With its nuclear fuel exhausted, this brief, spectacular, closing phase of a sun-like star's life occurs as its outer layers are ejected and its core becomes a cooling, fading White Dwarf.

随着其核燃料的用尽，这个短暂的、壮观的、像太阳一样恒星的临近结束阶段而发生变化，因为它的外层喷发，而内核变成一个逐渐冷却、逐渐褪色的白矮星过程。

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While the planetary nebula phase is thought to last for around 10, 000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50, 000 to 90, 000 years.

虽然行星状星云阶段持续约1万年，天文学家估计其外晕的丝状物质年龄在5万至9万年间。

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It briefly introduces the source of silt at the outer waterway of Shantou Port and construction situation and regulation effect of Phase I regulation project.

简要介绍汕头港外航道泥沙来源及一期整治工程的建设情况和整治效果。

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Functional-imaging studies of the brain have revealed another tantalizing clue: During the aura phase, a wave of electrical activity sweeps over the outer, furrowed layer of the brain known as the cortex, at a pace of 2 to 3 millimeters per minute.

WSJ: Stopping a Migraine Before It Starts