জেমস ওয়েব স্পেস টেলিস্কোপ (জেডব্লিউএসটি): প্রারম্ভিক মহাবিশ্বের অধ্যয়নের জন্য নিবেদিত প্রথম স্পেস অবজারভেটরি

জেমস ওয়েব স্পেস টেলিস্কোপ (JWST) will specialise exclusively in infrared astronomy to study early বিশ্ব. It will search for optical/infrared signals from the early নক্ষত্র and galaxies formed in the বিশ্ব soon after the Big Bang for a better understanding of the formation and evolution of galaxies and the formation of নক্ষত্র এবং অস্থিরমতি সিস্টেম। জেডব্লিউএসটি will also study অস্থিরমতি systems and the origins of life. The much-awaited জেডব্লিউএসটি is now scheduled to be launched on 18 December 2021.  

Usually, one focusses a telescope at a target to observe. But at times you deliberately focus on nothing and that change the course of a field of study. Decision to focus হাবল স্থান telescope on nothing in the hitherto unexplored fields in the sky was one such incident that changed the course of astronomy. 

অনেক যুগান্তকারী অর্জনের মধ্যে হাবল স্থান Telescope (HST), the deep field images taken over the course of 10 days in 1995 when it captured about 3000 images of galaxies at different stages of stellar evolution has revolutionised astronomy and changed our understanding of the বিশ্ব.  

These deep field images were formed by the light that had travelled from the remotest locations of the বিশ্ব for billions of light years through the expanding বিশ্ব and had reached Earth now to be captured by the হাবল telescope after originally emanating from the early নক্ষত্র and galaxies formed soon after Big Bang about 13 billion years ago. So, as such deep field images denoted early নক্ষত্র and galaxies as they were then billions of years ago. This was truly remarkable feat.  

But, this technique of capturing primordial optical signals for developing understanding of early বিশ্ব could not be an effective methodological tool due to the fact discovered in 1929 by Edwin হাবল যে বিশ্ব is expanding and all galaxies are moving away from each other as evidenced by the redshift of ছায়াপথ’s spectrum to higher wavelengths in infrared (IR) region. But the হাবল telescope is equipped to observe in UV, visible and near-infrared region hence the need for an exclusive infrared অবজারভেটরি in স্থান.  

সার্জারির জেমস ওয়েব স্পেস টেলিস্কোপ (JWST) is thus a successor to the হাবল স্থান telescope (HST) in the sense that the জেমস ওয়েব telescope aims to carry forward the হাবল telescope’s legacy in the area of study of early বিশ্ব. জেডব্লিউএসটি will operate exclusively in infrared astronomy and has following four key goals: 

এসব কারণে, জেডব্লিউএসটি needed to be different from হাবল telescope in design and operation. It is a reflecting telescope designed to capture near-infrared radiations from ultra-deep fields with a large origami-style mirror that makes it 100 times more powerful than হাবল। আসলে, জেডব্লিউএসটি বৃহত্তম স্থান telescope ever. To maintain its unprecedented infrared sensitivity, জেডব্লিউএসটি has protection from infrared contamination from sun through a highly effective 5-layer sunshield. Further, to help maintain its very low operating temperature of 50 Kelvin (-223° C or -370° F), JWST will be placed in an কক্ষপথ around the sun in the cold shadow of Earth all the time near the second Lagrange point (L2) of the Earth-Sun system at a distance of about 1.5 million km from Earth.  

এর বসানো জেডব্লিউএসটি near far off Sun-Earth system L2 কক্ষপথ means, unlike হাবল telescope which received several repairs and maintenance in the স্থান, জেডব্লিউএসটি will be completely on its own after launch therefore there is no scope of any error at all. Perhaps this explains why launch of জেডব্লিউএসটি is almost eternally delayed.  

এখন, জেডব্লিউএসটি is planned to be launched on 18 December 2021.  

As on 02 November 2021, জেডব্লিউএসটি has already safely arrived at its launch site in French Guiana and the technical team is preparing for lift off on 18 December.  

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সোর্স:  

1. NASA 2021. Webb telescope – The Road to Launch and Beyond for NASA’s James Webb স্থান Telescope. Posted 02 November 2021. Available online at https://www.nasa.gov/feature/goddard/2021/the-road-to-launch-and-beyond-for-nasa-s-james-webb-space-telescope  

2. নাসা। JWST - ওয়েব সম্পর্কে সাধারণ প্রশ্ন। অনলাইনে উপলব্ধ https://www.jwst.nasa.gov/content/about/faqs/faq.html  

3. নাসা। JWST - মূল তথ্য। অনলাইনে উপলব্ধ https://jwst.nasa.gov/content/features/keyFactsInternational/ 

1. ESA. বিজ্ঞান ও অনুসন্ধান। ওয়েব - আরও দেখা হচ্ছে। অনলাইনে উপলব্ধ https://www.esa.int/Science_Exploration/Space_Science/Webb 

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