Free Astronomy Magazine September-October 2024

A Plethora of carbon molecules around young star byNASA/ESA/CSA BethanyDowner ChristinePulliam n international team of as- tronomers has used NASA’s JamesWebbSpace Telescope to study the disk of gas and dust around a young, very low-mass star. The results reveal the largest num- ber of carbon-containing molecules seen to date in such a disk. These findingshaveimplicationsforthe potentialcompositionofanyplanets that might form around this star. Rocky planets are more likely than gas giants to form around low-mass stars, making them the most com- mon planets around the most com- mon stars in our galaxy. Little is known about the chemistry of such worlds,whichmaybesimilartoor verydifferentfromEarth.Bystudy- ingthedisksfromwhichsuchplan- ets form, astronomers hope to betterunderstandtheplanetforma- tionprocessandthecompositionsof the resulting planets. Planet-forming disks around very low-mass stars are difficult to study becausetheyaresmallerandfainter SEPTEMBER-OCTOBER2024 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 14 ـــــﺎتﻫﺎﺋﻠـــــﺔ ﻤ ﻣـــــﻦﺟﺰ ﺌـــــﺎت اﻟﻜﺮ ﻮنﺣﻮل ﻧ ﻢ ﺷﺎب : ﻘﻠﻢ ﺑﻮﻟ ﺎم ﺑ ﺜﺎﻧﻲداوﻧﺮوﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ اﺳـﺘﺨﺪم ﻓﺮﻳـﻖ دوﱄ ﻣـﻦ ﻋﻠﻤـﺎء اﻟﻔﻠــﻚ ﺗﻠﺴﻜﻮب ﺟـﻴﻤﺲ وﻳـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟ ﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ ﻟﺪراﺳﺔ ﻗﺮص اﻟﻐـﺎز واﻟﻐﺒـﺎر ﺣﻮل ﻧﺠﻢ ﺷﺎب ﻣﻨﺨﻔﺾ اﻟﻜﺘﻠـﺔ ﻟﻠﻐﺎﻳـﺔ . وﺗﻜﺸﻒ اﻟﻨﺘﺎﺋﺞ ﻋﻦ أﻛﱪ ﻋﺪد ﻣﻦ اﻟﺠﺰﻳﺌﺎت ا ﺤﺘﻮﻳﺔ ﻋﲆ اﻟﻜﺮﺑﻮن اﻟﺘﻲ ﺷﻮﻫﺪت ﺣﺘـﻰ اﻵن ﰲ ﻣﺜﻞ ﻫﺬا اﻟﻘﺮص . ﻫﺬه اﻟﻨﺘـﺎﺋﺞ ﻟﻬـﺎ آﺛﺎر ﻋﲆ اﻟﱰﻛﻴﺐ ا ﺤﺘﻤﻞ ﻷي ﻛﻮاﻛـﺐ ﻗـﺪ ـــ ﺗﺘﺸﻜﻞ ﺣﻮل ﻫﺬا اﻟـﻨﺠﻢ . ﻣـﻦ ا ـﺮﺟﺢ أن ﺗﺘﺸﻜﻞ اﻟﻜﻮاﻛـﺐ اﻟﺼـﺨﺮﻳﺔ ﺣـﻮل ﻧﺠـﻮم ﻣﻨﺨﻔﻀﺔ اﻟﻜﺘﻠﺔ أﻛﺜﺮ ﻣﻦ اﻟﻜﻮاﻛﺐ اﻟﻐﺎزﻳﺔ اﻟﻌﻤﻼﻗﺔ، ﻣﻤﺎ ﻳﺠﻌﻠﻬﺎ أﻛﺜﺮ اﻟﻜﻮاﻛﺐ ﺷﻴﻮﻋًﺎ ﺣﻮل اﻟﻨﺠﻮم اﻷﻛﺜﺮ ﺷـﻴﻮﻋًﺎ ﰲ ﻣﺠﺮﺗﻨـﺎ ﻻ . ﻳُﻌﺮف ﺳﻮى ا ﻟﻘﻠﻴﻞ ﻋﻦ ﻛﻴﻤﻴﺎء ﻣﺜـﻞ ﻫـﺬه اﻟﻌ ـﻮاﻟﻢ واﻟﺘــﻲ ﻗ ـﺪ ﺗﻜ ـﻮن ﻣﺘ ﺸ ـﺎﺑﻬﺔ أو ﻣﺨﺘﻠﻔـﺔ ﺗﻤﺎﻣـﺎً ﻋـﻦ اﻷرض وﻣـﻦ ﺧـﻼ ل ــــــ دراﺳﺔ اﻷﻗﺮاص اﻟﺘﻲ ﺗﺘﺸﻜﻞ ﻣﻨﻬﺎ ﻣﺜﻞ ﻫﺬه اﻟﻜﻮاﻛﺐ، ﻳﺄﻣﻞ اﻟﻔﻠﻜﻴـﻮن ﰲ ﻓﻬـﻢ ﻋﻤﻠﻴـﺔ ﺗﻜﻮﻳﻦ اﻟﻜﻮاﻛﺐ وﺗﺮﻛﻴﺐ اﻟﻜﻮاﻛﺐ اﻟﻨﺎﺗﺠـﺔ ﺑﺸﻜﻞ أﻓﻀﻞ . ﻣـﻦ اﻟﺼــﻌﺐ دراﺳـﺔ اﻷﻗ ـﺮاص ا ﻜﻮﻧ ـﺔ ﻟﻠﻜﻮاﻛــﺐ ﺣــﻮل اﻟﻨﺠــﻮم ذات اﻟﻜﺘﻠــﺔ ا ﻨﺨﻔﻀﺔ اً ﺟﺪ ﻷﻧﻬﺎ أﺻـﻐﺮ ﺣﺠﻤـ ﺎً وأﻛﺜـﺮ ﺧﻔﻮﺗًﺎ ﻣﻦ اﻷﻗﺮاص ا ﻮﺟﻮدة ﺣﻮل اﻟﻨﺠﻮم - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 4