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

该项目的目标是更好地了解大质量恒星的最终寿命。在生命的末期，所有质量大约是太阳十倍以上的恒星都会形成一个铁核，一旦其质量超过临界极限，铁核就会从地球大小坍塌到城市大小。在许多情况下，这会导致无光的超新星爆炸，但越来越多的证据表明，这并不是唯一的结果。这项工作将：(A)发现或限制产生黑洞而不发生超新星爆炸的大质量恒星的比例；(B)澄清最不发光的超新星爆炸和不导致超新星爆炸的大质量恒星的可变性之间的界限；(C)在恒星灭亡前测量它们的性质，包括对它们的可变性进行开创性的研究。该项目将促进我们对这些大质量恒星的科学理解，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TWIN8.4M大型双筒望远镜监测附近27个恒星形成星系中的所有大质量演化恒星。主要目标是：(1)发现或对核心坍塌失效的比例设定有趣的限制限制，从而在没有超新星爆炸的情况下产生黑洞；(2)测量SN前体的性质，同时开创性地研究它们的可变性和双星性；(3)探索最微弱的SN和恒星爆发之间的边界，特别是通过更好地理解SN“冒名顶替者”的性质和SN2008S类尘埃瞬变。在这样做的同时，该项目将促进学生和博士后的培训，并扩大公众对科学的理解和兴趣，这得益于他们对恒星及其复杂的死亡途径的痴迷。

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.