Free Astronomy Magazine September-October 2023 ARABIC VERSION

i i observations of this system, the team spotted a cloud of debris at the location in PDS 70b’s orbit where Trojans are expected to exist. Trojans occupy the so-called La- grangian zones, two extended re- gions in a planet’s orbit where the combined gravitational pull of the star and the planet can trap mate- rial. Studying these two regions of PDS 70b’s orbit, astronomers de- tected a faint signal from one of them, indicating that a cloud of de- bris with a mass up to roughly two times that of our Moon might reside there. The team believes this cloud of de- bris could point to an existing Tro- jan world in this system, or a planet in the process of forming. “Who could imag- ine two worlds that share the duration of the year and the habitability condi- tions? Our work is the first evidence that this kind of world could exist,” says Balsalobre-Ru- za. “We can imag- ine that a planet can share its orbit with thousands of asteroids as in the case of Jupiter, but it is mind blowing to me that planets could share the same orbit.” “Our research is a co-orbital planets very early in their formation,” says co-author Nuria Huélamo, a senior researcher at the Centre for Astrobiology. “It opens up new questions on the formation of Trojans, how they evolve and how frequent they are in different planetary systems,” adds Itziar De Gregorio-Monsalvo, ESO Head of the Office for Science in Chile, who also contributed to this research. To fully confirm their detection, the team will need to wait until after 2026, when they will aim to use ALMA to see if both PDS 70b and its sibling cloud of debris move signifi- cantly along their orbit together around the star. “This would be a breakthrough in the exoplanetary field,” says Balsalobre-Ruza. “The future of this topic is very exciting and we look forward to the extended ALMA capabilities, planned for 2030, which will dra- matically improve the array’s abil- ity to characterise Trojans in many other stars,” concludes De Gregorio- first step to look for Monsalvo.    ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 39 ﻳﻤﻜﻦ أن ﺗﻮﺟﺪ أﻳﻀًﺎ ﺣﻮل ﻧﺠـﻢ آﺧـﺮ ﻏـ اﻟﺸﻤﺲ ﻟﻜﻦ اﻷدﻟﺔ ﻋﲆ وﺟﻮدﻫـﺎ ﺿـﺌﻴﻠﺔ . ﻳﻘﻮل ا ﺆﻟﻒ ا ﺸﺎرك ﺧﻮرﺧﻲ ﻟﻴﻠﻮ ﺑﻮﻛﺲ، وﻫﻮ ﺑﺎﺣﺚ ﰲ ﻣﺮﻛﺰ ﻋﻠﻢ اﻷﺣﻴـﺎء اﻟﻔﻠﻜـﻲ : " إن اﻟﻜﻮاﻛﺐ اﻟﻨﺠﻤﻴـﺔ - ﻛﻮاﻛـﺐ ﻃـﺮوادة ﺧﺎرج اﻟﻨﻈﺎم اﻟﺸﻤ -ﴘ ـ ﻛﺎﻧﺖ ﺣﺘـﻰ اﻵن ﻣﺜﻞ ﺣﺼﺎن وﺣﻴـﺪ اﻟﻘـﺮن : ﻣﺴـﻤﻮح ﻟﻬـﺎ ﺑﺎﻟﻮﺟﻮد ﺎً ﻧﻈﺮﻳ وﻟﻜﻦ ﻟﻢ ﻳﻜﺘﺸﻔﻬﺎ أﺣﺪ ﻋﲆ اﻹﻃﻼق ." اﻵن، اﺳـﺘﺨﺪم ﻓﺮﻳـﻖ دوﱄ ﻣـﻦ اﻟﻌﻠﻤـﺎء ﻣﺮﺻـﺪ أ ـﺎ واﻟـﺬي ﻳﻌـﺪ ا ﺮﺻـﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ ﴍﻳﻜًﺎ ﻓﻴﻪ ﻟﻠﻌﺜﻮر ﻋـﲆ أﻗﻮى دﻟﻴﻞ رﺻﺪي ﺣﺘﻰ اﻵ ن ﻋـﲆ إﻣﻜﺎﻧﻴـﺔ وﺟﻮد ﻛﻮاﻛﺐ ﻃـﺮوادة ﰲ ﻧﻈـﺎم PDS 70 . وﻣﻦ ا ﻌﺮوف أن ﻫﺬا اﻟـﻨﺠﻢ اﻟﻴـﺎﻓﻊ ﻳﻀـﻢ ﻛﻮﻛﺒ ﻋﻤ ﻼﻗ ﺷﺒﻴﻬ ﺑ ﻜﻮﻛﺐ ا ﺸـﱰي PDS 70b و PDS 70c . ﻣـﻦ ﺧـﻼل ﺗﺤﻠﻴـﻞ أرﺻﺎد ﻣﺮﺻﺪ أ ﺎ اﻷرﺷـﻴﻔﻴﺔ ﻟﻬـﺬا اﻟﻨﻈـﺎم اﻛﺘﺸﻒ اﻟﻔﺮﻳـﻖ ﺳـﺤﺎﺑﺔ ﻣـﻦ اﻟﺤﻄـﺎم ﰲ ﻣﻮﻗﻊ ﻣﺪار PDS 70b ﺣﻴـﺚ ﻣـﻦ ا ﺘﻮﻗـﻊ وﺟـﻮد أﺟﺴـﺎم . ﻃــﺮوادة ﺗﺤﺘـﻞ أﺟﺴـﺎم ﻃﺮوادة ﻣﺎ ﻳﺴﻤﻰ ﺑﻤﻨﺎﻃﻖ ﻻﻏـﺮاﻧﺞ وﻫـﻲ ﻣﻨﻄﻘﺘﺎن ﻣﻤﺘﺪﺗﺎن ﰲ ﻣﺪار اﻟﻜﻮﻛـﺐ ﺣﻴـﺚ ﻳﻤﻜﻦ ﻟﺴـﺤﺐ اﻟﺠﺎذﺑﻴـﺔ ا ﺸـﱰك ﻟﻠـﻨﺠﻢ واﻟﻜﻮﻛﺐ أن ﻳﺤﺒﺲ ا ﻮاد . ﺑﺪراﺳـﺔ ﻫـﺎﺗ ا ﻨﻄﻘﺘـ ﻣـﻦ ﻣـﺪار PDS 70b ، اﻛﺘﺸـﻒ ﻋﻠﻤﺎء اﻟﻔﻠﻚ إﺷﺎرة ﺧﺎﻓﺘـﺔ ﻣـﻦ إﺣـﺪاﻫﻤﺎ ﺗﺸ إﱃ اﺣﺘﻤﺎل وﺟﻮد ﺳﺤﺎﺑﺔ ﻣﻦ اﻟﺤﻄﺎم ﺑﻜﺘﻠﺔ ﺗﺼﻞ إﱃ ﺿﻌﻒ ﻛﺘﻠﺔ ﻗﻤﺮﻧـﺎ ﺗﻘﺮﻳﺒًـﺎ ﺑﻜﺘﻠﺔ ﺗﺼﻞ إﱃ ﺿـﻌﻒ ﻛﺘﻠ ـﺔ اﻟﻘﻤ ـﺮ ﺗﻘﺮﻳﺒ ـﺎً . ﻫﻨﺎك وﻳﻌﺘﻘﺪ اﻟﻔﺮﻳﻖ أن ﺳــﺤﺎﺑﺔ اﻟﺤﻄــﺎم ﻫﺬه ﻳﻤﻜﻦ أن ﺗﺸ إﱃ ﺟﺴﻢ ﻃﺮوادة ا ﻮﺟﻮد ﰲ ﻫ ـﺬا اﻟﻨﻈ ـﺎم أو إﱃ ﻛﻮﻛــــﺐ ﰲ ﻃــــﻮر اﻟﺘﺸــــﻜﻞ . " ﻣــــﻦ ﻳﺴﺘﻄﻴﻊ أن ﻳﺘﺨﻴﻞ ان ﻛـﻮﻛﺒ ﻳﺸـﱰﻛﺎن ﰲ ﻣــﺪة اﻟﻌـﺎم وﻇـﺮوف اﻟﺼــﻼﺣﻴﺔ ﻟﻠﺤﻴــﺎة ؟ ﺗﻘﻮل ﺑﺎﻟﺴﺎﻟﻮﺑﺮ روزا : » إن ﻋﻤﻠﻨــﺎ ﻫــﻮ أول دﻟﻴ ـﻞ ﻋ ـﲆ إﻣﻜﺎﻧﻴــﺔ وﺟﻮد ﻫﺬا اﻟﻨـﻮع ﻣـﻦ اﻟﻜﻮاﻛﺐ «. " ﻳﻤﻜﻨﻨﺎ أن ﻧﺘﺨﻴــﻞ أن اﻟﻜﻮﻛــﺐ ﻳﻤﻜﻦ أن ﻳﺸﺎرك ﻣﺪاره ﻳﻤﻜــﻦ ﻳﺸــﺎرك ﻣــﺪاره ﻣــﻊ اﻵﻻف ﻣــﻦ اﻟﻜﻮﻳﻜﺒﺎت ﻛﻤﺎ ﰲ ﺣﺎﻟـﺔ ﻛﻮﻛـ ﺐ ا ﺸـﱰي وﻟﻜﻦ ﻣﺎ ﻳﺬﻫﻠﻨﻲ ﻫﻮ أن اﻟﻜﻮ اﻛﺐ ﻳﻤﻜـﻦ أن ﺗﺸ ـﱰك ﰲ ﻧﻔ ـﺲ ا ـﺪار ." ﺗﻘ ـﻮل ﻧﻮرﻳ ـﺎ ﻫﻮﻳﻼﻣﻮ ا ﺆﻟﻔـﺔ ا ﺸـﺎرﻛﺔ وﻫـﻲ ﺑﺎﺣﺜـﺔ ﺑﺎرزة ﰲ ﻣﺮﻛﺰ ﻋﻠـﻢ اﻷﺣﻴـﺎء اﻟﻔﻠﻜـﻲ " : إن ﺑﺤﺜﻨﺎ ﻫﻮ ﺧﻄﻮة أوﱃ ﻟﻠﺒﺤﺚ ﻋﻦ اﻟﻜﻮاﻛـﺐ ذات ا ﺪارات ا ﺸﱰﻛﺔ ﰲ وﻗﺖ ﻣﺒﻜﺮ ﺟﺪًا ﻣﻦ ﺗﻜﻮﻳﻨﻬﺎ ." وﻳﻀﻴﻒ إﻳﺘﺰﻳﺎر دي ﺟﺮﻳﺠﻮرﻳـﻮ ﻣﻮﻧﺴﺎﻟﻔﻮ رﺋﻴﺲ ﻣﻜﺘﺐ اﻟﻌﻠـﻮم ﰲ ا ﺮﺻـﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ واﻟﺬي ﺳﺎﻫﻢ أﻳﻀًﺎ ﰲ ﻫﺬا اﻟﺒﺤﺚ " : إﻧـﻪ ﻳﻔـﺘﺢ أﺳـﺌﻠﺔ ﺟﺪﻳـﺪة ﺣـﻮل ﺗﻜﻮﻳﻦ اﺟﺴﺎم ﻃـﺮوادة وﻛﻴﻔﻴـﺔ ﺗﻄﻮرﻫـﺎ ووﺟﻮدﻫـﺎ ﰲ أﻧﻈﻤـﺔ ﻛﻮﻛﺒﻴـﺔ ﻣﺨﺘﻠﻔـﺔ ." ﻟﺘﺄﻛﻴ ـﺪ اﻛﺘﺸ ـﺎﻓﻬﻢ ﺳـﻴﺤﺘﺎج اﻟﻔﺮﻳ ـﻖ إﱃ اﻻﻧﺘﻈﺎر ﺣﺘﻰ ﻣﺎ ﺑﻌﺪ ﻋﺎم 2026 ﻌﺮﻓﺔ ﻣـﺎ إذا ﻛﺎن ﻛﻞ ﻣﻦ PDS 70b وﺳﺤﺎﺑﺔ اﻟﺤﻄﺎم اﻟﺸﻘﻴﻘﺔ ﻟﻪ ﻳﺘﺤﺮﻛﺎن ﺑﺸﻜﻞ ﻣﻠﺤﻮظ ﻋـﲆ ﻃﻮل ﻣﺪارﻫﻤﺎ ﻣﻌًـﺎ ﺣـﻮل اﻟـﻨﺠﻢ . ﺗﻘـﻮل ﺑ ﺎﻟﺴﺎﻟﻮﺑﺮ روزا " : ﺳﻴﺸﻜﻞ ﻫﺬا إﻧﺠﺎز اً اً ﻛﺒ ﰲ ﻣﺠﺎل اﻟﻜﻮاﻛﺐ اﻟﻨﺠﻤﻴﺔ ." - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 3 ﺎﺳــــــــــــــــــــﺘﺨﺪام ﻣ ﺼــــــــــــــــــــﻔﻮفﻣﺮﺻــــــــــــــــــــﺪ أﺗ ﺎﻣــــــــــــــــــــ ﺎ اﻟﻤﻠ ﻤــــــــــــــــــ ي / ﺗﺤــــــــــــــــــﺖ اﻟﻤﻠ ﻤــــــــــــــــــ ي اﻟﻜﺒــــــــــــــــــ أﻟﻤــــــــﺎ ) ( ،اﻛﺘﺸــــــــﻒﻋﻠﻤــــــــﺎء اﻟﻔﻠــــــــﻚ " اﻟﺸــــــــﻘﻴﻖ " ـﺪ ـﻢ ﻌ ــﺪورﺣـﻮل ﻧ اﻟﻤﺤﺘﻤـﻞ ﻟ ﻮﻛـﺐ . وﻫــﺬا اﻟﻔ ﺪﻳﻮ ﻠﺨﺺاﻻﻛﺘﺸﺎف ] ESO [. ﺗُﻈﻬــــﺮﻫــــﺬﻩ اﻟﺼــــﻮرة اﻟﻤﻠﻮﻧــــﺔ اﻟﺴــــﻤﺎء ﺣــــﻮل اﻟــــﻨ ﻢ اﻟﻘــــﺰم اﻟ ﻘـــــﺎﻟﻲ ا ﺎﻓـــﺖ ) PDS 70 ﻓــــﻲﻣﻨﺘﺼــــﻒ اﻟﺼـــﻮرة .( اﻟــــﻨ ﻢ اﻷزرق اﻟﺴــــﺎﻃﻊ اﻟﻤﻮﺟــﻮد ﻋﻠــﻰ اﻟ ﻤــ ﻫــﻮ اﻛــﺲﻗﻨﻄــﻮروس . [ESO/Digitized Sky Survey 2. Ack.: DavideDeMartin].