Armagh Observatory Consolidated Grant 2015 - 2018

这项研究结合了对我们的太阳、太阳系和恒星（包括单系统和双星系统的演化）的研究，以及恒星作为示踪剂对我们了解更广泛的宇宙所起的作用。几年前人们还认为褐矮星不可能发射出大量的无线电波，而现在人们发现褐矮星能发射出极其明亮的无线电波。对这些明显的主序“侏儒”的研究可能为解决传统日冕天体物理学中长期存在的难题提供重要线索。在我们对恒星的认识中，一个关键的不确定性是双星的作用以及一颗恒星在演化过程中与另一颗恒星的相互作用。在这种情况下，在不同的时间，来自一颗恒星的物质可以流向另一颗恒星（有时反之亦然），更罕见的是，两颗恒星可能会碰撞产生一个更大的物体，有时也会发生巨大的爆炸，称为超新星。这样的恒星碰撞被称为合并，它们会产生具有不同寻常化学成分的物体，这些物体含有两颗恒星联合历史的“化石”记录，或者（在超新星的情况下）产生具有短暂属性的物体，可以用来探测宇宙中最遥远的部分。我们研究的第二个方面涉及恒星磁场的测量以及磁场对恒星演化的影响。为什么有些恒星具有磁性，而另一些则不具有磁性，这仍然是一个谜，我们的工作旨在提供可靠的数据，以比较不同的观点。第三个是宇宙中质量最大的恒星的起源、演化和命运。它们的演化是由强大的恒星风主导的。这些恒星是在生命结束时发生破坏性爆炸，还是最终坍缩产生黑洞？在这两种情况下，恒星风对邻近恒星和附近恒星形成区域的影响是什么？这项工作将极大地促进我们对恒星的理解。我们对太阳——离我们最近的恒星——的研究不仅对理解恒星有意义，而且对我们太阳可见大气的过程如何产生观测到的现象也有意义，这些现象最终导致了百万度的日冕的加热和太阳风的形成。太阳是一颗变星，在太阳黑子极大期和极小期之间表现出大约11年的主导磁活动周期。目前，一组宇宙飞船对太阳进行了持续的观测，我们通过这些航天器上的仪器（覆盖了很宽的波长范围）进行详细的观测，旨在提高我们对太阳大气物理学的理解，以及太阳大气偶尔产生大规模质量和能量爆发的机制。其中一些爆发具有巨大的能量，不仅会导致地球高层大气中可见的极光，还会对地球上的航天器和大型电力系统产生潜在的破坏性影响。太阳多变的磁活动对地球在近空间环境中的位置有着广泛的影响。最后，我们试图了解我们的行星系统的起源，以及其中的小天体——彗星和小行星（及其碎片）的演变。我们将研究主要行星轨道上的特洛伊小行星，例如木星和火星的轨道，以检验太阳系起源的理论，并更好地了解小天体如何随着时间的推移而演变。我们还将研究彗星衰变为流星体流的详细过程，流星体流的碎片偶尔会穿过地球轨道，产生众所周知的流星雨现象——在地球大气层中燃烧小块彗星物质。研究太阳系中这些天体及其相互关系不仅有有趣的科学理由，而且对地球近空间的研究也有重要的实际好处。

This research combines studies of our Sun, Solar System, and Stars (including the evolution of single and binary systems), and the role played by stars as tracers for our understanding of the wider Universe. Brown dwarfs, thought just a few years ago to be incapable of emitting any significant amounts of radio waves, have been discovered putting out extremely bright beams of radio emission. The study of these apparent 'runts' of the main sequence menagerie could hold vital clues to solving long standing conundrums in conventional coronal astrophysics.A key uncertainty in our knowledge of stars is the role of binarity and the interactions of one star with another during their evolution. In this case, at different times, material from one star can flow onto the other (and sometimes vice versa), and more rarely two stars may collide to produce a single more massive object or sometimes a gigantic explosion called a supernova. Such stellar collisions are called mergers, and they lead to objects with unusual chemical composition which contain a 'fossil' record of the two stars' joint history or (in the case of a supernova) to an object with short-lived properties that can be used to probe the most distant parts of the Universe. A second aspect of our research concerns the measurement of stellar magnetic fields and the impact of magnetic fields on a star's evolution. The reason why some stars are magnetic, and others less so, remains a mystery, and our work aims to provide reliable data with which to compare the different ideas. A third is the origin, evolution and fate of the most massive stars in the Universe. Their evolution is dominated by powerful stellar winds. Do such stars explode disruptively at the end of their lives, or do they ultimately collapse to produce black holes; and, in either case, what is the effect of the stellar wind on neighbouring stars and the nearby star-forming regions? This work will significantly advance our understanding of stars.Our work on the Sun - our nearest Star - has implications not just for understanding stars generally but also for how processes in our Sun's visible atmosphere produce the observed phenomena that ultimately leads to heating of its million-degree Corona and the formation of the Solar Wind. The Sun is a variable star showing a dominant roughly 11-year cycle of magnetic activity between episodes of sunspot maximum and minimum. It is currently observed continuously by a fleet of spacecraft, and our detailed observations from instruments onboard these spacecraft (which cover a very wide range of wavelengths) are designed to improve our understanding of the physics of the Sun's atmosphere and the mechanisms by which it produces occasional massive outbursts of mass and energy. Some of these outbursts have huge power, and can lead not just to the visible appearance of aurorae in the Earth's upper atmosphere but to potentially damaging effects on spacecraft and large-scale power systems on Earth. The variable magnetic activity of the Sun has broad implications for Earth's place in the near-space environment.Lastly, we seek to understand the origin of our planetary system, and the evolution of the small bodies - comets and asteroids (and their debris) - within it. We will study the Trojan asteroids in the orbits of the major planets, for example those of Jupiter and Mars, to test theories of the origin of the Solar System and to understand better how small bodies evolve with time. We will also investigate the detailed processes by which comets decay into meteoroid streams, debris from which may occasionally cross Earth's orbit to produce the well-known phenomenon of a meteor shower - the burning up of small pieces of cometary material in the Earth's atmosphere. Not only are there interesting scientific reasons to study such objects and their interrelationships with each other in the Solar System, but the study of Earth's near-space has important practical benefits.