NASA·APOD每日天文一图2022.5.28/超高清

Explanation: In 185 AD, Chinese astronomers recorded the appearance of a new star in the Nanmen asterism. That part of the sky is identified with Alpha and Beta Centauri on modern star charts. The new star was visible for months and is thought to be the earliest recorded supernova. This deep image shows emission nebula RCW 86, understood to be the remnant of that stellar explosion. The narrowband data trace gas ionized by the stillexpanding shock wave. Space-based images indicate an abundance of the element iron and lack of a neutron star or pulsar in the remnant, suggesting that the original supernova was Type Ia. Unlike the core collapse supernova explosion of a massive star, a Type Ia supernova is a thermonuclear detonation on a a white dwarf star that accretes material from a companion in a binary star system. Near the plane of our Milky Way galaxy and larger than a full moon on the sky this supernova remnant is too faint to be seen by eye though. RCW 86 is some 8,000 light-years distant and around 100 light-years across.

公元185 年，中国天文学家记录了南门星群中一颗新星的出现，这部分天空在现代星图上被识别为半人马座α和β。这颗新星可见数月之久，被认为是最早记录的超新星。这张深邃的宇宙图像显示了发射星云RCW 86，它被认为是那次恒星爆炸的残余物。天基图像显示残骸中有丰富的铁元素，但没有中子星或脉冲星 ，这表明最初的超新星是Ia型超新星。不同于一颗大质量恒星从核心崩溃的超新星爆炸， Ia型超新星是一颗白矮星上的热核爆炸，它从双星系统中的伴星中吸积物质。RCW 86距离我们约8,000光年，直径约100光年。