Ou4: 巨乌贼星云

Ou4: 巨乌贼星云

Ou4: The Giant Squid Nebula
Image Credit & Copyright: Alex Linde

Explanation: Squids on Earth aren’t this big. This mysterious squid-like cosmic cloud spans nearly three full moons on planet Earth’s sky. Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula’s bipolar shape is distinguished here by the telltale blue emission from doubly ionized oxygen atoms. Though apparently surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine. Still, one investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, the cosmic squid would represent a spectacular outflow of material driven by a triple system of hot, massive stars, cataloged as HR8119, seen near the center of the nebula. If so, this truly giant squid nebula would physically be over 50 light-years across.

Tomorrow’s picture: thunder jets

Ou4: 巨乌贼星云
影像提供与版权: Alex Linde

说明: 地球上的乌贼个头并不大。地球的天空中，有这团跨幅将近3个满月宽度的神秘乌贼状星云。由法国天文摄影师奥特斯 发现于2011年的乌贼星云（Ou4），其双极瓣结构，因这幅影像所记录的特征性双电离氧原子的泛蓝辐射而变得清晰可辨。乌贼星云虽然四周看似环绕着泛红的氢辐射区Sh2-129，然而其真实的距离及本质至今仍难以确认。不过，不久前的一项研究指出，Ou4的确是位在距离约2,300光年远的发射星云SH2-129之内。在此情况下，这尾宇宙级的乌贼，可能是从一个炽热大质量的三合星系统 （编录号HR8119）外泛的大片物质。如此为真，庞大的乌贼星云之身宽超过50光年。

明日的图片: thunder jets