NASA·APOD每日天文一图2022.6.7 [超高清]

天空中的龙！

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.  

龙在天空的祭坛上战斗吗？虽然看起来可能是这样，但这些龙是由稀薄的气体和尘埃构成的幻觉。发光云所在的发射星云NGC 6188位于南天星座Ara（圣坛）的一个可见光波段看不见的大分子云边缘，距离我们约4000光年远。仅在几百万年前，嵌入Ara OB1星团的巨大年轻恒星就在该区域形成，塑造出黑暗的形状，并通过恒星风和强烈的紫外线辐射为星云发光提供能量。最近的恒星形成本身很可能是由前几代大质量恒星的风和超新星爆炸引发的，这些爆炸扫过并压缩了分子气体。在这张右下角可见的宇宙画布上，加入NGC 6188的是罕见的发射星云NGC 6164，也是由该地区的一颗大质量O型恒星创建的。与许多行星状星云的外观相似，NGC 6164引人注目的对称气体罩和微弱的光晕围绕着其底部边缘附近明亮的中心恒星。这张令人印象深刻的大视场跨度超过2度（四个满月），相当于NGC 6188估计距离超过150光年。