天空中的龍！

Do dragons fight on the altar of the sky? Although it might appear that way, these dragons are illusions made of thin gas and dust. The emission nebula NGC 6188, home to the glowing clouds, is found about 4,000 light years away near the edge of a large molecular cloud unseen at visible wavelengths, in the southern constellation Ara (the Altar). Massive, young stars of the embedded Ara OB1 association were formed in that region only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions, from previous generations of massive stars, that swept up and compressed the molecular gas. Joining NGC 6188 on this cosmic canvas, visible toward the lower right, is rare emission nebula NGC 6164, also created by one of the region's massive O-type stars. Similar in appearance to many planetary nebulae, NGC 6164's striking, symmetric gaseous shroud and faint halo surround its bright central star near the bottom edge. This impressively wide field of view spans over 2 degrees (four full Moons), corresponding to over 150 light years at the estimated distance of NGC 6188.??

龍?jiān)谔炜盏募缐蠎?zhàn)斗嗎？雖然看起來可能是這樣，但這些龍是由稀薄的氣體和塵埃構(gòu)成的幻覺。發(fā)光云所在的發(fā)射星云NGC 6188位于南天星座Ara（圣壇）的一個(gè)可見光波段看不見的大分子云邊緣，距離我們約4000光年遠(yuǎn)。僅在幾百萬年前，嵌入Ara OB1星團(tuán)的巨大年輕恒星就在該區(qū)域形成，塑造出黑暗的形狀，并通過恒星風(fēng)和強(qiáng)烈的紫外線輻射為星云發(fā)光提供能量。最近的恒星形成本身很可能是由前幾代大質(zhì)量恒星的風(fēng)和超新星爆炸引發(fā)的，這些爆炸掃過并壓縮了分子氣體。在這張右下角可見的宇宙畫布上，加入NGC 6188的是罕見的發(fā)射星云NGC 6164，也是由該地區(qū)的一顆大質(zhì)量O型恒星創(chuàng)建的。與許多行星狀星云的外觀相似，NGC 6164引人注目的對(duì)稱氣體罩和微弱的光暈圍繞著其底部邊緣附近明亮的中心恒星。這張令人印象深刻的大視場(chǎng)跨度超過2度（四個(gè)滿月），相當(dāng)于NGC 6188估計(jì)距離超過150光年。