local sidereal noon

简明释义

地方恒星午

英英释义

例句

1.Astronomers often use the term local sidereal noon to determine when the stars will be at their highest point in the sky.

天文学家常用术语地方恒星中午来确定星星在天空中最高点的时间。

2.We scheduled the telescope observation for right after local sidereal noon to avoid interference from the Sun.

我们将望远镜观察安排在地方恒星中午之后，以避免阳光干扰。

3.The local sidereal noon occurs approximately every 23 hours and 56 minutes.

每约23小时56分钟会发生一次地方恒星中午。

4.During local sidereal noon, the Sun is aligned with the local meridian, which is crucial for navigation.

在地方恒星中午时，太阳与当地子午线对齐，这对导航至关重要。

5.To calculate the position of celestial objects, you need to know the local sidereal noon for your location.

要计算天体的位置，您需要知道您所在位置的地方恒星中午。

作文

Understanding the concept of local sidereal noon is essential for astronomers and anyone interested in celestial navigation. While most people are familiar with the idea of noon as the time when the sun is highest in the sky, local sidereal noon refers to a different kind of noon that is based on the position of distant stars rather than our Sun. To grasp this concept better, we first need to explore what 'sidereal' means. The term 'sidereal' comes from the Latin word 'sidus,' meaning star. Therefore, sidereal time is a measure of time based on the Earth's rotation relative to the fixed stars, rather than the Sun. This is particularly important for astronomers who need precise timing to observe celestial events.The Earth rotates on its axis approximately every 24 hours, but it also moves along its orbit around the Sun. Because of this orbital motion, a solar day—the time it takes for the Sun to return to the same position in the sky—is slightly longer than a sidereal day. A sidereal day lasts about 23 hours, 56 minutes, and 4 seconds. Thus, local sidereal noon occurs when a particular star crosses the local meridian, which is an imaginary line that runs from north to south through the observer's location.For practical applications, local sidereal noon is crucial for astronomers using telescopes. When they want to align their instruments to observe a specific star, knowing when that star will be at its highest point in the sky helps them achieve accurate observations. This timing can significantly affect the quality of the data collected, especially in astrophotography and spectroscopy.Moreover, local sidereal noon varies depending on your geographical location. For example, if you are located in New York City, local sidereal noon will occur at a different time compared to someone in Los Angeles, even though both locations are in the same time zone. This variation is due to the Earth's curvature and the observer's position on the planet. Therefore, astronomers must account for their specific location when calculating local sidereal noon.In summary, understanding local sidereal noon offers valuable insights into the relationship between time, the Earth, and the universe. It highlights the intricacies of celestial mechanics and serves as a reminder of how our perception of time can differ based on various factors. For those engaged in astronomy or navigation, mastering this concept is not just an academic exercise; it is a practical necessity that enhances our ability to explore the cosmos. As we continue to learn more about our universe, concepts like local sidereal noon will remain fundamental to our understanding of the stars and their movements in relation to our own planet.

理解地方恒星中午的概念对于天文学家和任何对天体导航感兴趣的人来说都是至关重要的。虽然大多数人都熟悉中午这个概念，即太阳在天空中最高的位置，但地方恒星中午则是基于遥远恒星的位置，而不是我们的太阳。要更好地掌握这个概念，我们首先需要探索“恒星”这个词的含义。“恒星”一词源于拉丁文“sidus”，意为星星。因此，恒星时间是基于地球相对于固定星星的自转而测量的时间，而不是太阳。这对于需要精确时机以观察天文事件的天文学家尤为重要。地球大约每24小时绕其轴自转一次，但它也沿着绕太阳的轨道运动。由于这种轨道运动，太阳日——即太阳返回天空中同一位置所需的时间——比恒星日稍长。一个恒星日大约持续23小时56分钟4秒。因此，地方恒星中午发生在特定星星穿过当地子午线时，子午线是从北到南穿过观察者位置的假想线。在实际应用中，地方恒星中午对使用望远镜的天文学家至关重要。当他们想要调整仪器以观察特定星星时，知道那颗星星将在天空中达到最高点的时间有助于他们实现精确的观察。这种时机显著影响收集数据的质量，特别是在天体摄影和光谱学中。此外，地方恒星中午根据你的地理位置而有所不同。例如，如果你位于纽约市，地方恒星中午的时间将与洛杉矶的某个人不同，即使这两个地方在同一个时区。这种变化是由于地球的曲率和观察者在地球上的位置。因此，天文学家在计算地方恒星中午时必须考虑他们的具体位置。总之，了解地方恒星中午为我们提供了关于时间、地球和宇宙之间关系的宝贵见解。它突显了天体力学的复杂性，并提醒我们时间的感知如何因各种因素而异。对于那些从事天文学或导航的人来说，掌握这一概念不仅仅是学术练习；它是一种实用的必要性，增强了我们探索宇宙的能力。随着我们继续学习更多关于宇宙的知识，像地方恒星中午这样的概念将始终是我们理解星星及其相对于我们自己星球运动的基础。