Free Astronomy Magazine March-April 2024 ARABIC VERSION

A dusty ‘cat’s tail’ in Beta Pictoris system by NASA/ESA/CSA − Abigail Major 5 Christine Pulliam eta Pictoris, a young planetary system located just 63 light- years away, continues to in- trigue scientists even after decades of in-depth study. It possesses the first dust disk imaged around an- other star — a disk of debris pro- duced by collisions between aster- oids, comets, and planetesimals. Observations from NASA’s Hubble Space Telescope revealed a second debris disk in this system, inclined with respect to the outer disk, which was seen first. Now, a team of astronomers using NASA’s James Webb Space Telescope to image the Beta Pictoris (Beta Pic) system has discovered a new, previously unseen structure. The team, led by Isabel Rebollido of the Astrobiology Cen- ter in Spain, used Webb’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) to inves- tigate the composition of Beta Pic’s previously detected main and sec- ondary debris disks. The results ex- ceeded their expectations, revealing a sharply inclined branch of dust, shaped like a cat’s tail, that extends from the southwest portion of the secondary debris disk. “Beta Pictoris is the debris disk that has it all: It has a really bright, close star that we can study very well, and a complex circumstellar environ- ment with a multi-component disk, eta Pictoris image cap- (Mid-Infrared Instrument). A coronagraph (black circle and two small disks) has been used to block the light of the central star. Certain features are highlighted and labeled. A white line traces over the orange main debris disk and is labeled “main disk plane.” A thin blue-green disk is in- clined about five degrees counterclockwise relative to the orange main disk and is highlighted by a blue-green line labeled “extended sec- ondary disk.” Some of the gray material clustered near the center forms a curved feature in the upper right, which is marked with a yel- low line labeled “cat’s tail.” A scale bar shows that the disks of Beta Pic extend for hundreds of astronomical units (AU), where one AU is the average Earth-Sun distance. (In our solar system, Neptune orbits 30 AU from the sun.) In this image, light at 15.5 microns is colored cyan and 23 microns is orange (filters F1550C and F2300C, respectively). [NASA, ESA, CSA, STScI, Christopher Stark (NASA-GSFC), Kellen Lawson (NASA-GSFC), Jens Kammerer (ESO), Marshall Perrin (STScI)] ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 38 " ذﻳﻞﻗﻄﺔ ﻓﻲ ﻏ ﺎري " ﻧﻈﺎم ﺑ ﺘﺎ ﺑ ﻜﺘﻮرﺲ : ﻘﻠﻢ ﺑﻴﺠﻴﻞ ﻣﻴﺠﻮر و ﺑﻮﻟ ﺎم ﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ ﺻــﻮرة ﺑ ﺘــﺎ ﺑ ﻜﺘـــﻮرﺲﺗـــﻢ اﻟﺘﻘﺎﻃﻬـــﺎ ﺑﻮاﺳـﻄﺔ ﺟﻬــﺎز ــﺐ ﻣــ ي ﻟﺘﻠﺴــ ﻮب و ) أداة اﻷﺷــــــــــــــــــــــﻌﺔ ﺗﺤــــــــــــــــــــــﺖ اﻟــــــــــــــــــــــ ـ ﻤﺮاء اﻟﻤﺘﻮﺳــــــــــــــــــــــــﻄﺔ .( ﺗــــــــــــــــــــــــﻢ اﺳــــــــــــــــــــــــﺘﺨﺪام اﻟ ﻮروﻧﺎﻏﺮاف ) داﺋﺮة ﺳﻮداء وﻗﺮﺻ ـ ﻟــــــــــــــــ ( ﺻــــــــــــــــﻐ ﻦ ﺤﺠﺐﺿــــــــــــــــﻮء اﻟــــــــــــــــﻨ ﻢ اﻟﻤﺮﻛــــﺰي . ـــــﺘﻢ ﺗﻤﻴـــــ ﻌـــــﺾ اﻟﻤـــــ ات وﺗﺼـــــﻨ ﻔﻬﺎ . ﻳﺮﺳـــــﻢ ﺧـــــﻂ أﺑـــــ ﺾﻓـــــﻮق ﻗـــــــﺮص ا ﻄـــــــﺎم اﻟﺮ ﺴـــــــﻲ اﻟ ﻘـــــــﺎﻟﻲ و ﺴــــــــــــــــــــــﻤﻰ " ﻣﺴــــــــــــــــــــــﺘﻮى اﻟﻘــــــــــــــــــــــﺮص اﻟﺮ ﺴـــﻲ ." و ﻤﻴـــﻞ ﻗـــﺮصرﻓﻴـــﻊ أﺧﻀـــﺮ ﻣﺰرق ﻨﺤﻮ ﻤﺲدرﺟﺎت ﻋﻜـﺲاﺗﺠـﺎﻩ ﻋﻘــﺎر اﻟﺴــﺎﻋﺔ ﺎﻟﻨﺴـــ ﺔ إﻟــﻰ اﻟﻘـــﺮص ــــــــــﺘﻢ اﻟﺮ ﺴـــــــــﻲ اﻟ ﻘــــــــــﺎﻟﻲ اﻟﻠـــــــــﻮن، و ﺗﻤﻴــــــــــ ﻩ ﺑﺨــــــــــﻂ أﺧﻀــــــــــﺮ أزرق ﺴـــــــــــﻤﻰ " اﻟﻘــــــــﺮص اﻟﺜــــــــﺎﻧﻮي اﻟﻤﻤﺘــــــــﺪ ." ﺗﺸـــــــــ ﻞ ـــــــﺔ اﻟﻤﺘ ﻤﻌـــــــﺔ ﻌـــــــﺾ اﻟﻤـــــــﺎدة اﻟﺮﻣﺎد ــﺔ ﻓــﻲ ـﺎﻟﻘﺮ ﻣــﻦ اﻟﻤﺮﻛــﺰﺳـﻤﺔ ﻣﻨﺤﻨ ﺗﺘﻤــــــ ـــــﺰء اﻟﻌﻠــــــﻮي اﻷ ﻤــــــﻦ، واﻟــــــ ا ﺑﺨــــــﻂ أﺻــــــﻔﺮ ﺴــــــﻤﻰ " ذﻳــــــﻞ اﻟﻘﻄــــــﺔ ." ﻳﻮﺿﺢ ﺷﺮﻂ اﻟﻤﻘ ﺎس أن أﻗﺮا صﺑ ﺘﺎ ــﺚ أن ــﺔ ﺣ ﺑ ﻜﺘــﻮرﺲ ﺗﻤﺘــﺪ ﻟﻤﺌـﺎت اﻟﻮﺣــﺪات اﻟﻔﻠﻜ ــﺔ اﻟﻮﺣــﺪة اﻟﻔﻠﻜ ﻲﻫــ ﻣﺘﻮﺳــﻂ اﻟﻤﺴـﺎﻓﺔ ﺑـ اﻷرضواﻟﺸــﻤﺲ . ) ﻓـﻲ ﻧﻈﺎﻣﻨـﺎ اﻟﺸﻤﺴــﻲ ــﺪورﻧ ﺘـﻮن ﻋﻠــﻰﻣﺴــﺎﻓﺔ 30 ـﺔ ﻣــﻦ اﻟﺸــﻤﺲ وﺣــﺪة ﻓﻠﻜ ( ﻓــﻲﻫــﺬﻩ اﻟﺼــﻮرة ــﻮن اﻟﻀــﻮء ﻳ ﻨﺪ ﻋ 15.5 ﻣ ﻜﺮون ﺎﻟﻠﻮن اﻟﺴﻤﺎويو 23 ﺎ ﻣ ﻜﺮون ﻟ ﻘﺎﻟﻲ ) اﻟﻤﺮﺷﺤﺎن F1550C و F2300C ، ﻋﻠﻰ اﻟﺘﻮاﻟﻲ .( إن ﺑﻴﺘﺎ ﺑﻴﻜﺘﻮرﻳﺲ وﻫﻮ ﻧﻈﺎم ﻛﻮﻛﺒﻲ ﺷـﺎب ﻳﻘﻊ ﻋﲆ ﺑﻌﺪ 63 ﺳﻨﺔ ﺿﻮﺋﻴﺔ ﻓﻘـﻂ ﻻ ﻳـﺰال ﻳﺜ اﻫﺘﻤﺎم اﻟﻌﻠﻤﺎء ﺣﺘـ ﻰ ﺑﻌـﺪ ﻋﻘـﻮد ﻣـﻦ اﻟﺪراﺳﺔ ا ﺘﻌﻤﻘـﺔ ﻓﻬـﻮ ﻳﻤﺘﻠـﻚ أول ﻗـ ﺮص يﻏﺒﺎر ﻳﺘﻢ ﺗﺼﻮﻳﺮه ﺣـﻮل ﻧﺠـﻢ آﺧـﺮ وﻫـﻮ ﻗﺮص ﻣﻦ اﻟﺤﻄﺎم اﻟﻨﺎﺗﺞ ﻋـﻦ اﻻﺻـﻄﺪاﻣﺎت ﺑ اﻟﻜﻮﻳﻜﺒﺎت وا ﺬﻧﺒﺎت واﻟﻜﻮاﻛﺐ اﻟﺼﻐ ة . ﻟﻘﺪ ﻛﺸﻔﺖ اﻷرﺻﺎد اﻟﺘﻲ أﺟﺮاﻫـﺎ ﺗﻠﺴـﻜﻮب ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ ﻋﻦ ﻗﺮصﺣﻄﺎم ﺛﺎنٍ ﰲ ﻫﺬا اﻟﻨﻈﺎم، ﻣﺎﺋـﻞ ﺑﺎﻟﻨﺴـﺒﺔ ﻟﻠﻘـﺮص ـــــ اﻟﺨـﺎرﺟﻲ اﻟـﺬي ﺷـﻮﻫﺪ أوﻻ . اﻵن، اﻛﺘﺸـﻒ ﻓﺮﻳﻖ ﻣﻦ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﺑﺎﺳـﺘﺨﺪام ﺗﻠﺴـﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ ﻟﺘﺼـﻮﻳﺮ ﻧﻈﺎم أﻗﺮاص ﺑﻴ ﺘﺎ ﺑﻴﻜﺘﻮرﻳ ﺲ ﻫﻴﻜﻼً ﺟﺪﻳﺪًا ﻟﻢ ﻳﺴﺒﻖ ﻟـﻪ ﻣﺜﻴـﻞ . اﺳـﺘﺨﺪم اﻟﻔﺮﻳـﻖ ﺑﻘﻴـﺎدة إﻳﺰاﺑﻴﻞ رﻳﺒﻮﻟﻴـﺪو ﻣـﻦ ﻣﺮﻛـ ﺰ ﻋﻠـﻢ اﻷﺣﻴـﺎء اﻟﻔﻠﻜﻲ ﰲ إﺳـﺒﺎﻧﻴﺎ ﻛـﺎﻣ ا ﺗﻠﺴـﻜﻮب وﻳـﺐ ﻧ ﻛﺎم ) ﻛـﺎﻣ ا ﻗﺮﻳﺒـﺔ ﻣـﻦ اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤﺮاء ( ) و ﻣ ي أداة اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء ا ﺘﻮﺳﻄﺔ ( ﻟﻠﺒﺤـﺚ ﰲ ﺗﻜـﻮﻳﻦ أﻗـﺮاص ﺑﻴﺘـﺎ ـــــ ﺑﻴﻜﺘﻮرﻳﺲ اﻟﺘﻲ ﺗـﻢ اﻛﺘﺸـﺎﻓﻬﺎ ﺳـﺎﺑﻘًﺎ ﻣـﻦ اﻟﺤﻄﺎم اﻟﺮﺋﻴﴘ واﻟﺜﺎﻧﻮي . ﻟﻘﺪ ﺗﺠﺎوزت اﻟﻨﺘﺎﺋﺞ ﺗﻮﻗﻌﺎﺗﻬﻢ وﻛﺸﻔﺖ ﻋـﻦ ﻓﺮع ﻣﻦ اﻟﻐﺒﺎر ﻣﺎﺋﻞ ﺑﺸﻜﻞ ﺣﺎد ﻋـﲆ ﺷـﻜﻞ ذﻳﻞ ﻗﻄﺔ ﻳﻤﺘﺪ ﻣﻦ اﻟﺠﺰء اﻟﺠﻨﻮﺑﻲ اﻟﻐﺮﺑﻲ ﻣﻦ ﻗﺮص اﻟﺤﻄﺎم اﻟﺜﺎﻧﻮي . ﺑﻴﺘﺎ " ﺑﻴﻜﺘﻮرﻳﺲ " ﻫﻮ ﻗﺮص اﻟﺤﻄـﺎم اﻟـﺬي ﻳﺤﺘﻮي ﻋﲆ ﻛﻞ ﳾء : إﻧﻪ ﻳﺤﺘﻮي ﻋـﲆ ﻧﺠـﻢ ﻻ ﻣﻊ وﻗﺮﻳﺐ ﺣﻘﺎً ﻳﻤﻜﻨﻨﺎ دراﺳﺘﻪ ﺟﻴﺪ اً وﺑﻴﺌﺔ ﻣﺤﻴﻄﻴﺔ ﻣﻌﻘﺪة ﻣﻊ ﻗﺮصﻣﺘﻌﺪد ا ﻜﻮﻧﺎت . - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 4