Free Astronomy Magazine September-October 2023 ARABIC VERSION

W Different rock constituents detected in a hot exoatmosphere by NOIRLab − Charles Blue ASP-76b is a strange world. Located 634 light- years from Earth in the di- rection of the constellation of Pisces, the Jupiter-like exoplanet or- bits its host star at an exceptionally close distance — approximately 12 times closer than Mercury is to the Sun — which heats its atmosphere to a searing 2000°C. Such extreme temperatures have “puffed up” the planet, increasing its volume to nearly six times that of Jupiter. At such extreme temperatures, min- eral- and rock-forming elements, which would otherwise remain hid- den in the atmosphere of a colder gas-giant planet, can reveal them- selves. Using the Gemini North tele- scope, one half of the International Gemini Observatory operated by NSF’s NOIRLab, an international team of astronomers has detected 11 of these rock-forming elements in the atmosphere of WASP-76b. The presence and relative amounts of these elements can provide key insights into exactly how giant gas planets form — something that re- mains uncertain even in our own Solar System. The results are pub- lished in the journal Nature . Since its discovery in 2013 during the Wide Angle Search for Planets (WASP) program, many astronomers have studied the enigmatic WASP- 76b. These studies have led to the identification of various elements present in the hot exoplanet’s at- mosphere. Notably, in a study pub- lished in March 2020, a team concluded that there could be iron rain on the planet. Aware of these existing studies, Ste- fan Pelletier, a PhD student with the Trottier Institute for Research on Ex- oplanets at the Université de Mon- tréal and lead author on the paper, was inspired to explore the myster- ies of this strange exoplanet and the chemistry of its searing atmosphere. In 2020 and 2021, using Gemini North’s MAROON-X (a new instru- ment specially designed to detect and study exoplanets), Pelletier and his team observed the planet as it passed in front of its host star on three separate occasions. These new observations uncovered a number of rock-forming elements in the at- mosphere of WASP-76b, including sodium, potassium, lithium, nickel, manganese, chromium, magnesium, vanadium, barium, calcium, and, as previously detected, iron. Due to the extreme temperatures of WASP-76b’s atmosphere, the ele- ments detected by the researchers, which would normally form rocks here on Earth, are instead vaporized and thus present in the atmosphere in their gaseous forms. While these SEPTEMBER-OCTOBER 2023 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 22 إ ﻛﺘﺸﺎفﻣ ﻮﻧﺎتﺻﺨﺮ ﺔ ﻣﺨﺘﻠﻔﺔ ﻓﻲ ﻏﻼف ﺟﻮي ﺳﺎﺧﻦ ﻟ ﻮﻛﺐ ﻧ ﻤﻲ : ﻘﻠﻢ ﺗﺸﺎرﻟﺰ ﻠﻮ – ﻣﺨﺘ ﻧﻮﻳﺮﻻب إﻧـ اﻟﻜﻮﻛﺐ أﻟﻨﺠﻤـﻲ WASP-76b اﻟﺸـﺒﻴﻪ ﺑﻜﻮﻛﺐ ا ﺸـﱰي ﻫـﻮ ﻋـﺎﻟﻢ ﻏﺮﻳـﺐ ﻳﺒﻌـﺪ ﻣﺴـﺎﻓﺔ 634 ﺳـﻨﺔ ﺿـﻮﺋﻴﺔ ﻣـﻦ اﻷرضﰲ اﺗﺠﺎه ﻛﻮﻛﺒﺔ اﻟﺤـﻮت وﻳـﺪور ﺣـﻮل ﻧﺠﻤـﻪ ا ﻀﻴﻒ ﻋﲆ ﻣﺴﺎﻓﺔ ﻗﺮﻳﺒﺔ ﺑﺸﻜﻞ اﺳﺘﺜﻨﺎﺋﻲ أﻗﺮب ﺑﺤﻮاﱄ 12 ا ﻣﺮة ﻣﻦ ﺑ ﺴﺎﻓﺔ ﻋﻄﺎرد و اﻟﺸـﻤﺲ أدى إﱃ ﻣ ـﺎ إﱃ ﺗﺴــﺨ ﻏﻼﻓ ـﻪ اﻟﺠﻮي إﱃ درﺟﺔ ﻋﺎﻟﻴﺔ 2000 درﺟﺔ ﻣﺌﻮﻳـﺔ وﻗﺪ أدت درﺟﺎت اﻟﺤﺮارة اﻟﻘﺼﻮى ﻫـﺬه إﱃ اﻟﻜﻮﻛﺐ " ﻧﻔﺦ" ﻣﺎ أدى إﱃ زﻳﺎدة ﺣﺠﻤﻪ ﺳﺘﺔ أﺿــﻌﺎف ﺣﺠـﻢ ﻛﻮﻛـﺐ ا ﺸـﱰ و ي ﰲ ﻣﺜـﻞ درﺟﺎت اﻟﺤﺮارة ﻫﺬه ﻳﻤﻜﻦ ﻟﻠﻌﻨﺎﴏ ا ﻌﺪﻧﻴﺔ واﻟﺼﺨﺮﻳﺔ اﻟﺘﻲ ﻟﻮﻻ ذﻟﻚ أن ﺗﻈﻞ ﻣﺨﻔﻴـﺔ ﰲ اﻟﻐﻼف اﻟﺠﻮي ﻟﻜﻮﻛﺐ ﻏﺎ زي ﻋﻤﻼق أﺑﺮد أن ﺗﻜﺸﻒ ﻋﻦ ﻧﻔﺴـﻬﺎ وﺑﺎﺳـﺘﺨﺪام ﺗﻠﺴـﻜﻮب ﺟﻴﻤﻴﻨﻲ ﻧﻮرث اﻟﺘﺎﺑﻊ ﺮﺻﺪ ﺟﻴﻤﻴﻨﻲ اﻟـﺪوﱄ اﻟﺬي ﻳﺪﻳﺮه ﻣﺨﺘﱪ ﻧﻮﻳﺮﻻب اﻟﺘﺎﺑﻊ ﺆﺳﺴـﺔ اﻟﻌﻠﻮم اﻟﻮﻃﻨﻴﺔ اﻷﻣﺮﻳﻜﻴـﺔ اﻛﺘﺸـﻒ ﻓﺮﻳـﻖ ____ دوﱄ ﻣﻦ ﻋﻠﻤﺎء اﻟﻔﻠﻚ 11 ﻣﻦ ﻫﺬه اﻟﻌﻨـﺎﴏ ا ﻜﻮﻧﺔ ﻟﻠﺼﺨﻮر ﰲ اﻟﻐﻼف اﻟﺠﻮي ﻟﻠﻜﻮﻛـﺐ WASP-76b . إن وﺟــﻮد ﻫــﺬه اﻟﻌﻨــﺎﴏ وﻛﻤﻴﺎﺗﻬ ـﺎ اﻟﻨﺴــﺒﻴﺔ ﻳﻤﻜــﻦ أن ﻳ ـﻮﻓﺮ رؤى أﺳﺎﺳﻴﺔ ﺣﻮل ﻛﻴﻔﻴﺔ ﺗﺸﻜﻞ اﻟﻜﻮاﻛﺐ اﻟﻐﺎزﻳﺔ اﻟﻌﻤﻼﻗﺔ ﺑﺎﻟﻀﺒﻂ وﻫﻮ أﻣﺮ ﻻ ﻳﺰا ل ﻏ ﻣﺆﻛﺪ ﺣﺘﻰ ﰲ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ وﻧﴩت اﻟﻨﺘـﺎﺋﺞ ﰲ ﻧﻴﺘﴩ ﻣﺠﻠﺔ . ﻣﻨﺬ اﻛﺘﺸﺎﻓﻪ ﰲ ﻋﺎم 2013 ﺑﻮاﺳﻄﺔ ﺑﺮﻧﺎﻣﺞ اﻟﺒﺤﺚ واﺳﻊ ا ﻟـﺰاوي ﺠﺎل ا ﻋـﻦ اﻟﻜﻮاﻛـﺐ ) WASP ( ﻗـﺎم اﻟﻌﺪﻳـﺪ ﻣـﻦ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ ﺑﺪراﺳﺔ ذﻟﻚ اﻟﻜﻮﻛﺐ اﻟﻐﺎﻣﺾ WASP-76b وﻗﺪ أدت ﻫﺬه اﻟﺪراﺳﺎت إﱃ ﺗﺤﺪﻳﺪ اﻟﻌﻨـﺎﴏ ا ﺨﺘﻠﻔﺔ ا ﻮﺟﻮدة ﰲ اﻟﻐﻼف اﻟﺠﻮي اﻟﺴﺎﺧﻦ ﻟﻠﻜﻮﻛﺐ اﻟﻨﺠﻤﻲ . ﻧﴩت دراﺳﺔ ﰲ ﻣﺎرس 2020 ﺧﻠﺺ ﻓﺮﻳـﻖ اﻟﺪراﺳﺔ إﱃ أﻧﻪ ﻣﻦ ا ﻤﻜﻦ أن ﻳﻜـﻮن ﻫﻨـﺎك أﻣﻄﺎر ﺣﺪﻳﺪﻳﺔ ﻋﲆ اﻟﻜﻮﻛﺐ . إدراﻛﺎً ﻟﻬـﺬه اﻟﺪراﺳـﺎت ا ﻮﺟـﻮدة اﺳـﺘﻠﻬﻢ ﺳﺘﻴﻔﺎن ﺑﻴﻠﻴﺘﻴﻴﻪ ﻃﺎﻟﺐ اﻟـﺪﻛﺘﻮراه ﰲ ﻣﻌﻬـﺪ ﺗﺮوﺗﻴﻴﻪ ﻷﺑﺤﺎث اﻟﻜﻮاﻛﺐ اﻟﻨﺠﻤﻴﺔ ﺑﺠﺎﻣﻌـﺔ ﻣﻮﻧﱰﻳﺎل وا ﺆﻟﻒ اﻟﺮﺋﻴ ـ اﻟﺪراﺳـﺔ ﴘ ﻟﻬـﺬه اﺳﺘﻜﺸـﺎف أﴎار ﻫـﺬا اﻟﻜﻮﻛـﺐ اﻟﻨﺠﻤـﻲ اﻟﻐﺮﻳﺐ وﻛﻴﻤﻴـﺎء اﺷـﺘﻌﺎل ﻏﻼﻓـﻪ اﻟﺠـﻮي . ﻓ ﺒﺎﺳﺘﺨﺪام ﺎروون ﻣـ) ﺟﻬﺎز - إﻛـﺲ ﻣـﻦ ( ﻣﺮﺻـﺪ ﺟﻴﻤﻨـﻲ ﻧـﻮرث وﻫـﻲ أداة ﺟﺪﻳـﺪة ﻣﺼــﻤﻤﺔ ﺧﺼﻴﺼــ ﺎً ﻻﻛﺘﺸــﺎف ودراﺳــﺔ اﻟﻜﻮاﻛﺐ اﻟﻨﺠﻤﻴﺔ ﺑ ﻋﺎﻣﻲ 2020 و 2022 رﺻﺪ ﺑﻴﻠﻴﺘﻴﻴﻪ وﻓﺮﻳﻘﻪ اﻟﻜﻮﻛﺐ أﺛﻨﺎء ﻣـﺮوره أﻣﺎم ﻧﺠﻤﻪ ﰲ ﺛﻼث ﻣﻨﺎﺳﺒﺎت ﻣﻨﻔﺼﻠﺔ وﻗـﺪ ﻛﺸﻔﺖ ﻫﺬه اﻷرﺻﺎد اﻟﺠﺪﻳﺪة ﻋﻦ ﻋـﺪد ﻣـﻦ اﻟﻌﻨﺎﴏ ا ﻜﻮﻧﺔ ﻟﻠﺼﺨﻮر ﰲ اﻟﻐﻼف اﻟﺠـﻮي ﻟﻠﻜﻮﻛــﺐ WASP-76b ﻣﻨﻬــﺎ اﻟﺼــﻮدﻳﻮم واﻟﺒﻮﺗﺎﺳﻴﻮم واﻟﻠﻴﺜﻴـﻮم واﻟﻨﻴﻜـﻞ وا ﻨﻐﻨﻴـﺰ واﻟﻜﺮوم وا ﻐﻨﻴﺴﻴﻮم وا ﻟﻔﺎﻧﺎدﻳﻮم واﻟﺒﺎرﻳﻮم واﻟﻜﺎﻟﺴﻴﻮم واﻟﺤﺪﻳﺪ ا ﻜﺘﺸﻒ . ﺳﺎﺑﻘﺎً - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 3 إن