オリオン大星雲　「息のむ」最新画像　ウェッブ宇宙望遠鏡が撮影

【ワシントンＡＦＰ＝時事】国際研究チームは１２日、ジェームズ・ウェッブ宇宙望遠鏡が撮影した「オリオン大星雲」の初画像を公開した。研究チームからは「息をのむ」画像との声も上がった。（写真はジェームズ・ウェッブ宇宙望遠鏡の近赤外線カメラ「ＮＩＲＣａｍ」が捉えた、オリオン大星雲の内部領域）
　オリオン座の方向に、地球から約１３５０光年の距離にあるこの星形成領域は、４５億年以上前に太陽系が形成された状況と類似した環境にある。
　太陽系進化の最初の数百万年間に起きた事象への理解を深めるために、天文学者らはこの領域に関心を向けている。
　星雲は大量の塵（ちり、固体微粒子）に覆い隠されており、可視光の望遠鏡では観測できないが、ウェッブ宇宙望遠鏡は赤外線を使用するため、この塵を透過しての観測が行える。
　今回の観測では、最小で４０天文単位（ＡＵ＜１ＡＵは太陽地球間の平均距離＞）までの注目すべき構造が多数存在することが明らかになった。４０ＡＵは、太陽系の大きさに相当する。
　こうした構造の一つに、星間物質が密集したフィラメントがある。フィラメントの中では、新しい世代の恒星や原始恒星系が形成される可能性がある。原始恒星系は中心の原始星とそれを取り巻く塵とガスの円盤で構成され、この円盤の中で惑星が形成される。
　国際研究チームの一人である米ミシガン大学の天文学者エドウィン・バーギン氏は「星形成のサイクル全般に関する理解が得られると期待している」と述べている。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2022/09/13-14:34）

The wall of dense gas and dust resembles a massive winged creature, its glowing maw lit by a bright star as it soars through cosmic filaments.
An international research team on Monday revealed the first images of the Orion Nebula captured with the James Webb Space Telescope, leaving astronomers blown away.
The stellar nursery is situated in the constellation Orion, 1,350 light-years away from Earth, in a similar setting in which our own solar system was birthed more than 4.5 billion years ago.
Astronomers are interested in the region to better understand what happened during the first million years of our planetary evolution.
The images were obtained as part of the Early Release Science program and involved more than 100 scientists in 18 countries, with institutions including the French National Centre for Scientific Research (CNRS), Western University in Canada, and the University of Michigan.
We are blown away by the breathtaking images of the Orion Nebula, Western University astrophysicist Els Peeters said in a statement.
These new observations allow us to better understand how massive stars transform the gas and dust cloud in which they are born, she added.
Nebulas are obscured by large amounts of dust that made it impossible to observe with visible light telescopes, such as the Hubble Space Telescope, Webb's predecessor.
Webb however operates primarily in the infrared spectrum, penetrating the dust.
This revealed numerous spectacular structures, down to the scale of 40 astronomical units, or the size of our solar system.
These include dense filaments of matter, which could birth new generations of stars, as well as forming stellar systems that consist of a central proto-star surrounded by a disc of dust and gas, in which planets form.
We hope to gain understanding about the entire cycle of star birth, said Edwin Bergin, University of Michigan chair of astronomy and a member of the international research team.
In this image we are looking at this cycle where the first generation of stars is essentially irradiating the material for the next generation. The incredible structures we observe will detail how the feedback cycle of stellar birth occurs in our galaxy and beyond.
Webb is the most powerful space telescope ever built, boasting a primary mirror measuring 6.5 meters (more than 21 feet) that is made up of 18 hexagonal, gold-coated segments, as well as a five-layer sunshield the size of a tennis court.