Free Astronomy Magazine November-December 2024 ARABIC VERSION

G tive distancesbetween thenear- raphicrepresentationoftherela- eststarsandtheSun.Barnard’sstaris thesecondcloseststarsystemtothe Sun,andthenearestsinglestartous. [IEEC/Science-Wave–GuillemRamisa] than the habitable zone,” explains González Hernández. “Even if the star is about 2500 degrees cooler than our Sun, it is too hot there to maintain liquid water on the sur- face.” For their observations, the teamusedESPRESSO,ahighlyprecisein- strument designed to measure the wobbleofastarcausedbythegrav- itational pull of one or more orbit- ing planets. The results obtained from these observations were con- firmed by data from other instru- mentsalsospecialisedinexoplanet hunting:HARPSatESO’sLaSillaOb- servatory,HARPS-NandCARMENES. Thenewdatadonot,however,sup- porttheexistenceoftheexoplanet reported in 2018. Inadditiontotheconfirmedplanet, the international team also found hints of three more exoplanet can- didates orbiting the same star. Thesecandidates,however,willre- quire additional observations with ESPRESSO to be confirmed. “We now need to continue observ- ing this star to confirm the other candidate signals,” says Alejandro Suárez Mascareño, a researcher also attheInstitutodeAstrofísicadeCa- narias and co-author of the study. “But the discovery of this planet, along with other previous discover- ies such as Proxima b and d, shows that our cosmic backyard is full of low-mass planets.” ESO’s Extremely Large Telescope (ELT), currently under construction, is set to transform the field of exo- planetresearch.TheELT’sANDESin- strument will allow researchers to detect more of these small, rocky planets in the temperate zonearound nearby stars, beyond the reach of current telescopes, and en- able them to study the composition o ftheiratmospheres.     ﺗﻤﺜﻴـــــﻞ أﻗـــــﺮ اﻟﻨﺠـــــﻮم ـــــﺎﻧﻲ ﻟﻠﻤﺴـــــﺎﻓﺔ ﺑـــــ ﺑ واﻟﺸـــﻤﺲ . ـــﻢ ﺑﺮـــﺎرد ﻫـــﻮ ﺛـــﺎﻧﻲ أﻗـــﺮ ﻧﻈــــﺎم ﻧ ﻧ ﻤﻲ إﻟﻰ اﻟﺸﻤﺲ ـﻢ ﻣﻨﻔـﺮد ﻣﻨﻬـﺎ وأﻗﺮ ﻧ . ] IEEC/Science-Wave–GuillemRamisa [ ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 7 7 ﻳﻮﺿﺢ ﺟﻮﻧﺰاﻟﻴﺲ ﻫ ﻧﺎﻧﺪﻳﺰ : " ﺣﺘﻰ ﻟﻮ ﻛﺎن اﻟﻨﺠﻢ أﺑﺮد ﻣﻦ ﺷﻤﺴﻨﺎ ﺑﺤﻮاﱄ 2500 درﺟـﺔ ﻓﺈﻧﻪ ﺳﺎﺧﻦ ﺟﺪ اً ﻟﻠﺤﻔﺎظ ﻋﲆ ا ﺎء اﻟﺴـﺎﺋﻞ ﻋﲆ اﻟﺴﻄﺢ ." اﺳﺘﺨﺪم اﻟﻔﺮﻳﻖ ﻣﻄﻴﺎف إﺳﱪﺳﻮ وﻫﻲ أدا ة ﻋﺎﻟﻴﺔ اﻟﺪﻗﺔ ﻣﺼﻤﻤﺔ ﻟﻘﻴﺎس ﺗﺬﺑﺬب اﻟـﻨﺠﻢ اﻟﻨـﺎﺗﺞ ﻋﻦ اﻟﺠﺎذﺑﻴﺔ ﻟﻜﻮﻛﺐ واﺣﺪ أو أﻛﺜـﺮ ــ ﻳـﺪور ﺣﻮﻟـﻪ . ﺗـﻢ ﺗﺄﻛﻴـﺪ اﻟﻨﺘـﺎﺋﺞ اﻟﺘـﻲ ﺗـﻢ اﻟﺤﺼﻮل ﻋﻠﻴﻬﺎ ﻣﻦ ﻫﺬه اﻷرﺻﺎد ﻣـ ﻦ ﺧـﻼل اﻟﺒﻴﺎﻧﺎت ﻣﻦ أﺟﻬﺰة أﺧﺮى ﻣﺘﺨ ﰲ ﺎً ﺼﺼﺔ أﻳﻀ رﺻﺪ اﻟﻜﻮاﻛﺐ اﻟﻨﺠﻤﻴﺔ : ﻣﺜﻞ ﻣﻄﻴﺎف ﻫﺎرﺑﺲ ﰲ ﻣﺮﺻﺪ ﻻﺳـﻴﻼ اﻟﺘـﺎﺑﻊ ﻟﻠﻤﺮﺻـﺪ اﻷوروﺑـﻲ اﻟﺠﻨﻮﺑﻲ وﻣﻄﻴﺎف ) ( ان- ﻫـﺎرﺑﺲ وﻣﻄﻴـﺎف ﻛـﺎرﻣﻴﻨﻴﺲ وﻣ ـﻊ ذﻟ ـﻚ ﻻ ﺗــﺪﻋﻢ اﻟﺒﻴﺎﻧ ـﺎت اﻟﺠﺪﻳﺪة وﺟﻮد اﻟﻜﻮﻛﺐ اﻟﻨﺠﻤﻲ ا ﺸﺎر اﻟﻴﻪ ﰲ أرﺻﺎد ﻋﺎم 2018 . ﺑﺎﻹﺿﺎﻓﺔ إﱃ اﻟﻜﻮﻛـﺐ ا ﺆﻛـﺪ وﺟـﺪ اﻟﻔﺮﻳـﻖ اﻟﺪوﱄ ﺎً ﻳﻀأ إﺷـﺎرات ﻟﻮﺟـﻮد ﺛﻼﺛـﺔ ﻛﻮاﻛـﺐ ﻧﺠﻤﻴﺔ ﻣﺤﺘﻤﻠﺔ أﺧﺮى ﺗ ﺪور ﺣﻮل ﻧﻔﺲ اﻟﻨﺠﻢ وﻣﻊ ذﻟﻚ ﺳﻴﺤﺘﺎج اﻟﻌﻠﻤﺎء ﻟ ﺘﺄﻛﻴﺪ وﺟﻮد ﻫـﺬه اﻟﻜﻮاﻛـﺐ ا ﺤﺘﻤﻠـﺔ إﺟـﺮاء أرﺻـﺎد إﺿـﺎﻓﻴﺔ ﺑﺎﺳﺘﺨﺪام ﻣﻄﻴﺎف إﺳﱪﺳﻮ . ﻳ ﻘﻮل أﻟﻴﺨﺎﻧﺪرو ﺳﻮارﻳﺰ ﻣﺎﺳـﻜﺎرﻳﻨﻴﻮ وﻫـﻮ ﺑﺎﺣﺚ أﻳﻀ ﰲ ﻣ ﺎُ ﻌﻬﺪ اﻟﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ ﰲ ﺟﺰر اﻟﻜﻨﺎري وا ﺆﻟﻒ ا ﺸﺎرك ﻟﻠﺪراﺳﺔ " : ﻣﻦ اﺟﻞ ﻧﺘﺎﺋﺞ أﻓﻀﻞ وﻣﺆﻛـﺪة ﺣـﻮل ﻫـﺬه اﻟﻜﻮاﻛـﺐ ﻧﺤﺘــ ﺎج اﻵن إﱃ اﻟﻘﻴــﺎم ﺑ ﻤﻮاﺻــﻠﺔ ﻣﺮاﻗﺒــﺔ ـــــــ ﻫﺬا اﻟﻨﺠﻢ ﻟﺘﺄﻛﻴﺪ إﺷﺎرات اﻟﻜﻮاﻛﺐ ا ﺤﺘ ﻤﻠﺔ اﻷﺧﺮى ان ﻛﺎﻧﺖ ﻣﻮﺟﻮدة ﻟﻜﻦ اﻛﺘﺸﺎف ﻫﺬا اﻟﻜﻮﻛﺐ إﱃ ﺟﺎﻧﺐ اﻛﺘﺸﺎﻓﺎت ﺳﺎﺑﻘﺔ أﺧـﺮى ﻣﺜﻞ ﺑﺮوﻛﺴﻴﻤﺎ و ﺑﻲ ﺑﺮوﻛﺴﻴﻤﺎ دي ، ﻳُﻈﻬـﺮ أن ﺟﻮارﻧﺎ اﻟﻜﻮﻧﻲ ﻣﲇء ﺑﺎﻟﻜﻮاﻛﺐ ذات اﻟﻜﺘﻠﺔ ا ﻨﺨﻔﻀﺔ ." اﻟ إن ﺘﻠﺴﻜﻮب اﻟﻌﻤﻼق ﻟﻠﻐﺎﻳﺔ اﻟﺘﺎﺑﻊ ﻟﻠﻤﺮﺻﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ ﻗﻴﺪ اﻹﻧﺸﺎء ﺣﺎﻟﻴ ﺎً ﺳـﻴﻐ أﺑﺤﺎ ث اﻟﻜﻮاﻛـﺐ اﻟ ﻨﺠﻤﻴـﺔ ﺣﻴـﺚ ﺳﻴﺴـﻤﺢ ﺑﺎﻛﺘﺸﺎف ا ﺰﻳـﺪ ﻣـﻦ اﻟﻜﻮاﻛـﺐ اﻟﺼـﺨﺮﻳﺔ اﻟﺼﻐ ة ﰲ ا ﻨ ﻄﻘﺔ ا ﻌﺘﺪﻟـﺔ ﺣـﻮل اﻟﻨﺠـﻮم اﻟﻘﺮﻳﺒ ـﺔ واﻟﺘ ـﻲ ﻻ ﺗﺮﺻـﺪﻫﺎ اﻟﺘﻠﺴـﻜﻮﺑﺎت اﻟﺤﺎﻟﻴﺔ وﻳﻤﻜﻦ اﻟﻌﻠﻤﺎء ﻣﻦ دراﺳـﺔ ﺗﻜـﻮﻳﻦ ﻏﻼﻓﻬﺎ اﻟﺠﻮي . ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 4