Free Astronomy Magazine November-December 2024 ARABIC VERSION

closest individual star to us. Owing toitsproximity,itisaprimarytarget inthesearchforEarth-likeexoplan- ets. Despite a promising detection back in 2018, no planet orbiting Barnard’s star had been confirmed until now. Thediscoveryofthisnewexoplanet — announced in a paper published in the journal Astronomy & Astro- physics —istheresultofobserva- tions made over the last five years with ESO’s VLT, located at Paranal Observatory in Chile. “Even if it took a long time, wewere always confident that wecould find something,” says Jonay González Hernández, a researcherat the Instituto de Astrofísica de Ca- narias in Spain, and lead author of the paper. The team were lookingforsignalsfrompossibleexoplan ets within the habitable or temperate zone of Barnard’s star — the range whereliquidwatercanexistonthe planet’ssurface.Reddwarfslike Barnard’sstarareoftentargetedby astronomerssincelow-massrocky planets are easier to detect there than around larger Sun-like stars. Barnardb],asthenewlydiscovered exoplanetiscalled,istwentytimes closertoBarnard’sstarthanMer- ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 5 ﺎﺳﺘﺨﺪام اﻟﺘﻠﺴ ﻮب اﻟﻜﺒ ﺟﺪاً اﻟﺘﺎﺑﻊ ﻟﻠﻤﺮﺻﺪ اﻷوروﺑﻲ اﻟ ـ ﺠﻨﻮﺑﻲ اﻛﺘﺸﻒ ﻋﻠﻤــﺎء اﻟﻔﻠــﻚ ــﻢ إﻟـــ ــﻢ ﺑﺮـــﺎرد أﻗــﺮ ﻧ ـــﺪورﺣــﻮل ﻧ ــﺎ ﻮﻛ ﻟﻘــﺪ . ﻰ اﻟﺸــﻤﺲ ﺗـــﻢ ﺗ ﻠـﻎ ﻛﺘﻠﺘــﮫ ﻧ اﻟﻌﺜـﻮرﻋﻠــﻰ اﻟ ﻮﻛـﺐ اﻟــﺬ ﺼــﻒﻛﺘﻠـﺔ ﻮﻛــﺐ اﻟﺰﻫـﺮة ﻋﻠــﻰ اﻷﻗــﻞ ﻋﻦ ﻃﺮﻖ اﻟﺴـﺤﺐ أﻟﺘﺠـﺎذﺑﻲ اﻟـﺬ ـﮫ ﻘـﻮم ﻋﻠـﻰ ﻧ ﻤـﮫ اﻟﻤﻀـ ﻒ . ﻠﺨـﺺﻫـﺬا اﻟﻔ ﺪﻳﻮ اﻻﻛﺘﺸﺎف . ﻧﻮ - ﻓﻤﺒﺮ ﺩﻳﺴﻤﺒﺮ 2 0 2 4 اﻟﺠﻨﻮﺑﻲ اﻟﻮاﻗﻊ ﰲ ﻣﺮﺻﺪ ﺑﺎراﻧﺎل ﰲ ﺗﺸﻴﲇ . ﻳﻘﻮل ﺟﻮﻧﺎي ﺟﻮ ﻧﺰاﻟﻴﺲ ﻫ ﻧﺎﻧﺪﻳﺰ اﻟﺒﺎﺣﺚ ﰲ ﻣﻌﻬﺪ اﻟﻔﻴﺰﻳﺎء اﻟ ﻔﻠﻜﻴﺔ ﰲ ﺟﺰر اﻟﻜﻨﺎري ﰲ إﺳﺒﺎﻧﻴﺎ وا ﺆﻟﻒ اﻟﺮﺋﻴﴘ ﻟﻠﻮرﻗـﺔ اﻟﺒﺤﺜﻴـﺔ : ﺣ" ﺘﻰ ﻟﻮ اﺳﺘﻐﺮق اﻷﻣﺮ وﻗﺘًـﺎ ﻃـﻮﻳﻼً ﻛﻨـﺎ ﺎً داﺋﻤ ﻋﲆ ﺛﻘﺔ ﻣﻦ ﻗﺪرﺗﻨﺎ ﻋﲆ اﻟﻌﺜـﻮر ﻋـﲆ ". ﳾء ﻣﺎ ﻛﺎن اﻟﻔﺮﻳ ﻖ ﻳﺒﺤﺚ ﻋﻦ إﺷـﺎرات ﻣﻦ ﻛﻮاﻛﺐ ﻧﺠﻤﻴﺔ ﻣﺤﺘﻤﻠﺔ داﺧﻞ ا ﻨﻄﻘـﺔ ا ﻟﺼﺎﻟﺤﺔ ﻟﻠﺤﻴﺎة أو ا ﻌﺘﺪﻟـﺔ ﻟـﻨﺠﻢ ﺑﺮﻧـﺎرد وﻫﻲ اﻟﻨﻄﺎق اﻟﺬي ﻳﻤﻜﻦ أن ﻳﻮﺟﺪ ﻓﻴﻪ ا ـﺎء اﻟﺴـﺎﺋﻞ ﻋـﲆ ﺳـﻄﺢ اﻟﻜﻮﻛـﺐ . ﻏﺎﻟﺒًـﺎ ﻣـﺎ ﻓﻬﻮ ﻫﺪف أﺳﺎﳼ ﰲ اﻟﺒﺤﺚ ﻋـﻦ ﻛﻮاﻛـﺐ ﻧﺠﻤﻴـﺔ ﺗﺸـﺒﻪ اﻷرض وﻋـﲆ اﻟـﺮﻏﻢ ﻣــﻦ اﻻﻛﺘﺸﺎف اﻟﻮاﻋﺪ ﰲ ﻋﺎم 2018 ﻟﻢ ﻳﺘﻢ ﺗﺄﻛﻴﺪ أي ﻛﻮﻛﺐ ﻳﺪور ﺣﻮل ﻧﺠﻢ ﺑﺮﻧﺎرد ﺣﺘﻰ اﻵن . ا إن ﻛﺘﺸﺎف ﻫﺬا اﻟﻜﻮﻛﺐ اﻟﻨﺠﻤـﻲ ا ﻟﺠﺪﻳـﺪ اﻟﺬي أُﻋﻠﻦ ﻋﻨﻪ ﰲ ورﻗﺔ ﺑﺤﺜﻴـﺔ ﻧُـ ـ ﴩت ﰲ ﻣﺠﻠﺔ اﻟﻔﻠﻚ واﻟﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ ﻫـﻮ ﻧﺘﻴﺠـﺔ ﻟﻸرﺻﺎد اﻟﺘﻲ أﺟﺮﻳﺖ ﻋـﲆ ﻣـﺪى اﻟﺴـﻨﻮات اﻟﺨﻤـﺲ ا ﺎﺿــﻴﺔ ﺑﺎﺳـﺘﺨﺪام اﻟﺘﻠﺴـﻜﻮب اﻟﻜﺒ ـ ﺟــﺪأً اﻟﺘ ـﺎﺑﻊ ﻟﻠﻤﺮﺻ ـﺪ اﻷوروﺑ ـﻲ اﻟﺠﻨﻮﺑﻲ اﻟﻮاﻗﻊ ﰲ ﻣﺮﺻﺪ ﺑﺎراﻧﺎل ﰲ ﺗﺸﻴﲇ .. اﻟﺴـﺎﺋﻞ ﻋـﲆ ﺳـﻄﺢ اﻟﻜﻮﻛـﺐ . ﺎً ﻏﺎﻟﺒـ ﻣـﺎ ﻳﺴﺘﻬﺪف ﻋﻠﻤﺎء اﻟﻔﻠﻚ اﻷﻗﺰام اﻟﺤﻤﺮاء ﻣﺜﻞ ﻧﺠﻢ ﺑﺮﻧـﺎرد ﻷن اﻟﻜﻮاﻛـﺐ اﻟﺼـﺨﺮﻳﺔ ذات اﻟﻜﺘﻠﺔ ا ﻨﺨﻔﻀﺔ أﺳﻬﻞ ﰲ اﻻﻛﺘﺸﺎف ﻫﻨﺎك ﻣﻘﺎرﻧﺔ ﺑﺘﻠﻚ اﻟﻜﻮاﻛﺐ ﺣﻮل اﻟﻨﺠﻮم اﻷﻛـﱪ ﺣﺠﻤﺎ ﻣﺜﻞ اﻟﺸﻤﺲ . ﺑﺮﻧـﺎرد (ب) ﻛﻤ ـﺎ ﻳُﻄﻠ ـﻖ ﻋـﲆ اﻟﻜﻮﻛ ـﺐ اﻟﻨﺠﻤﻲ ا ﻜﺘﺸﻒ ﺣﺪﻳﺜﺎً أﻋﻮ ﻗﺮب إﱃ ﻧﺠـﻢ ﺑﺮﻧﺎرد ﺑﻌﴩﻳﻦ ﻣﺮة ﻣﻘﺎرﻧﺔ ﺑﺎ ﺴﺎﻓﺔ اﻟﺘﻲ ﺗﻔﺼﻞ ﻛﻮﻛﺐ ﻋﻄﺎرد ﻋﻦ اﻟﺸﻤﺲ .