﻣﻀﺎتﺧﺎﻓﺘﺔ وﺗﻮﻫﺠﺎت أﻛ ﺳﻄﻮﻋ ) ﺎً ﻈﻬﺮأﺣﺪﻫﺎ ﻗـﺮ ﻧﻬﺎ ﺔ اﻟﻔ ﺪﻳﻮ .( ﻳُﺨﺘﺼﺮﻫﺬا اﻟﻔ ﺪﻳﻮ ﺣﻮاﻟﻲ 9 ﺳﺎﻋﺎت ﻣﻦ اﻟ ﺮﺻﺪ ﻓﻲ 30 ﺛﺎﻧ ﺔ . [NASA,ESA,CSA,FarhadYusef-Zadeh(Northwestern),HowardBushouse(STScI), Leah Hustak (STScI), Alyssa Pagan (STScI)] ﻹﺟ ـﺮاء اﻟﺪراﺳ ـ ﺔ اﺳ ـﺘﺨﺪم ﻳﻮﺳ ـﻒ زاده وﻓﺮﻳﻘﻪ ﻛﺎﻣ ا ﺗﻠﺴﻜﻮب ﻟ وﻳﺐ ﻸﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤ ــﺮاء اﻟﻘﺮﻳﺒ ــﺔ ) ﻧ ﻛ ــﺎم ( ﻟﺮﺻــﺪ ﺳﺎﺟﻴﺘﺎرﻳﻮس * A ﺪة 48 ﺳـﺎﻋﺔ ﺑﺰﻳـﺎدات ﺗﱰاوح ﺑ 8 و 10 ﺳﺎﻋﺎت ﻋﲆ ﻣـﺪار ﻋـﺎم ﻣﻜّﻨﻬﻢ ذﻟﻚ ﻣﻦ ﺗﺘﺒﻊ ﻛﻴﻔﻴـﺔ ﺗﻐـ اﻟﺜﻘـﺐ اﻷﺳﻮد ﺑﻤﺮ ور اﻟﻮﻗﺖ وﺑﻴﻨﻤﺎ ﺗﻮﻗﻊ اﻟﻔﺮﻳـﻖ رؤﻳﺔ ﻣﺠﺮد ﺗﻮﻫﺠﺎت ﻛـﺎن ﺎرﻳﻮس ﺳـﺎﺟﻴﺘ * A أﻛﺜﺮ ﻧﺸﺎﻃًﺎ ﻣﻤﺎ ﺗﻮﻗﻌﻮا . ﻛﺸﻔﺖ اﻷرﺻـﺎد ﻋـﻦ اﺳـﺘﻤﺮ ار ﺗﻮﻫﺠـﺎت ﻣﺘﻔﺎوﺗـﺔ اﻟﺴـﻄﻮع وا ـﺪد وأﻧـﺘﺞ ﻗـﺮص اﻟﱰاﻛﻢ ا ﺤـﻴﻂ ﺑﺎﻟﺜﻘـﺐ اﻷﺳـﻮد ﻣـﺎ ﺑـ ﺧﻤﺴﺔ وﺳﺘﺔ ﺗﻮﻫﺠﺎت ﻛﺒ ة ﻳﻮﻣﻴﺎً وﻋـﺪة ﺗﻮﻫﺠﺎت ﻓﺮﻋﻴﺔ ﺻﻐ ة ﺑﻴﻨﻬﺎ . ﻋﲆ اﻟﺮﻏﻢ ﻣﻦ أن ﻋﻠﻤﺎء اﻟﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴـﺔ ﻟﻢ ﻳﻔﻬﻤﻮا ﺑﻌﺪ اﻟﻌﻤﻠﻴـﺎت اﻟﺠﺎرﻳـﺔ ﺑﺸـﻜﻞ ﻛﺎﻣﻞ، إﻻ أن ﻳﻮﺳﻒ زاده ﻳﺸـﺘﺒﻪ ﰲ وﺟـﻮد ﻋﻤﻠﻴﺘــ ﻣﻨﻔﺼــﻠﺘ ﻣﺴــﺆوﻟﺘ ﻋــﻦ اﻻﻧ ﻔﺠﺎرات اﻟﻘﺼ ة واﻟﺘﻮﻫﺠـﺎت اﻷﻃـﻮل وﻫﻮ ﻳﻔﱰض أن اﺿﻄﺮاﺑﺎت ﻃﻔﻴﻔﺔ داﺧـﻞ ﻗﺮص اﻟﱰاﻛﻢ ﻣﻦ ا ﺮﺟﺢ أن ﺗﻮﻟﺪ اﻟﻮﻣﻀﺎت اﻟﺨﺎﻓﺘﺔ وﻋﲆ وﺟﻪ اﻟﺘﺤﺪﻳﺪ ﻳﻤﻜﻦ ﻟﻠﺘﻘﻠﺒﺎت ا ﻀﻄﺮﺑﺔ داﺧﻞ اﻟﻘﺮص أن ﺗﻀﻐﻂ اﻟ ﺒﻼزﻣﺎ ) ﻏﺎز ﺳﺎﺧ ﻦ ﻣﺸﺤﻮن ﻛﻬﺮﺑﺎﺋﻴ ( ﺎً ﻟﺘﺘﺴﺒﺐ ﰲ اﻧﻔﺠﺎر ﻣﺆﻗﺖ ﻟﻺﺷﻌﺎع وﻳﺸﺒﻪ ﻳﻮﺳﻒ زاد ه ﻫــﺬه اﻷﺣــﺪاث ﺑﺎﻟﺘﻮﻫﺠــﺎت اﻟﺸﻤﺴــﻴ ﺔ وأوﺿﺢ ﻗﺎﺋﻼً " : إﻧﻪ ﻣﺸﺎﺑﻪ ﻟﻜﻴﻔﻴﺔ ﺗﺠﻤـﻊ ا ﺠﺎل ا ﻐﻨﺎﻃﻴﴘ ﻟﻠﺸﻤﺲ واﻧﻀﻐﺎﻃﻪ ﺛـﻢ اﻧﻔﺠﺎره ﻛﺘﻮﻫﺞ ﺷﻤﴘ . ﺑـﺎﻟﻄﺒﻊ اﻟﻌﻤﻠﻴ ـﺎت أﻛﺜـﺮ دراﻣﺎﺗﻴﻜﻴـﺔ ﻷن اﻟﺒﻴﺌﺔ ا ﺤﻴﻄﺔ ﺑ ﺎﻟﺜﻘﺐ اﻷﺳﻮد أ ﻛﺜﺮ ﻧﺸـﺎﻃ ﺎً وأﻛﺜﺮ ﺗﻄﺮﻓ ﺎً ﺑﻜﺜ ﻟﻜـﻦ ﺳـﻄﺢ اﻟﺸـﻤﺲ ﻳﻐﲇ أﻳﻀ ﺎً ﺑﺎﻟﻨﺸﺎط ." ﻳﻌــﺰو ﻳﻮﺳــﻒ زاده اﻟﺘﻮﻫﺠــﺎت اﻟﻜﺒــ ة واﻟﺴــﺎﻃﻌﺔ إﱃ أﺣــﺪاث إﻋــﺎدة اﻻﺗﺼــﺎل ا ﻐﻨ ـ ﺎﻃﻴﴘ اﻟﻌﺮﺿﻴﺔ وﻫﻲ ﻋﻤﻠﻴ ﺔ ﻳﺘﺼﺎدم ﻓﻴﻬ ـﺎ ﻣﺠــﺎﻻن ﻣﻐﻨﺎﻃﻴﺴ ـﻴﺎن وﻳﻄﻠﻘ ـﺎن اﻟﻄﺎﻗﺔ ﻋـﲆ ﺷـﻜﻞ ﺟﺴـﻴﻤﺎت ﻣﺘﺴـﺎرﻋﺔ ﺗﻨﻄﻠﻖ ﺑ ﴪﻋﺎت ـ ﺗﻘـﺎرب ﴎﻋـﺔ اﻟﻀـﻮ ء ﻣﻄﻠﻘﺔ دﻓﻌﺎت ﺳﺎﻃﻌﺔ ﻣﻦ اﻹﺷﻌﺎع . ﻗﺎل ﻳﻮﺳﻒ زاده " : ﺣـﺪث إﻋـﺎدة اﻻﺗﺼـﺎل ا ﻐﻨﺎﻃــ ـ ﻴﴘ ﻳﺸــﺒﻪ ﴍارة ا ﻟﻜﻬﺮﺑ ــﺎء اﻟﺴﺎﻛﻨﺔ، واﻟﺘﻲ ﻫﻲ أﻳﻀﺎً ﺑﻤﻌﻨﻰ ﻣﺎ إﻋـﺎدة اﺗﺼـﺎل ﻛﻬﺮﺑـﺎﺋﻲ وﺑﺴـﺒﺐ ﻗـﺪرة ﻛـﺎﻣ ا NIRCam اﻟﺘﺎﺑﻌﺔ ﻟﺘﻠﺴﻜﻮب وﻳﺐ ﻋﲆ رﺻﺪ ﻧ ﻛﺎم ) ( اﻟﺘﺎﺑﻌﺔ ﻟﺘﻠﺴﻜﻮب وﻳﺐ ﻋﲆ رﺻـﺪ ﻃﻮﻟ ﻣﻮﺟﻴ ﻣﻨﻔﺼﻠ ﰲ اﻟﻮﻗﺖ ﻧﻔﺴـﻪ )2.1 و 4.8 ﻣﻴﻜﺮون ﰲ ﺣﺎﻟﺔ ﻫﺬه اﻷرﺻﺎد ( ﺗﻤﻜﻦ ﻳ ﻮﺳﻒ زاده وزﻣـﻼؤه ﻣـﻦ ﻣﻘﺎرﻧـﺔ ﻛﻴﻔﻴﺔ ﺗﻐ ﺳﻄﻮع اﻟﺘﻮﻫﺠﺎت ﻣﻊ ﻛﻞ ﻃﻮل ﻣﻮﺟﻲ وﻣﺮة أﺧﺮى ﻓﻮﺟﺊ اﻟﺒﺎﺣﺜﻮن . ﻟﻘﺪ اﻛﺘﺸـﻔﻮا أن اﻷﺣـﺪاث ا ﺮﺻـﻮدة ﻋﻨـﺪ اﻟﻄﻮل ا ﻮﺟﻲ اﻷﻗﴫ ﻐﺗ ﺳﻄﻮﻋﻬﺎ ﻗﻠﻴﻼً ﻗﺒﻞ اﻷ ﺣﺪاث ذات اﻟﻄﻮل ا ـﻮﺟﻲ اﻷﻃـﻮل . ﻗﺎل ﻳﻮﺳﻒ زاده " : ﻫﺬه ﻫﻲ ا ﺮة اﻷوﱃ اﻟﺘﻲ ﻧﺮى ﻓﻴﻬﺎ ﺗﺄﺧ ًا زﻣﻨﻴًﺎ ﰲ اﻟﻘﻴﺎﺳـﺎت ﻋﻨـﺪ ﻫﺬه اﻷﻃﻮال ا ﻮﺟﻴﺔ . ﻟﻘﺪ رﺻﺪﻧﺎ ﻫﺬه اﻷﻃـﻮال ا ﻮﺟﻴـﺔ ﰲ وﻗـﺖ واﺣﺪ ﺑﺎﺳﺘﺨﺪام ﻛﺎﻣ ا ﻧ ﻛﺎم ) رﺻـﺪﻧﺎ و ( أن اﻟﻄﻮل ا ﻮﺟﻲ اﻷﻃﻮل ﻳﺘﺄﺧﺮ ﻋﻦ اﻟﻄﻮل ا ﻮﺟﻲ اﻷﻗﴫ ﺑﻤﻘﺪار ﺻـﻐ ﺟـﺪاً رﺑﻤـﺎ ﺑﻀـﻊ ﺛـﻮانٍ إﱃ 40 ﺔ ﺛﺎﻧﻴـ وﻗـﺪ ﻗـﺪم ﻫـﺬا اﻟﺘﺄﺧ اﻟﺰﻣﻨـﻲ ا ﺰﻳـﺪ ﻣـ ﻦ اﻷدﻟـﺔ ﺣـﻮل اﻟﻌﻤﻠﻴـﺎت اﻟﻔﻴﺰﻳﺎﺋﻴـﺔ اﻟﺘـﻲ ﺗﺤـﺪث ﺣـﻮل اﻟﺜﻘﺐ اﻷﺳﻮد ﻓﺎﺋﻖ اﻟﻜﺘﻠﺔ . أﺣﺪ اﻟﺘﻔﺴ ات ﻫـﻮ أن اﻟﺠﺴـﻴﻤﺎ ت ﺗﻔﻘـﺪ ﻃﺎﻗﺘﻬﺎ ﺧﻼل ﻓﱰة اﻟﺘﻮﻫﺞ ﺑﴪﻋﺔ أﻛﱪ ﻋﻨﺪ اﻷﻃﻮال ا ﻮﺟﻴﺔ اﻷﻗ ـ ﻮال ﴫ ﻣﻘﺎرﻧﺔ ﺑـﺎﻷﻃ ا ﻮﺟﻴﺔ اﻷﻃﻮل . ﻳﺘﻮﻗــﻊ ﺣــﺪوث ﻣﺜــﻞ ﻫــﺬه اﻟﺘ ﻐــ ات ﻟﻠﺠﺴـﻴﻤﺎت اﻟﺘ ـﻲ ﺗ ـﺪور ﺣﻠﺰوﻧﻴ ـ ﺎً ﺣـﻮل ﺧﻄﻮط ا ﺠﺎل ا ﻐﻨﺎﻃ . ﻴﴘـ ﺰﻳﺪ ﻣﻦ اﺳﺘﻜﺸﺎف ﻫﺬه اﻟﺘﺴﺎؤﻻت ﻳﺄﻣـﻞ ﻳﻮﺳﻒ زاده وﻓﺮﻳ ﻘﻪ ﰲ اﺳﺘﺨﺪام ﺗﻠﺴـﻜﻮب وﻳﺐ ﻟ ﺮﺻﺪ ﺳﺎﺟﻴﺘﺎرﻳﻮس * A ﻟﻔﱰة أﻃـﻮل ﻣﺜﻞ 24 ﺳﺎﻋﺔ ﻣﺘﻮاﺻﻠﺔ ﻟﻠﻤﺴﺎﻋﺪة ﰲ ﺗﻘﻠﻴﻞ اﻟﻀﻮﺿـﺎ ء وﺗﻤﻜـ اﻟﺒـﺎﺣﺜ ﻣـﻦ رؤﻳـﺔ ﺗﻔﺎﺻﻴﻞ أدق . ﻗﺎل ﻳﻮﺳﻒ زاده " : ﻋﻨـﺪﻣﺎ ﺗﻨﻈـﺮ إﱃ ﻫـﺬه اﻷﺣــﺪاث ا ﺘﻮﻫﺠ ـﺔ اﻟﻀ ـﻌﻴﻔﺔ ﻋﻠﻴــﻚ أن ﺗﺘﻨﺎﻓﺲ ﻣﻊ اﻟﻀﻮﺿﺎء . إذا ﺗﻤﻜﻨﺎ ﻣﻦ اﻟﺮﺻﺪ ـﺪة 24 ﺳــﺎﻋﺔ ﻓﺴــﻨﺘﻤﻜﻦ ﻣ ـﻦ ﺗﻘﻠﻴ ـﻞ اﻟﻀﻮﺿـﺎء ﻟﺮؤﻳـﺔ ﻣﻴـﺰات ﻧﺮاﻫـﺎ ﺳـﺎﺑﻘﺎً و ﻳﻤﻜﻨﻨﺎ أﻳﻀ ﺎً ﻣﻌﺮﻓـﺔ ﻣـﺎ إذا ﻛﺎﻧـﺖ ﻫـﺬه اﻟﺘﻮﻫﺠﺎت ﺗﺘﻜ ﺮر أم أﻧﻬﺎ ﻋﺸﻮاﺋﻴﺔ . ﻣﺎﻳﻮ - ﻳﻮﻧﻴﻮ 2 0 2 5