Humans Watched This Supernova Explode Nearly a Millennium Ago. Now You Can See It in High Definition

Astronomers have obtained the most detailed image to date of the Pa 30 nebula, the remnants of a supernova famous for having likely been observed and documented from Earth during the Middle Ages. Now, the new photograph reveals structures that had long gone unnoticed.

天文学家获得了迄今为止最详细的 Pa 30 星云图像，这是超新星的残骸，因极有可能在中世纪被地球上的人们观测并记录下来而闻名。现在，这张新照片揭示了长期以来未被注意到的结构。

Previous images of the explosion’s remnants had also captured a sphere of long, filament-like strands of matter that collectively resemble fireworks or a dandelion. The new observations, made with the Gemini North telescope in Hawaii, revealed about 10 times more structures than any previous glimpses of the supernova remnant. With this resolution, researchers can now see that these filaments are not continuous as they had previously appeared. Instead, they’re shaped more like beads on a string, made up of pearl-like knots of gas of relatively uniform size.

之前对爆炸残骸的图像也捕捉到了一个由长丝状物质组成的球体，它们看起来像烟花或蒲公英。利用夏威夷的双子座北望远镜进行的新观测，揭示出的结构比以往任何对该超新星残骸的观测都要多出约 10 倍。凭借这种分辨率，研究人员现在可以看到，这些丝状物并非此前看起来的那样是连续的。相反，它们的形状更像是一串珠子，由大小相对均匀的珍珠状气体结组成。

These “cosmic pearls” are, in fact, enormous. According to the study published in The Astrophysical Journal, each bead measures about four light-days in diameter. “The planetary region of our solar system could fit in each knot about 10 times with room to spare,” Ilaria Caiazzo, a coauthor of the study, said in a press release. “The knots are quite strikingly uniform. We are excited to try to model them.”

这些“宇宙珍珠”实际上非常巨大。根据发表在《天体物理学杂志》上的研究，每颗“珠子”的直径约为 4 光天。“我们太阳系的行星区域可以放入每个结中约 10 次，而且还有剩余空间，”该研究的合著者伊拉里亚·卡亚佐（Ilaria Caiazzo）在新闻稿中说。“这些结非常惊人地均匀。我们很兴奋能尝试为它们建立模型。”

How exactly the pearls formed is not yet entirely clear, though it’s assumed they are concentrations of material ejected during the explosion. What’s strange, however, is their regularity. In the aftermath of a supernova, astronomers expected to find much more oddly shaped accumulations, but the knots are similar in size and appear aligned along the filaments. This peculiar order is a new feature that could help researchers gain a deeper understanding of stellar death.

这些珍珠究竟是如何形成的尚不完全清楚，但推测它们是爆炸过程中喷射出的物质聚集体。然而，奇怪的是它们的规律性。在超新星爆发后，天文学家原本预计会发现形状更加奇特的堆积物，但这些结的大小相似，且似乎沿着丝状物排列。这种奇特的秩序是一个新特征，可能有助于研究人员更深入地了解恒星的死亡。

This image, obtained with the Gemini Multi-Object Spectrograph, shows that the ejecta from the remnant—with its unmistakable fireworks-like shape—form a cascading structure resembling a knot. International Gemini Observatory/NOIRLab/NSF/AURA

这张由双子座多目标光谱仪拍摄的图像显示，来自残骸的喷射物——具有明显的烟花状外观——形成了一种类似于结的级联结构。国际双子座天文台/NOIRLab/NSF/AURA

The Pa 30 nebula is also particularly unusual because the central star isn’t exactly dead. Instead, it’s considered a “zombie star.” Typically, a thermonuclear supernova is the violent death of a star, which is completely destroyed in the explosion. But in rare cases, part of the star may survive, and scientists do not yet fully understand how or why this happens. The unusual structures of Pa 30 could help astronomers reconstruct more precisely how these kinds of detonations occur and how zombie stars can live on afterward.

Pa 30 星云也特别不同寻常，因为其中心恒星并没有完全死亡。相反，它被认为是一颗“僵尸恒星”。通常，热核超新星是一颗恒星的剧烈死亡，它会在爆炸中彻底毁灭。但在极少数情况下，恒星的一部分可能会幸存下来，科学家们尚不完全了解这是如何或为何发生的。Pa 30 的异常结构可能有助于天文学家更精确地重建这类爆炸是如何发生的，以及僵尸恒星在爆炸后如何继续存在。

All of this has been discovered because scientists seem to have a bit of a crush on Pa 30. Few astronomical structures connect modern observation so directly with human accounts from more than eight centuries ago. The nebula matches the records left by Chinese and Japanese astronomers in 1181, who described the appearance of a new star in the sky that remained visible for several months. At the time, it was impossible to know that they were witnessing the aftermath of a massive stellar explosion. Centuries later, scientists linked that event to the supernova that gave rise to Pa 30.

所有这些发现都是因为科学家们似乎对 Pa 30 情有独钟。很少有天文结构能将现代观测与八个多世纪前的人类记录如此直接地联系起来。该星云与 1181 年中国和日本天文学家留下的记录相吻合，他们描述了天空中出现了一颗新星，并持续可见了几个月。当时，他们不可能知道自己正在目睹一场巨大恒星爆炸的余波。几个世纪后，科学家们将该事件与产生 Pa 30 的超新星联系了起来。

This story originally appeared on WIRED en Español and has been translated from Spanish.

本文最初发表于《连线》西班牙语版，由西班牙语翻译而来。