apparent semi-diameter

简明释义

视半径

英英释义

例句

1.To calculate the distance to a star, astronomers often take into account its apparent semi-diameter.

为了计算到一颗星星的距离，天文学家常常考虑它的视半径。

2.The astronomer measured the apparent semi-diameter of the moon to determine its size in the night sky.

天文学家测量了月球的视半径以确定其在夜空中的大小。

3.The apparent semi-diameter of Saturn's rings can be affected by the angle of observation.

观察角度会影响土星环的视半径。

4.The apparent semi-diameter of the sun varies slightly due to atmospheric conditions.

由于大气条件，太阳的视半径略有变化。

5.Using a telescope, we can observe the apparent semi-diameter of Jupiter's Great Red Spot.

通过望远镜，我们可以观察到木星大红斑的视半径。

作文

In the field of astronomy, understanding various measurements and terms is crucial for comprehending the vastness of our universe. One such term that often comes up in discussions about celestial bodies is the apparent semi-diameter. The apparent semi-diameter refers to the angle that a celestial body subtends at the observer's eye, essentially describing how large it appears from a given distance. This measurement is particularly significant when observing planets, moons, and stars, as it helps astronomers and enthusiasts alike gauge their size and distance from Earth.The concept of apparent semi-diameter can be better understood by considering how we perceive objects in our daily lives. For instance, when we look at the moon on a clear night, it seems larger when it is near the horizon compared to when it is high in the sky. This phenomenon is not due to a change in the moon's actual size but rather due to the way our brains interpret distance and size. Similarly, the apparent semi-diameter of celestial bodies changes based on their distance from Earth and the observer's location.Astronomers use the apparent semi-diameter to make important calculations regarding the distances between celestial objects and their sizes. For example, when observing a planet like Jupiter, its apparent semi-diameter can provide insights into its actual diameter and distance from Earth. By knowing the distance to Jupiter and measuring its apparent semi-diameter, astronomers can apply trigonometric principles to calculate its true size. This information is vital for understanding not just Jupiter, but also other planets and moons in our solar system.Moreover, the apparent semi-diameter plays a role in determining the brightness of celestial objects. The larger the apparent semi-diameter, the more light it reflects towards Earth, making it appear brighter. This principle is essential for astronomers when they are cataloging stars and other celestial entities. By measuring the apparent semi-diameter, they can classify objects based on their luminosity and distance, contributing to our overall understanding of the universe.In astrophysics, the apparent semi-diameter is also important in studying phenomena such as eclipses and transits. During a solar eclipse, for instance, the apparent semi-diameter of the moon must be precisely calculated to predict when it will obscure the sun. Understanding this measurement allows scientists to make accurate predictions about the timing and visibility of such events, which can be crucial for both scientific observation and public interest.In conclusion, the term apparent semi-diameter may seem technical, but it encapsulates a fundamental aspect of astronomical observation. By grasping its meaning and significance, we can enhance our appreciation for the beauty and complexity of the cosmos. Whether we are gazing at the moon or studying distant galaxies, the apparent semi-diameter provides us with a window into understanding the scale and dynamics of the universe around us.

在天文学领域，理解各种测量和术语对于理解我们宇宙的广阔性至关重要。其中一个在讨论天体时经常出现的术语是表观半径。表观半径指的是一个天体在观察者眼中所形成的角度，基本上描述了它从给定距离看起来有多大。当观察行星、月球和恒星时，这一测量尤其重要，因为它帮助天文学家和爱好者评估它们的大小和与地球的距离。通过考虑我们日常生活中如何感知物体，可以更好地理解表观半径的概念。例如，当我们在晴朗的夜晚观察月亮时，当它靠近地平线时，它似乎比当它高挂在空中时要大。这种现象并不是由于月亮的实际大小变化，而是由于我们的大脑对距离和大小的解读方式相同。因此，天体的表观半径会根据它们与地球的距离和观察者的位置而变化。天文学家利用表观半径进行关于天体之间距离和大小的重要计算。例如，在观察木星时，其表观半径可以提供有关其实际直径和与地球距离的见解。通过知道木星的距离并测量其表观半径，天文学家可以应用三角学原理来计算其真实大小。这些信息对于理解木星以及我们太阳系中的其他行星和卫星至关重要。此外，表观半径在确定天体亮度方面也起着重要作用。表观半径越大，反射到地球的光线就越多，使其看起来更亮。这一原理对于天文学家在编目恒星和其他天体时至关重要。通过测量表观半径，他们可以根据亮度和距离对物体进行分类，从而为我们对宇宙的整体理解做出贡献。在天体物理学中，表观半径在研究日食和过境等现象时也很重要。例如，在日食期间，必须精确计算月球的表观半径以预测何时会遮挡太阳。理解这一测量使科学家能够准确预测这些事件的时间和可见性，这对于科学观察和公众兴趣都是至关重要的。总之，术语表观半径可能看起来技术性，但它包含了天文观测的一个基本方面。通过掌握它的含义和重要性，我们可以增强对宇宙之美和复杂性的欣赏。无论我们是在凝视月亮还是研究遥远的星系，表观半径都为我们提供了一个了解周围宇宙规模和动态的窗口。