天鵝座的宇宙云

These cosmic clouds of gas and dust drift through rich star fields along the plane of our Milky Way Galaxy toward the high flying constellation Cygnus. They’re too faint to be seen with the unaided eye though, even on a clear, dark night. Image data from a camera and telephoto lens using narrowband filters was used to construct this 10 degree wide field of view. The deep mosaic reveals a region that includes star forming dust clouds seen in silhouette against the characteristic glow of atomic hydrogen and oxygen gas. NGC 6888 is the standout emission nebula near the top. Blown by winds from an massive Wolf-Rayet star it’s about 25 light-years across and known as the Crescent Nebula. A faint bluish curl just below center in the frame is also the signature of a Wolf-Rayet star. Burning fuel at a prodigious rate and near the end of their stellar lives, both stars will ultimately go out with a bang in a spectacular supernova explosion. Toward the right, a massive, young O type star powers the glow of Sh2-101, the Tulip Nebula.

這些氣體與塵埃云，漂流在銀河盤面天鵝座方向的富星野里。不過縱然在漆黑清朗的夜晚，它們還是過于昏暗肉眼不得見。上面這片寬10度的視野，建構(gòu)自配備窄波段濾鏡的相機(jī)和長(zhǎng)焦鏡頭所記錄的影像數(shù)據(jù)。這幅深空組合影像所呈現(xiàn)的此區(qū)景觀，包括以發(fā)出原子氫和氧特征輝光的云氣為背景之剪影狀恒星形成塵埃云。其中，最吸睛的是位在影像頂緣附近的發(fā)射星云NGC 6888。寬約25光年亦名為NGC 6888的眉月星云，是個(gè)由大質(zhì)量沃夫-瑞葉型恒星之恒星風(fēng)所吹出的氣殼云。影像中下方的暗淡泛藍(lán)光弧，為另一顆沃夫-瑞葉型恒星所造成的特征天體。以驚人速率消耗核燃料，處在它們生命的終點(diǎn)附近的這二顆恒星，最后會(huì)以壯觀的超新星爆炸謝幕。此外在影像右側(cè)，還可見到因大質(zhì)量年輕O型星之驅(qū)動(dòng)而發(fā)光的Sh2-101（郁金香星云）。