hour circle

简明释义

时圈时圈

英英释义

例句

1.Navigators rely on the hour circle to determine their position at sea.

航海者依赖于时圈来确定他们在海上的位置。

2.The telescope was equipped with a rotating hour circle to track celestial objects accurately.

这台望远镜配备了一个旋转的时圈，以准确跟踪天体。

3.In astronomy, the hour circle is crucial for mapping the celestial sphere.

在天文学中，时圈对于绘制天球至关重要。

4.The astronomer used the hour circle to measure the position of stars in the night sky.

天文学家使用时圈来测量夜空中星星的位置。

5.To find the local sidereal time, you need to adjust the hour circle based on your longitude.

要找到当地的恒星时间，您需要根据您的经度调整时圈。

作文

In the realm of astronomy, the concept of an hour circle is fundamental to understanding celestial navigation and the movement of stars across the night sky. An hour circle can be defined as a great circle on the celestial sphere that passes through both the celestial poles and a given celestial object. This means that every star in the sky can be associated with its own hour circle, which helps astronomers determine its position relative to the Earth. The significance of the hour circle lies in its role in measuring time and the rotation of the Earth. As the Earth rotates on its axis, different hour circles come into view, allowing observers to track the passage of time based on the position of celestial bodies. For example, when the Sun crosses a particular hour circle, it marks noon for observers located along that circle. This relationship between the hour circle and timekeeping is crucial for navigation, as sailors and explorers relied on the stars to guide their journeys long before the advent of modern technology.Understanding the hour circle also involves grasping the concept of right ascension and declination, which are the celestial equivalents of longitude and latitude. Right ascension is measured along the hour circle, while declination measures how far north or south an object is from the celestial equator. By knowing the right ascension of a star and its corresponding hour circle, astronomers can pinpoint its location in the sky at any given time.Moreover, the hour circle serves as a tool for amateur astronomers who wish to locate specific stars or constellations. By using star charts and understanding the relationship between the hour circle and local time, enthusiasts can enhance their stargazing experience. For instance, if a star has a right ascension of 5 hours, it will be found along its hour circle when the local time is approximately 5 PM, assuming the observer is in the correct time zone.In conclusion, the hour circle is a vital concept in astronomy that facilitates our understanding of celestial navigation, timekeeping, and the positioning of stars. Its implications extend beyond theoretical knowledge; they are practical tools that have guided humanity for centuries. Whether for professional astronomers or casual stargazers, a firm grasp of the hour circle enriches our appreciation of the universe and our place within it. By studying the hour circle, we not only learn about the cosmos but also connect with the ancient navigators who once looked to the stars for guidance on their journeys across the seas.

在天文学领域，hour circle的概念对于理解天体导航和星星在夜空中的运动至关重要。hour circle可以定义为一个通过天球的两个极点和给定天体的伟大圆圈。这意味着夜空中的每一颗星星都可以与其自己的hour circle相关联，这帮助天文学家确定其相对于地球的位置。hour circle的重要性在于它在测量时间和地球自转中的作用。随着地球绕其轴旋转，不同的hour circles进入视野，使观察者能够根据天体的位置跟踪时间的推移。例如，当太阳穿过某个特定的hour circle时，它标志着位于该圆圈上的观察者的正午。这种hour circle与计时之间的关系对导航至关重要，因为水手和探险者在现代技术出现之前就依赖星星来指导他们的旅程。理解hour circle还涉及掌握赤经和赤纬的概念，这些概念是经度和纬度的天文等价物。赤经沿着hour circle测量，而赤纬则测量物体距离天球赤道的南北位置。通过知道一颗星星的赤经及其对应的hour circle，天文学家可以在任何给定时间准确定位其在天空中的位置。此外，hour circle还作为业余天文学家寻找特定星星或星座的工具。通过使用星图并理解hour circle与当地时间之间的关系，爱好者可以增强他们的观星体验。例如，如果一颗星星的赤经是5小时，那么当当地时间大约是下午5点时，它将出现在其hour circle上，前提是观察者处于正确的时区。总之，hour circle是天文学中一个重要的概念，它促进了我们对天体导航、计时和星星定位的理解。它的影响超越了理论知识；它们是几世纪以来引导人类的实用工具。无论是专业天文学家还是休闲观星者，对hour circle的牢固掌握都能丰富我们对宇宙及其在其中位置的欣赏。通过研究hour circle，我们不仅学习关于宇宙的知识，还与那些曾经仰望星空以指导他们横渡海洋的古代航海者建立联系。