宇宙中的天体,生与死总是相依相伴。比如,中小质量恒星的死,伴随着白矮星和行星状星云的生;大质量恒星的死,伴随着中子星、黑洞和超新星遗迹的生。超新星遗迹,是大质量恒星死亡前发生灾难性的爆炸后,原来恒星包层中的物质被抛射到星际空间而 The celestial bodies in the universe, life and death are always dependent on each other. For example, the death of small and medium-sized stars, accompanied by white dwarf and planetary nebulae; the death of massive stars, with the birth of neutron stars, black holes and supernova relics. Remains of supernovae, the devastating explosion that preceded the death of a massive star, have caused matter in the stellar envelope to be ejected into interstellar space