Free Astronomy Magazine May-June 2025 ARABIC VERSION

U Planetary system found around Barnard’s Star byNOIRLab JosieFenske5LouiseLerner singinparttheGeminiNorth telescope,onehalfoftheIn- ternationalGeminiObserva- tory, partly funded by the U.S. Na- tionalScienceFoundationandoper- ated by NSF NOIRLab, astronomers have discovered four sub-Earth ex- oplanets orbiting Barnard’s Star, the nearestsinglestarsystemtoEarth. Oneoftheplanetsistheleastmas- sive exoplanet ever discovered us- ing the radial velocity technique, indicatinganewbenchmarkfordis- covering smaller planets around nearby stars. For a century, astronomers have beenstudyingBarnard’sStarinthe hope of finding planets around it. FirstdiscoveredbyE.E.Barnardat YerkesObservatoryin1916,itisthe nearestsinglestarsystemtoEarth. Barnard’s Star is classified as a red dwarf — low-mass stars that often host closely-packed planetary sys- tems, often with multiple rocky planets. Red dwarfs are extremely numerousintheUniverse,soscien- tists are interested in understand- ingtheenvironmentsoftheplanets they host. ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 4 ﻋﻠﻤﺎء اﻟﻔ ﻠﻚ ﻜﺘﺸﻔﻮن ﻧﻈﺎﻣﺎً ﺎً ﻮﻛﺒ ﺣﻮل ﻧ ﻢ ﺑﺮ ﺎرد : ﻘﻠﻢ ﺟﻮزيﻓ ﻨﺴﻜﻲ و ﻟﻮﻳﺰ ﻟ ﺮ ﻣﺨﺘ ﻧﻮﻳﺮﻻب ﺎﻟﺘﻌـﺎون ﻣﻊ ﺗﻠﺴﻜﻮب ﺟﻴﻤﻴﻨـﻲ ﻧـﻮرث اﻟﺬي ﻳﻤﺜﻞ ﻧﺼﻒ ﻣﺮﺻـﺪ ﺟﻴﻤﻴﻨـﻲ اﻟـﺪوﱄ وا ﻤﻮل ﻣﻦ ﻗ ﺒﻞ ا ﺆﺳﺴﺔ اﻟﻮﻃﻨﻴﺔ ﻟﻠﻌﻠـﻮم اﻷﻣﺮﻳﻜﻴﺔ واﻟـﺬي ﻳـ ﺪﻳﺮه ﻣﺨﺘـﱪ ﻧـﻮﻳﺮﻻب اﻛﺘﺸﻒ ﻓﺮﻳـﻖ ﻣـﻦ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ أرﺑﻌـﺔ ﻛﻮاﻛﺐ ﻧﺠﻤﻴﻪ ﺗﺪور ﺣﻮل ﻧﺠﻢ ﺑﺮﻧﺎرد أﻗﺮب ﻧﻈﺎم ﻧﺠﻤﻲ أﺣﺎدي إﱃ اﻷرض . ﻳُ ﻌـﺪ أﺣـﺪ ﻫـﺬه اﻟﻜﻮاﻛـﺐ ا ﻜﺘﺸـﻔﺔ أﻗـﻞ اﻟﻜﻮاﻛ ﺐ اﻟﻨﺠﻤﻴﺔ ﻛﺘﻠﺔً ﻋﲆ اﻹﻃﻼق اﻛﺘُﺸﻒ ﺑﺎﺳﺘﺨﺪام ﺗﻘﻨﻴﺔ اﻟﴪﻋﺔ اﻟﺸـﻌﺎﻋﻴﺔ ﻣﻤـﺎ ﻳُﺸ إﱃ ﻣﻌﻴﺎر ﺟﺪﻳﺪ ﻻﻛﺘﺸـﺎف اﻟﻜﻮاﻛـﺐ اﻟﻨﺠﻤﻴﺔ اﻷﺻﻐﺮ ﺣﻮل اﻟﻨﺠـﻮم اﻟﻘﺮﻳﺒـﺔ ﰲ ﺳﻌﻴﻨﺎ اﻟﺒﺤﺚ ﻋﻦ ﻛﻮاﻛﺐ ﺻﺎﻟﺤﺔ ﻟﻠﺤﻴﺎة رﺳــــﻢ ﺗﺨ ﻠـــــﻲ ﺗـــــﺪور ـــــﺔ اﻟــــ ﻟﻠ ﻮاﻛــــﺐ اﻟﻨ ﻤ ﺣﻮل ﻧ ﻢ ﺎرﺎرد ]. InternationalGemini Observatory/NOIRLab/NSF/AURA/ P. Marenfeld [ ﻋﲆ ﻣﺪى ﻗﺮن ﻣﻦ اﻟﺰﻣﺎن دأب ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻋﲆ دراﺳﺔ ﻧﺠﻢ ﺑﺮﻧﺎرد ﺑﻬﺪف اﻟﻌﺜﻮر ﻋـﲆ ﻛﻮاﻛﺐ ﺗﺪور ﺣﻮﻟﻪ . اﻛﺘُﺸﻒ ﻷول ﻣﺮة ﺑﻮاﺳﻄﺔ إي . إي. ﺑﺮﻧـﺎرد ﰲ ﻣﺮﺻﺪ ﻳﺮﻛﻴﺰ ﻋﺎم 1916 وﻫﻮ أﻗﺮب ﻧﻈﺎم ﻧﺠﻤﻲ أﺣﺎدي إﱃ اﻷرض . ﻳُﺼﻨﻒ ﻧﺠﻢ ﺑﺮﻧﺎرد ﻛﻨﺠﻢ ﻗﺰم أﺣﻤﺮ وﻫـﻲ ﻧﺠﻮم ﻣﻨﺨﻔﻀﺔ اﻟﻜﺘﻠﺔ ﻏﺎﻟﺒًﺎ ﻣﺎ ﺗﺴﺘﻀـﻴﻒ أﻧﻈﻤﺔ ﻛﻮﻛﺒﻴﺔ ﻣﱰاﺻﺔ ﺗﺤﺘﻮي ﻏﺎﻟﺒًﺎ ﻋـﲆ ﻛﻮاﻛﺐ ﺻﺨﺮﻳﺔ ﻣﺘﻌﺪدة . ﺗُﻌﺪ اﻷﻗﺰا م اﻟﺤﻤﺮاء وﻓ ة ﻟﻠﻐﺎﻳﺔ ﰲ اﻟﻜـﻮن ﻟﺬا ﻳﻬﺘﻢ اﻟﻌﻠﻤﺎء ﺑﺸﻜﻞ ﻛﺒ ﻟ ﻔﻬـﻢ ﺑﻴﺌـﺎت اﻟﻜﻮاﻛﺐ اﻟﺘﻲ ﺗﺴﺘﻀﻴﻔﻬﺎ . ﻣﺎﻳﻮ - ﻳﻮﻧﻴﻮ 2 0 2 5