A Search for Failed Supernovae and Other Observational Constraints on the Supernova Mechanism

这个项目的目标是更好地了解大质量恒星的最终命运。所有质量大约是太阳十倍以上的恒星在生命的尽头都会形成一个铁核，一旦质量超过临界极限，这个铁核就会从地球大小坍缩到一座城市大小。在许多情况下，这导致了一个发光的超新星爆炸，但越来越多的证据表明，这不是唯一的结果。这项工作将(a)对产生黑洞而不发生超新星爆炸的大质量恒星的比例设定有用的限制；(b)澄清最不发光的超新星爆炸与不导致超新星爆炸的大质量恒星的变异性之间的界限；(c)在这些恒星死亡之前测量它们的特性，包括对它们的变异性进行开创性的研究。该项目将促进我们对这些巨大恒星的科学理解，同时培养下一代科学家。为了更好地了解大质量恒星的命运，研究步骤包括使用独特的、多方面的观测和理论方法。该项目的核心是使用一对8.4米的大型双筒望远镜来监测附近27个恒星形成星系中所有的大质量演化恒星。主要目标是：(1)发现或设置有趣的限制，限制核心坍塌失败的比例，产生一个没有超新星爆炸的黑洞；(2)测量SN祖细胞的性质，率先研究其变异性和二值性；(3)探索最微弱的SN和恒星爆发之间的界限，特别是通过更好地了解SN“冒名者”和SN2008S类尘埃瞬变的性质。与此同时，该项目将促进学生和博士后的培训，扩大公众对科学的理解和兴趣，帮助他们对恒星及其复杂的死亡之路着迷。

The goal of this project is to better understand the final fatesof massive stars. At the end of their lives, all stars more thanroughly ten times the mass of our Sun build an iron core whichcollapses from the size of the Earth to the size of a city onceits mass exceeds a critical limit. In many cases this results in anluminous, supernova explosion, but there is increasing evidencethat this is not the only outcome. This work will (a) discoveror set useful constraints on the fraction of massive stars thatproduce a black hole without a supernova explosion; (b) clarifythe boundary between the least luminous supernova explosions and thevariability of massive stars that does not lead a supernova explosion; and (c)measure the properties of these stars just before their deaths,including pioneering studies of their variability. The projectwill advance our scientific understanding of these massive starswhile training the next generation of scientists.The research steps for a better understanding of the fates ofmassive stars include using unique, multifaceted observational andtheoretical approaches. The centerpiece is a project using thetwin 8.4m Large Binocular Telescope to monitor all the massiveevolved stars in 27 nearby star-forming galaxies. The primarygoals are to:(1) Discover or set interesting constraining limits on the fraction of core collapses that fail, producing a black hole without a supernova explosion;(2) Measure the properties of SN progenitors while pioneering studies of their variability and binarity;(3) Explore the boundary between the faintest SN and stellar outbursts, in particular by better understanding the nature of the SN "impostors" and the SN2008S class of dusty transients.While doing so, the project will advance the training of students andpost-docs and broaden the public's understanding and interest in science,aided by their fascination with stars and their complicated roads todeath.