Free Astronomy Magazine September-October 2023 ARABIC VERSION

32 ASTRO PUBLISHING ‘Smiling cat’ nebula captured in new image by ESO − Juan Carlos Muñoz Mateos his cloud of orange and red, part of the Sh2-284 nebula, is shown here in spectacular de- tail using data from the VLT Survey Telescope, hosted by the European Southern Observatory (ESO). This nebula is teeming with young stars, as gas and dust within it clumps to- gether to form new suns. If you take a look at the cloud as a whole, you might be able to make out the face of a cat, smiling down from the sky. The Sh2-284 stellar nursery is a vast region of dust and gas and its brightest part, visible in this image, is about 150 light-years (over 1,400 trillion kilometers) across. It’s located some 15,000 light-years away from Earth in the constellation Monoc- eros. Nestled in the centre of the brightest part of the nebula — right under the ‘cat’s nose’ — is a cluster of young stars known as Dolidze 25, which produces large amounts of strong radiation and winds. The ra- diation is powerful enough to ionise the hydrogen gas in the cloud, thereby producing its bright orange and red colours. It’s in clouds like this that the building blocks for new stars reside. The winds from the central cluster of stars push away the gas and dust in the nebula, hollowing out its centre. As the winds encounter denser pockets of material, these offer more resistance meaning that the areas around them are eroded away first. This creates several pillars that can be seen along the edges of Sh2- 284 pointing at the centre of the nebula, such as the one on the right- hand side of the frame. While these pillars might look small in the image, they are in fact several light-years wide and contain vast amounts of gas and dust out of which new stars form. This image was created using data from the VLT Survey Telescope (VST), which is owned by The National In- stitute for Astrophysics in Italy, INAF, and is hosted at ESO’s Paranal Obser- vatory in Chile. The VST is dedicated to mapping the southern sky in visi- ble light and makes use of a 256-mil- lion-pixel camera specially designed for taking very wide-field images. This image is part of the VST Photo- metric H α Survey of the Southern Galactic Plane and Bulge (VPHAS+), which has studied some 500 million objects in our home galaxy, helping us better understand the birth, life, and eventual death of stars within our Milky Way.     SEPTEMBER-OCTOBER 2023 : ﻘﻠﻢ ﺧﻮان ﺎرﻟﻮسﻣﻮﻧﻴﻮزﻣﺎﺗﻴﻮس اﻟﻤﺮﺻﺪ اﻷوروﺑﻲ اﻟ ـ ﺠﻨﻮﺑﻲ ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ﻈﻬﺮ ـــ ﺗ ﻫﺬه اﻟﺴﺤﺎ ﺑﺔ ذات اﻟﻠﻮن اﻟﱪﺗﻘﺎﱄ واﻷﺣﻤﺮ وﻫﻲ ﺟﺰء ﻣـﻦ ﺳـﺪﻳﻢ Sh2-284 ﻫﻨﺎ ﺑﺘﻔﺎﺻﻴﻞ ﻣﺬﻫﻠﺔ ﺑﺎﺳﺘﺨﺪام ﺑﻴﺎﻧﺎت ﻣﻦ ﺗﻠﺴﻜﻮب ا ﺴﺢ اﻟﻔﻠﻜﻲ ) ( ﰲ إل ﺗﻲ ا ﻤﻠـﻮك ﻟﻠﻤﻌﻬﺪ اﻟﻮﻃﻨﻲ ﻟﻠﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ ﰲ إﻳﻄﺎﻟﻴﺎ و اﻟﺬي ﻳﺴﺘﻀﻴﻔﻪ ا ﺮﺻﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ . ﰲ ﺗﺸﻴﲇ ﻳﻌﺞ ﻫﺬا اﻟﺴﺪﻳﻢ ﺑﺎﻟﻨﺠﻮم اﻟ ﻴﺎﻓﻌﺔ ﺣﻴﺚ ﻳﺘﺠﻤﻊ اﻟﻐﺎز واﻟﻐﺒﺎر ﺑﺪاﺧﻠﻪ ﻟﺘﻜـﻮﻳﻦ ﻧﺠﻮم إذا أ . ﺟﺪﻳﺪة ﻟﻘﻴﺖ ﻧﻈﺮة ﻋﲆ اﻟﺴﺤﺎﺑﺔ ﻛﻜﻞ ﻓﻘﺪ ﺗﺘﻤﻜﻦ ﻣﻦ رؤﻳﺔ وﺟﻪ ﻗﻂ ﺒﺘﺴﻢ ﻳ . إن اﻟﺤ ﻨﺿﺎ ﺔ اﻟﻨﺠﻤ ﻴﺔ Sh2-284 ﻋﺒﺎرة ﻋـ ﻦ ﻣﻨﻄﻘﺔ ﺷﺎﺳﻌﺔ ﻣﻦ اﻟﻐﺒﺎر واﻟﻐـﺎز ﻠـﻎ وﻳﺒ ﻋﺮض اﻟﺠﺰء اﻷﻛﺜﺮ ﺳﻄﻮﻋﺎً ﻣﻨﻬﺎ اﻟﻈـﺎﻫﺮ ﰲ ﻫﺬه اﻟﺼﻮرة ﺣـﻮاﱄ 150 ﺳـﻨﺔ ﺿـﻮﺋﻴﺔ ) أﻛﺜﺮ ﻣﻦ 1400 ﺗﺮﻳﻠﻴﻮن ﻛﻴﻠﻮﻣﱰ ( وﺗﻮﺟـﺪ ﻋﲆ ﻣﺴﺎﻓﺔ ﺣﻮاﱄ 15000 ﺳﻨﺔ ﺿﻮﺋﻴﺔ ﻣﻦ اﻷرضﰲ ﻛﻮﻛﺒـﺔ وﺣﻴـﺪ اﻟﻘـﺮن . ﻳﻮﺟـﺪ ﰲ وﺳﻂ اﻟﺠﺰء اﻷﻛﺜﺮ ﺳـﻄﻮﻋ ﺎً ﻣـﻦ اﻟﺴـﺪﻳﻢ " ﺗﺤﺖ أﻧﻒ اﻟﻘﻂ " - ﻣﺒﺎﴍة ﻣﺠﻤﻮﻋﺔ ﻣـﻦ اﻟﻨﺠﻮم اﻟﺸﺎﺑﺔ ا ﺴﻤﺎة Dolidze 25 واﻟﺘﻲ ﺗﻨﺘﺞ ﻛﻤﻴﺎت ﻛﺒ ة ﻣـﻦ اﻟﺮﻳـﺎح و اﻹﺷـﻌﺎع اﻟﻘﻮي ﺑﻤﺎ ﻳﻜﻔﻲ ﻟﺘﺄﻳ ﻏـﺎ ز اﻟﻬﻴـﺪروﺟ ا ﻮﺟﻮد ﰲ اﻟﺴﺤﺎﺑﺔ و إ ﻧﺘﺎج أﻟﻮ اﻧﻪ اﻟﱪﺗﻘﺎﻟﻴﺔ واﻟﺤﻤﺮاء اﻟﺰاﻫﻴﺔ و ، ﰲ ﻣﺜـﻞ ﻫـﺬه اﻟﺴـﺤﺐ ﺗﻮﺟﺪ اﻟﻠﺒﻨﺎت اﻷﺳﺎﺳﻴﺔ ﻟﻠﻨﺠﻮم اﻟﺠﺪﻳﺪة . ﺗﺪﻓﻊ اﻟﺮﻳﺎح اﻟﻘﺎدﻣﺔ ﻣﻦ اﻟﻌﻨﻘﻮد اﻟﻨﺠﻤـﻲ ا ﺮﻛﺰي اﻟﻐﺎز واﻟﻐﺒـﺎر ا ﻮﺟـﻮد ﰲ اﻟﺴـﺪﻳﻢ ﻣﻤﺎ ﻳﺆدي إﱃ ﺗﻔﺮﻳﻎ و ﻣﺮﻛﺰه ﻋﻨﺪﻣﺎ ﺗﻮاﺟـﻪ اﻟﺮﻳﺎح ﺟﻴﻮﺑ ﺎً أﻛﺜﺮ ﻛﺜﺎﻓﺔ ﻣﻦ ا ـﻮاد ﻓﺈﻧﻬـﺎ ﺗﻮﻓﺮ ﻣﻘﺎوﻣﺔ أﻛﱪ ﻣﻤـﺎ ﻳﻌﻨـﻲ أن ا ﻨـﺎﻃﻖ ا ﺤﻴﻄﺔ ﺑﻬﺎ ﺗﺘﺂﻛﻞ أوﻻً ، ﻳﺆدي ﻫﺬا إﱃ إﻧﺸﺎء ﻋﺪة أﻋﻤﺪة ﻳﻤﻜﻦ رؤﻳﺘﻬﺎ ﻋﲆ ﻃﻮل ﺣـﻮاف Sh2-284 ﺗﺸ إﱃ ﻣﺮﻛﺰ اﻟﺴﺪﻳﻢ ﻣﺜﻞ ﺗﻠﻚ ا ﻮﺟﻮدة ﻋﲆ اﻟﺠﺎﻧﺐ اﻷﻳﴪ ﻣﻦ اﻹﻃﺎر . ﰲ ﺣ أن ﻫﺬه اﻷﻋﻤﺪة ﻗﺪ ﺗﺒﺪو ﺻـﻐ ة ﰲ اﻟﺼﻮرة إﻻ أﻧﻬﺎ ﰲ اﻟﻮاﻗﻊ ﻳﺒﻠﻎ ﻋﺮﺿﻬﺎ ﻋﺪة ﺳﻨﻮات ﺿﻮﺋﻴﺔ وﺗﺤﺘﻮي ﻋﲆ ﻛﻤﻴﺎت ﻫﺎﺋﻠﺔ ﻣﻦ اﻟﻐﺎز واﻟﻐﺒﺎر اﻟ ﺬي ﺗﺘﺸﻜﻞ ﻣﻨﻪ اﻟﻨﺠـﻮم اﻟﺠﺪﻳﺪة . ﺗﻢ إﻧﺸﺎء ﻫﺬه اﻟﺼﻮرة ﺑﺎﺳﺘﺨﺪام ﺑﻴﺎﻧﺎت ﻣﻦ ﺗﻠﺴﻜﻮب ا ﺴﺢ اﻟﻔﻠﻜﻲ واﻟـﺬي ﺗــﻢ ﺗﺨﺼﻴﺼـ ﻪ ﻟﺮﺳـﻢ ﺧــﺮاﺋﻂ ا ﻟﺴــﻤﺎء اﻟﺠﻨﻮﺑﻴﺔ ﰲ اﻟﻀﻮء ا ﺮﺋﻲ وﻳﺴﺘﺨﺪم ﻛﺎﻣ ا ﺑﺪﻗﺔ 256 ﻣﻠﻴﻮن ﺑﻜﺴﻞ ﻣﺼﻤﻤﺔ ﺧﺼﻴﺼﺎً ﻻﻟﺘﻘﺎط ﺻﻮر واﺳﻌﺔ اﻟﻨﻄﺎق . ﻫﺬه اﻟﺼﻮرة ﺟــﺰء ﻣــﻦ ا ﺴــﺢ اﻟﻀــﻮﺋﻲ VST H α ﻟﻠﻤﺴــﺘﻮى واﻻﻧﺘﻔــﺎخ ا ﺠ ـﺮي اﻟﺠﻨ ـﻮﺑﻲ ) VPHAS (+ اﻟﺬي درسﺣﻮاﱄ 500 ﻣﻠﻴـﻮن ﺟﺮم ﺳﻤﺎوي ﰲ ﻣﺠﺮﺗﻨﺎ ﻣﻤﺎ ﻳﺴﺎﻋﺪﻧﺎ ﻋـﲆ ﻓﻬﻢ وﻻدة اﻟﻨﺠﻮم وﺣﻴﺎﺗﻬﺎ و ﻣﻮﺗﻬﺎ ﰲ ﻧﻬﺎﻳﺔ ا ﻄﺎف ﺑﺸﻜﻞ أﻓﻀﻞ ﰲ درب اﻟﺘﺒﺎﻧﺔ . - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 3 ﺗُﻈﻬﺮ ﺻﻮرة ﺟﺪ ﺪة ﻟﺴﺪ ﻢ " اﻟﻘﻂاﻟﻤ ﺘﺴﻢ "