Massive stars as cosmic engines

作为宇宙引擎的大质量恒星大质量恒星包括最初质量超过8个太阳质量的所有恒星，这些恒星在核燃烧生命结束时作为超新星坍缩，留下中子星或黑洞。由于一颗普通星星的光输出是其质量的立方，因此一颗100太阳质量的星星就可以相当于一百万个太阳发出的光。超过20个太阳质量，大质量恒星进一步区分自己的强风，范围高达太阳的十亿倍。 因此，虽然稀有且寿命短暂，但大质量恒星会向星际介质提供大量辐射，主要是致命的紫外线和浓缩物质，准备建造更多像地球一样的恒星和行星。 这在早期宇宙中尤其重要，当时形成的第一批恒星可能都非常巨大。该计划的主要目标是探索：（1）如果辐射压力本身就可以驱动超新星前的极端风，即He-burning WR阶段，使用微型卫星MOST上的第一台加拿大空间望远镜，（2）建造一颗纳米卫星，系统地探测大量明亮的大质量恒星的低振幅不稳定性，（3）风在发光中膨胀的确切方式，热恒星，（4）磁场在加速风中的作用，（5）尘埃颗粒如何形成并在热的发光恒星的恶劣环境中生存的难题，（6）最大质量恒星的上限（是100，150还是200太阳质量？），(7)我们整个银河系中WR星的含量，大部分隐藏在星际尘埃中，以及（8）WR星是否真的爆炸为超新星，在某些情况下导致宇宙中最具能量（尽管短暂）的现象，长伽马射线爆发。

MASSIVE STARS AS COSMIC ENGINES Massive stars comprise all stars initially above 8 solar masses, that collapse as supernovae at the end of their nuclear-burning lives, leaving behind neutron stars or black holes. Since the light output of a normal star goes as the cube of its mass, a single, 100 solar-mass star can match the total light from a million Suns. Above 20 solar masses, massive stars further distinguish themselves by their strong winds, ranging up to a billion times that of the Sun.  Thus, although rare and short-lived, massive stars deliver huge quantities of radiation, mostly as lethal ultraviolet, and enriched material to the interstellar medium, ready to build more stars and planets like Earth.  This was especially important in the early Universe, when the first stars formed were probably all very massive. The main goals of this program are to explore: (1) if radiation pressure alone can drive the extreme winds of the pre-supernova, He-burning WR phase, using the first Canadian space telescope on board the microsatellite MOST, (2) building a nanosatellite to systematically probe the low-amplitude instability properties of a large number of bright, massive stars, (3) the exact way in which the winds expand in luminous, hot stars, (4) the role of magnetic fields in accelerating the winds, (5) the puzzle of how dust grains form and survive in the hostile environments of hot, luminous stars, (6) the upper mass cut-off for the most massive stars (is it 100, 150, or 200 solar masses?), (7) the content of WR stars in our whole Galaxy, mostly hidden by interstellar dust, and (8) whether WR stars actually explode as supernovae, leading in some cases to the most energetic (although short-lived) phenomenon in the Universe, the long gamma-ray bursts.