Free Astronomy Magazine September-October 2024

intheearlyuniversethanwerepre- viously known. A few of the new- found exploding stars are the most distant examples of their type, in- cluding those used to measure the universe’s expansion rate. “Webbisasupernovadiscoveryma- chine,” said Christa DeCoursey, a third-year graduate student at the Steward Observatory and the Uni- versity of Arizona in Tucson. “The sheer number of detections plus the greatdistancestothesesupernovae are the two most exciting outcomes from our survey.” DeCourseypresentedthesefindings in a press conference at the 244 th meetingoftheAmericanAstrono m- ical Society in Madison, Wisconsin. Tomakethesediscoveries,theteam analyzed imaging data obtained as part of the JWST Advanced Deep ExtragalacticSurvey(JADES)pro- gram. Webb is ideal for finding ex- tremely distant supernovae because their light is stretched into longer wavelengths—aphenomenon known as cosmological redshift. Prior to Webb’s launch, only a hand- fulofsupernovaehadbeenfound above a redshift of 2, which corre- sponds to when the universe was only 3.3 billion years old — just 25% of its current age. The JADES sam- ple contains many supernovae that exploded even further in the past, whentheuniversewaslessthan2 billion years old. Previously,researchersusedNASA’s HubbleSpaceTelescopetoviewsu- pernovae from when the universe was in the “young adult” stage. With JADES, scientists are seeing su- pernovaewhentheuniversewasin its“teens”or“pre-teens.”Inthefu- ture,theyhopetolookbacktothe “toddler” or “infant” phase of the universe. To discover the supernovae, the team compared multiple images taken up to one year apart and lookedforsourcesthatdisappeared orappearedinthoseimages.These objects that vary in observed bright- ness over time are called transients, and supernovae are a type of tran- sient.Inall,theJADESTransientSur- vey Sample team uncovered about 80supernovaeinapatchofskyonly about the thickness of a grain of rice held at arm’s length. “This is really our first sample of what the high-redshift universelookslikefortransientscience ,” said teammate Justin Pierel, a NASA Ein- stein Fellow at the Space Telescope Science Institute (STScI) in Balti- more, Maryland. “We are trying to identify whether distant super- novae are fundamentally different from or very much like what we see in the nearby universe.” Pierel and other STScI researchers provided expert analysis to deter- mine which transients were actually supernovae and which were not, because often they looked very sim- ilar. The team identified a number of high-redshift supernovae, including the farthest one ever spectroscopi- cally confirmed, at a redshift of 3.6. Its progenitor star exploded whenthe universe was only 1.8 billion years old. It is a so-called core-col- lapse supernova, an explosion of a massive star. Of particular interest to astrophysi- cists are Type Ia supernovae. These exploding stars are so predictably brightthattheyareusedtomeas- - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 4 29 ﻣﻌﺮوﻓﺎً ﻣﻦ ﻗﺒﻞ وﻳُﻌﺪ ﻋﺪد ﻗﻠﻴﻞ ﻣﻦ اﻟﻨﺠﻮم ا ﺘﻔﺠﺮة ا ﻜﺘﺸﻔﺔ ﺣﺪﻳﺜًﺎ أﺑﻌﺪ اﻷﻣﺜﻠﺔ ﻋـﻦ ﻧﻮﻋﻬﺎ، ﺑﻤﺎ ﰲ ذﻟﻚ ﺗﻠﻚ ا ﺴـﺘﺨﺪﻣﺔ ﻟﻘﻴـﺎس ﻣﻌﺪل ﺗﻮﺳﻊ اﻟﻜﻮن . ﻗﺎﻟﺖ ﻛﺮﻳﺴﺘﺎ دﻳﻜﻮرﳼ ﻃﺎﻟﺒـﺔ اﻟﺪراﺳـﺎت اﻟﻌﻠﻴﺎ ﰲ اﻟﺴﻨﺔ اﻟﺜﺎﻟﺜﺔ ﰲ ﻣﺮﺻـﺪ ﺳـﺘﻴﻮارد وﺟﺎﻣﻌﺔ أرﻳﺰوﻧﺎ ﰲ ﺗﻮﻛﺴﻮن " : إن ﺗﻠﺴﻜﻮب آﻟﺔ ﻮﻫ وﻳﺐ ﻻ ﻛﺘﺸﺎف ا ﺴﺘﻌﺮات اﻟﻌﻈﻤـﻰ و اﻟﻌﺪد اﻟﻬﺎﺋﻞ ﻣﻦ اﻻﻛﺘﺸﺎﻓﺎت ﺑﺎﻹﺿﺎﻓﺔ إﱃ ا ﺴﺎﻓ ﺎت اﻟﻜﺒ ة ﻟﻬﺬه ا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ ﻫﻤﺎ اﻟﻨﺘﻴﺠﺘﺎن اﻷﻛﺜﺮ إﺛﺎرة ﰲ . ﺑﺤﺜﻨﺎ وﻗـﺪ ﻋﺮﺿـ ﺖ دﻳﻜـﻮرﳼﻫـﺬه اﻟﻨﺘـﺎﺋﺞ ﰲ ﻣ ـﺆﺗﻤﺮ ﺻ ـﺤﻔﻲ ﰲ اﻻﺟﺘﻤ ـﺎع رﻗ ـﻢ 244 ﻟﻠﺠﻤﻌﻴﺔ اﻟﻔﻠﻜﻴﺔ اﻷﻣﺮﻳﻜﻴـﺔ ﰲ ﻣﺎدﻳﺴـﻮن ﺑﻮﻻﻳﺔ وﻳﺴﻜﻮﻧﺴﻦ . ﻟﺘﺤﻘﻴـﻖ ﻫـﺬه اﻻﻛﺘﺸـﺎﻓﺎت ﻗـﺎم اﻟﻔﺮﻳـﻖ ﺑﺘﺤﻠﻴﻞ ﺑﻴﺎﻧﺎت اﻟﺘﺼﻮﻳﺮ اﻟﺘﻲ ﺗﻢ اﻟﺤﺼـﻮل ﻋﻠﻴﻬﺎ ﻛﺠﺰء ﻣـﻦ ﺑﺮﻧـﺎﻣﺞ ا ﺴـﺢ اﻟﻌﻤﻴـﻖ ﺧــﺎرج ا ﺠـﺮة ا ﺘﻘـﺪم ﻟﺘﻠﺴــﻜﻮب وﻳــﺐ ﻳﻌ(. ﺟﺎدﻳﺲ ) ﺘـﱪ ﺗﻠﺴـﻜﻮب وﻳـﺐ ﻣﺜﺎﻟ ﻴـﺎً ﻟﻠﻌﺜﻮر ﻋﲆ ا ﺴـﺘﻌﺮات ا ﻟﻌﻈﻤـﻰ اﻟ ﺒﻌﻴـﺪة ﻟﻠﻐﺎﻳﺔ ﻷن ﺿﻮءﻫﺎ ﻳﻤﺘﺪ إﱃ أﻃـﻮال ﻣﻮﺟﻴـﺔ أﻃﻮل وﻫﻲ ﻇﺎﻫﺮة ﺗﻌﺮف ﺑﺎﺳـﻢ اﻻﻧﺰﻳـﺎح اﻷﺣﻤﺮ اﻟﻜﻮﻧﻲ . ﻗﺒﻞ إﻃﻼق ﺗﻠﺴﻜﻮب وﻳﺐ ﺗﻢ اﻟﻌﺜـﻮر ﻋـﲆ ﻋﺪد ﻗﻠﻴﻞ ﻓﻘﻂ ﻣـﻦ ا ﺴـﺘﻌﺮات اﻟ ﻌﻈﻤـﻰ ﻓﻮق اﻧﺰﻳﺎح أﺣﻤﺮ ﻗﺪره 2 وﻫﻮ ﻣﺎ ﻳﺘﻮاﻓـﻖ ﻣﻊ اﻟﻮﻗﺖ اﻟﺬي ﻛﺎن ﻓﻴﻪ ﻋﻤـﺮ اﻟﻜـﻮن 3.3 ﻣﻠﻴﺎر ﺳﻨﺔ ﻓﻘﻂ أي 25 % ﻓ ﻘﻂ ﻣﻦ ﻋﻤـﺮه اﻟﺤﺎﱄ . ﺗﺤﺘﻮي ﻋﻴﻨﺔ ﻣﺴـﺢ ﺟـﺎدﻳﺲ ﻋـﲆ اﻟﻌﺪﻳ ـﺪ ﻣ ـﻦ ا ﺴ ـﺘﻌﺮات اﻟ ﻌﻈﻤــﻰ اﻟﺘــﻲ اﻧﻔﺠﺮت ﺑﺸﻜﻞ أﻛﱪ ﰲ ا ﺎﴈ ﻋﻨﺪﻣﺎ ﻛـﺎن ﻋﻤﺮ اﻟﻜﻮن أﻗﻞ ﻣﻦ ﻣﻠﻴﺎري ﺳﻨﺔ . ﰲ اﻟﺴـﺎﺑﻖ اﺳـﺘﺨﺪم اﻟﺒـﺎﺣﺜﻮن ﺗﻠﺴـﻜﻮب ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟ ﻮﻛﺎﻟﺔ ﻧﺎﺳـﺎ ﻟﺮؤﻳـﺔ ا ﺴﺘﻌﺮات اﻟ ﻌﻈﻤﻰ ﻋﻨﺪﻣﺎ ﻛـﺎن اﻟﻜـﻮن ﰲ " ﻣﺮﺣﻠﺔ اﻟﺸﺒﺎب اﻟﺒﺎﻟﻎ " وﺑﺎﺳﺘﺨﺪام ﻣﺴـﺢ ﺟـﺎدﻳﺲ ﻳـﺮى اﻟﻌﻠﻤـﺎء ا ﺴـﺘﻌﺮ اﻷﻋﻈـﻢ ﻋﻨﺪﻣﺎ ﻛﺎن اﻟﻜﻮن ﰲ ﻣﺮﺣﻠﺔ ا ﺮا " أو " ﻫﻘـﺔ " ﻣﺮﺣﻠﺔ ﻣﺎ ﻗﺒـﻞ ا ﺮاﻫﻘـﺔ " وﰲ ا ﺴـﺘﻘﺒﻞ ﻳﺄﻣﻠﻮن أن ﻳﺘﻤﻜﻨﻮا ﻣـﻦ اﻟﻨﻈـﺮ إﱃ ا ﺮاﺣـﻞ ا ﺒﻜﺮة ﻣﻦ اﻟﺘﻄﻮر اﻟﻜﻮﻧﻲ . ﻻﻛﺘﺸﺎف ا ﺴﺘﻌﺮات ا ﻟﻌﻈﻤﻰ ﻗﺎرن اﻟﻔﺮﻳﻖ اً ﺻﻮر ﻣﺘﻌﺪدة ﺗﻢ اﻟﺘﻘﺎ ﻃﻬﺎ ﺑﻔﺎﺻـﻞ زﻣﻨـﻲ ﻳﺼﻞ إﱃ ﻋﺎم واﺣﺪ واﻟﺒﺤـﺚ ﻋـﻦ ا ﺼـﺎدر اﻟﺘﻲ اﺧﺘﻔﺖ أو ﻇﻬﺮت ﰲ ﺗﻠﻚ اﻟﺼﻮر . اﺧﺘﻔﺖ أو ﻇﻬﺮت ﰲ ﺗﻠـﻚ اﻟﺼـﻮر . ﺗﺴـﻤﻰ ﻫﺬه اﻷﺟﺴـﺎم اﻟﺘـﻲ ﺗﺨﺘﻠـﻒ ﰲ اﻟﺴـﻄﻮع ا ﺮﺻﻮد ﺑﻤﺮور اﻟﻮﻗـﺖ ﺑﺎﻷﺣـﺪاث اﻟﻌـﺎﺑﺮة وا ﺴﺘﻌﺮات اﻟ ﻌﻈﻤﻰ ﻫـﻲ ﻧـﻮع ﻣـﻦ ﺗﻠـﻚ اﻷﺣﺪاث . إﺟﻤﺎﻻً اﻛﺘﺸﻒ ﻓﺮﻳﻖ ﻋﻴﻨﺔ ا ﺴﺢ ﻟﻸﺣﺪاث اﻟﻌﺎﺑﺮ ة اﻟﺘﺎﺑﻊ ﺴﺢ ﺟﺎدﻳﺲ ﺣﻮاﱄ 80 ﻣﺴﺘﻌﺮ أﻋﻈﻢ ﰲ ﺑﻘﻌﺔ ﻣـﻦ اﻟﺴـﻤﺎء ﻻ ﻳﺘﺠﺎوز ﺳﻤﻜﻬﺎ ﺳﻤﻚ ﺣﺒﺔ اﻷرز . ﺖﻗﺎﻟ زﻣﻴﻠﻪ ﰲ اﻟﻔﺮﻳﻖ ﺟﻮﺳﺘ ﺑ ل زﻣﻴـﻞ ﺑﺮﻧﺎﻣﺞ أﻳﻨﺸﺘﺎﻳﻦ اﻟﺘـﺎﺑﻊ ﻟﻮﻛﺎﻟـﺔ ﻧﺎﺳـﺎ ﰲ ﻣﻌﻬــﺪ ﻋﻠــﻮم اﻟﺘﻠﺴــﻜﻮب اﻟﻔﻀــﺎﺋﻲ ﰲ ﺑﺎﻟﺘﻴﻤﻮر ﺑﻮﻻﻳﺔ ﻣ ﻳﻼﻧﺪ " : ﻫﺬه ﰲ اﻟﺤﻘﻴﻘﺔ أول ﻋﻴﻨﺔ ﻟﺪﻳﻨﺎ ـﺎ ﻳﺒـﺪو ﻋﻠﻴـﻪ اﻟﻜـﻮن ذو اﻻﻧﺰﻳـﺎح اﻷﺣﻤـﺮ اﻟﻌـﺎﱄ ﺑﺎﻟﻨﺴـﺒﺔ ﻟﻠﻌﻠـﻢ اﻟﻈﻮاﻫﺮ اﻟﻌﺎﺑﺮ ".ة " ﻧﺤﻦ ﻧﺤﺎول ﺗﺤﺪﻳ ﺪ ﻣﺎ إذا ﻛﺎﻧﺖ ا ﺴﺘﻌﺮات اﻟ ﻌﻈﻤﻰ اﻟﺒﻌﻴﺪة ﻣﺨﺘﻠﻔـﺔ ﺑﺸـﻜﻞ أﺳـﺎﳼ ﻋﻤﺎ ﻧﺮاه ﰲ اﻟﻜ ﻮن اﻟﻘﺮﻳﺐ أو ﺗﺸﺒﻬﻪ إﱃ ﺣﺪ . ﻛﺒ ﻗﺪم ﺑ ﻳـﻞ وﻏـ ه ﻣـﻦ اﻟﺒـﺎﺣﺜ ﰲ ﻣﻌﻬﺪ ﻋﻠﻮم اﻟﺘﻠﺴـﻜﻮب اﻟﻔﻀـﺎﺋﻲ ﺗﺤﻠـﻴﻼً ﻣﺘﺨﺼﺼـ ﺎ ﻟﺘﺤﺪﻳـﺪ أي اﻟﻌﻨـﺎﴏ اﻟﻌـﺎﺑﺮة ﻛﺎﻧﺖ ﰲ اﻟﻮاﻗﻊ ﻣﺴﺘﻌﺮات ﻋﻈﻤﻰ وأﻳﻬﺎ ﻟـﻢ ﺗﻜﻦ ﻛـﺬﻟﻚ ﻷﻧﻬـﺎ ﻏﺎﻟﺒـ ﺎً ﻣـﺎ ﻛﺎﻧـﺖ ﺗﺒـﺪو ﻣﺘﺸﺎﺑﻬﺔ ﺟﺪ .اً ﻟ ﻘﺪ ﺣـﺪد ا ﻟﻔﺮﻳـﻖ ﻋـﺪد اً ﻣـﻦ ا ﺴـﺘﻌﺮات اﻟﻌﻈﻤﻰ ذات اﻻﻧﺰﻳﺎح اﻷﺣﻤﺮ اﻟﻌﺎﱄ ﺑﻤـﺎ ﰲ ذﻟﻚ ا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ اﻟﺘ ﻲ ﺗـﻢ ﺗﺄﻛﻴـﺪﻫﺎ ﻃﻴﻔﻴﺎً ﻋﲆ اﻹﻃﻼق ﻋﻨﺪ اﻧﺰﻳﺎح أﺣﻤﺮ ﻗـﺪره 3.6 اﻧﻔﺠﺮ ﻧﺠﻤﻪ اﻷﺻﲇ ﻋﻨﺪﻣﺎ ﻛـﺎن ﻋﻤـﺮ اﻟﻜﻮن 1.8 ﻣﻠﻴﺎر ﺳﻨﺔ ﻓﻘﻂ إﻧﻪ ﻣﺎ ﻳﺴـﻤﻰ ﺑﺎ ﺴﺘﻌﺮ اﻷﻋﻈﻢ ذو اﻻ ﻧﻬﻴﺎر اﻷﺳﺎﳼ وﻫﻮ اﻧﻔﺠﺎر ﻟﻨﺠﻢ ﺿﺨﻢ . ﺗﻌﺘﱪ ا ﺴﺘﻌﺮات اﻟ ﻌﻈﻤﻰ ﻣﻦ اﻟﻨﻮع Ia ذات أﻫﻤﻴﺔ ﺧﺎﺻﺔ ﻟﻌﻠﻤـﺎء اﻟﻔﻴﺰﻳـﺎء اﻟﻔﻠﻜﻴـﺔ . ﺗﺘﻤﻴﺰ ﻫﺬه اﻟﻨﺠﻮم ا ﺘﻔﺠﺮة ﺑﺴﻄﻮﻋﻬﺎ اﻟﺬي ﺴﺘﺨﺪم ﺣﻘﻞ ﺟﺎد ﺲ اﻟﻌﻤﻴﻖ اﻷرﺻﺎد اﻟﺬ اﻟﺘﻘﻄ ﮫ ﺗﻠﺴ ﻮبﺟ ﻤﺲو ﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟ ﻮ ﺎﻟﺔ ﻧﺎﺳـﺎ ﺠـﺰء ﻣـﻦ ﺑﺮـﺎ ﺞ ﻣ اﻟﻤﺴـﺢ اﻟﻌﻤﻴـﻖﺧـﺎرج اﻟﻤﺠـﺮة اﻟﻤﺘﻘــﺪم ـﺐ ﻟﺘﻠﺴـ ﻮب و . ﺣــﺪد ﻓﺮ ـﻖ ﻣـﻦ ﻋﻠﻤــﺎء اﻟﻔﻠــﻚ اﻟــﺬﻳﻦ ﺪرﺳـﻮن ﺑ ﺎﻧــﺎت ﻣﺴــﺢ ﺟـﺎد ﺲ ﺣــﻮاﻟﻲ 80 ) ﺎً ﺟﺴــﻤ ﺎً ﻣﺤﺎﻃــ ـﺎﻟﻠﻮن اﻷﺧﻀــﺮ ــﺪاﺋﺮة ( ﺘﻐــ ﺳــﻄﻮﻋﻬ ﺎ ﻤـــﺮور اﻟﻮﻗـــﺖ . ﻣﻌﻈـــﻢ ﻫــﺬﻩ اﻷﺟﺴـــﺎم اﻟﻤﻌﺮوﻓـــﺔ ﺎﻟﻌـــﺎﺑﺮ ة ﻫــﻲ ﻧﺘﻴﺠـــﺔ ا ﻧﻔﺠـــﺎراﻟﻨﺠـــﻮم أو اﻟﻤﺴﺘﻌﺮات ا ﻟﻌﻈﻤﻰ ﻗ. ﺒﻞ ﻫﺬا اﻟﻤﺴـﺢ ﺗـﻢ اﻟﻌﺜـﻮرﻋﻠـﻰ ﻋـﺪد ﻗﻠﻴـﻞ ﻓﻘـﻂﻣـﻦ اﻟﻤﺴـﺘﻌﺮات اﻟ ﻌﻈﻤـﻰ ﻓـﻮق اﻟﺘﺤــﻮل اﻷ ﻤـﺮ ﻤﻘــﺪار 2 ـﮫ ــﺎن ﻓ وﻫـﻮ ﻣـﺎ ﺘﻮاﻓـﻖ ﻣـﻊ اﻟﻮﻗــﺖ اﻟـﺬ ﻋﻤــﺮ ـﻮن اﻟ 3.3 ــﺎرﺳــﻨﺔ ﻣﻠ ﻓﻘــﻂ أي 25 % ﻓﻘــﻂﻣــﻦ ﻋﻤــﺮﻩ اﻟــ ـ . ﺤﺎﻟﻲ ﺗﺤﺘــﻮيﻋ ﻨــﺔ ﻣﺴــﺢ ﺟـﺎد ﺲ ــﺪ ﻣــﻦ اﻟﻤﺴــﺘﻌﺮات ﻋﻠــﻰ اﻟﻌﺪ اﻻ ﻟﻌﻈﻤﻰ اﻧﻔﺠﺮ أﻛ ﻓﻲ اﻟﻤﺎﺿﻲ اﻟ ﻋﻨﺪﻣﺎ ﺎن ﻋﻤﺮاﻟ ﻮن أﻗﻞ ﻣـﻦ 2 ـ ﺎرﺳـﻨﺔ ﻣﻠ وﻫـﻲ ﺗ ﺘﻀـﻤﻦ أ ﻌــﺪ اﻧﻔﺠــﺎر ــﺎً ــﺪﻩ ﻃ ﻔ ﺗــﻢ ﺗﺄﻛ وﻫـﻮ اﻟﺘﺤــﻮل اﻟﻤﺘﻐــ ﻤﻘــﺪار 0306 واﻧﻔﺠــﺮﻧ ﻤــﮫ اﻟﺴـﺎﺑﻖ ــﺎن ﻋﻨــﺪﻣﺎ ﻋﻤﺮاﻟ ﻮن 1.8 ﻣﻠ ﺎرﺳﻨﺔ ﻓﻘﻂ .