作者: Science Alert | 2020年07月01日 14:20 | 0 人覺得有用
Nothing rages against the dying of the light harder than a star. Their death throes are wild and violent as the star is wracked with colossal quakes, throwing vast amounts of stellar material out into the surrounding space.
Studying the gas and dust thrown off in such events can help us understand how these stars die… and now Hubble has studied in greater detail than ever before two of the dustiest, gassiest star deaths in the galaxy.
They're two planetary nebulae (so named because initially, these objects were first described as planet-like in the 18th century) called NGC 6303, or the Butterfly Nebula, and NGC 7027. And Hubble has used the full wavelength range of its Wide Field 3 camera - from near ultraviolet to near-infrared - to study the turbulent processes within them.
這兩個行星狀星云（取這個名字是因為最初在18世紀時說這些物體外觀類似行星）名為NGC 6303，也叫蝴蝶星云，和NGC 7027。哈勃利用第三代廣域照相機的全波長范圍，即從近紫外到近紅外的范圍，研究星云內部的湍流過程。
"When I looked in the Hubble archive and realised no one had observed these nebulae with Hubble's Wide Field Camera 3 across its full wavelength range, I was floored," said astronomer Joel Kastner of Rochester Institute of Technology in New York.
"These new multi-wavelength Hubble observations provide the most comprehensive view to date of both of these spectacular nebulae. As I was downloading the resulting images, I felt like a kid in a candy store."
Both nebulae are probably descended from progenitor stars around three to five times the mass of the Sun; these progenitors collapsed into white dwarfs when they died. (Stars more massive than eight solar masses become neutron stars; and stars greater than 30 solar masses become black holes.) And both have high ionisation and excitation, indicating the stars inside them are very hot.