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，中國天文學(xué)家記錄了南門星群中一顆新星的出現(xiàn)，這部分天空在現(xiàn)代星圖上被識別為半人馬座α和β。這顆新星可見數(shù)月之久，被認(rèn)為是最早記錄的超新星。這張深邃的宇宙圖像顯示了發(fā)射星云RCW 86，它被認(rèn)為是那次恒星爆炸的殘余物。天基圖像顯示殘骸中有豐富的鐵元素，但沒有中子星或脈沖星?，這表明最初的超新星是Ia型超新星。不同于一顆大質(zhì)量恒星從核心崩潰的超新星爆炸， Ia型超新星是一顆白矮星上的熱核爆炸，它從雙星系統(tǒng)中的伴星中吸積物質(zhì)。RCW 86距離我們約8,000光年，直徑約100光年。