Periodic Phenomena and the Evolution of Cataclysmic Variable Binary Stars

1. 大多数恒星出现在包含两个或更多物体的系统中。有些双星包括一颗密度很大的恒星，叫做？白矮星?？ 把太阳质量的恒星塞进地球大小的体积里？加上一颗比太阳更小、更红的普通恒星。在某些情况下，红星可以将质量流转移到白矮星周围的气体盘中。物质通过圆盘螺旋进入，聚集在白矮星上，迅速升温，并在一段时间内发出明亮的光芒。由此产生的能量爆发给了这些所谓的？灾难性的变量?（简历）他们的名字。监测cv的爆发，或者研究它们所显示的丰富的周期信号，需要更多的望远镜时间，这是专业天文学家无法负担得起的。在过去的二十年里，首席研究员一直领导着一个由世界各地的业余天文学家组成的小组，使用小型望远镜进行观测。他称之为？后院天体物理中心？？ 以获得必要的观察。事实证明，这些数据对研究这些系统的专业天文学家非常有用。这个项目继续了卓有成效的合作，让世界各地的业余爱好者参与到有价值的？公民科学。2。关于CVs的大部分信息来自于它们表现出的各种周期信号。然而，很少有专业的观察者愿意投入必要的时间来监测这些系统，以测量周期变化（这可以揭示它们的进化时间尺度）或获取它们可能显示的其他周期性现象的数据。这些包括轨道周期和周期变化，旋转周期，以及所谓的“超级峰”。在某些类型的简历中这项提议寻求从业余天文学家使用小型望远镜的全球网络中获得长期的时间序列光度。叫？后院天体物理中心？还是CBA ？为了满足这种需要。此外，首席研究员希望能够利用获得的数据来帮助区分CV系统命运的两种截然相反的理论：供体恒星是由于质量转移到白矮星主恒星而逐渐消失，还是由于白矮星上的新星爆炸而蒸发？光度时间序列数据及其对提高我们对cv的理解的意义构成了本项目的智力价值。该项目的更广泛影响源于首席研究员？继续激励和吸引全球业余天文学家社区收集这些系统的科学有用的光度数据的能力。业余观测者心甘情愿地不断填补被专业观测者抛弃的观测数据的空白，在首席研究员的领导下，他们在各种各样的cv上产生了源源不断的有价值的光度数据。

1. Most stars occur in systems containing two or more objects. Some pairs include a very dense star called a ?white dwarf? ? a star with the mass of our Sun crammed into a volume about the size of the Earth ? plus an ordinary star smaller and redder than the Sun. In some cases, the red star can transfer a stream of mass onto a disk of gas around the white dwarf. Matter spirals in through the disk to accumulate on the white dwarf, heating up rapidly and shining brightly for a time. The resulting outburst of energy gives these so-called ?cataclysmic variables? (CVs) their name. Monitoring CVs for outbursts, or to study the wealth of periodic signals they display, requires far more telescope time than professional astronomers can afford. For the past two decades, the Principal Investigator has been leading a world-wide group of amateur astronomers using small telescopes ? which he calls the ?Center for Backyard Astrophysics? ? to obtain the necessary observations of CVs. The data have proven extremely useful to professional astronomers who study these systems. This project continues that fruitful collaboration, engaging amateurs around the world in valuable ?citizen science.?2. Most of the information about CVs comes from various periodic signals they exhibit. Yet few professional observers have been willing to devote the time necessary to monitor these systems in order to measure period changes (which can reveal their evolutionary timescales) or to obtain data on additional periodic phenomena they may display. These include orbital periods and period changes, rotational periods, and so-called ?superhumps? in certain classes of CVs. This proposal seeks to obtain long-term time-series photometry from a world-wide network of amateur astronomers using small telescopes ? called the ?Center for Backyard Astrophysics? or CBA ? to fill this need. In addition, the Principal Investigator expects to be able to use the data obtained to help distinguish between two diametrically opposed theories for the fate of CV systems: Are the donor stars whittled away by mass transfer to the white dwarf primary, or are they evaporated by nova explosions on the white dwarfs? The photometric time-series data and their implications for improving our understanding of CVs constitute the Intellectual Merit of this project. The Broader Impacts of this project stem from the Principal Investigator?s continuing ability to motivate and engage the world-wide community of amateur astronomers to gather scientifically useful photometric data on these systems. The amateur observers willingly and continually fill the gap in observational data that has been largely abandoned by the professionals, and under the leadership of the Principal Investigator they produce a steady stream of valuable photometric data on a wide variety of CVs.