absolute magnitude

简明释义

绝对星等

英英释义

例句

1.The astronomer calculated the absolute magnitude of the star to determine its true brightness from a standard distance.

天文学家计算了星星的绝对星等以确定其从标准距离的真实亮度。

2.Understanding the absolute magnitude helps in estimating the distances of celestial objects.

理解绝对星等有助于估算天体的距离。

3.The absolute magnitude of the sun is approximately +4.83.

太阳的绝对星等大约为+4.83。

4.The absolute magnitude of a supernova is often much brighter than that of regular stars.

超新星的绝对星等通常比普通星星要亮得多。

5.By comparing the absolute magnitude of different stars, we can classify them into various categories.

通过比较不同星星的绝对星等，我们可以将它们分类为不同类别。

作文

In the field of astronomy, understanding the properties of stars is essential for grasping the vastness of our universe. One crucial concept that astronomers use to describe the brightness of stars is absolute magnitude. The term absolute magnitude refers to the intrinsic brightness of a celestial object, particularly stars, measured as if it were placed at a standard distance of 10 parsecs (approximately 32.6 light-years) from Earth. This standardized measurement allows astronomers to compare the true brightness of different stars without the interference of distance. The significance of absolute magnitude lies in its ability to provide a clearer understanding of how luminous a star truly is, independent of its distance from Earth. For instance, two stars may appear equally bright in the night sky, but one might be much closer than the other. By calculating their absolute magnitude, astronomers can determine which star is genuinely more luminous. This is vital for studying stellar evolution and the life cycles of stars.To illustrate this concept, consider two hypothetical stars: Star A and Star B. Star A has an apparent magnitude (the brightness as seen from Earth) of 1, while Star B has an apparent magnitude of 3. If we find out that Star A is located at a distance of 5 parsecs and Star B is at 20 parsecs, we would need to calculate their absolute magnitudes to understand their true luminosity. After calculations, we discover that Star A has an absolute magnitude of -2, while Star B has an absolute magnitude of +1. This information reveals that Star A is significantly brighter than Star B, despite their apparent brightness being misleading due to their distances.Furthermore, the absolute magnitude scale is logarithmic, meaning that a difference of 5 in absolute magnitude corresponds to a brightness factor of 100. Thus, a star with an absolute magnitude of 0 is 100 times brighter than a star with an absolute magnitude of 5. This scaling allows astronomers to categorize stars into different classes based on their luminosity, which aids in identifying and classifying various types of stars, such as giants, supergiants, and dwarfs.In addition to its importance in stellar classification, absolute magnitude also plays a significant role in understanding the structure of galaxies and the universe itself. By studying the absolute magnitudes of stars within a galaxy, astronomers can infer the distance to that galaxy using a method known as the distance modulus. This relationship between distance, apparent magnitude, and absolute magnitude is fundamental in mapping the cosmos and understanding its expansion.In conclusion, the concept of absolute magnitude is pivotal in the field of astronomy. It allows scientists to assess the true brightness of stars and celestial objects, facilitating comparisons that are essential for understanding the universe's structure and evolution. As we continue to explore the cosmos, the knowledge of absolute magnitude will undoubtedly remain a cornerstone in our quest to comprehend the vast and intricate tapestry of the universe.

在天文学领域，理解恒星的特性对于掌握我们宇宙的浩瀚至关重要。天文学家用来描述恒星亮度的一个关键概念是绝对星等。术语绝对星等指的是天体的内在亮度，特别是恒星，测量时假设它位于距离地球10秒差距（大约32.6光年）的标准距离。这一标准化的测量方法使天文学家能够比较不同恒星的真实亮度，而不受距离的干扰。绝对星等的重要性在于它能够提供更清晰的理解，即恒星的真实亮度与其距离无关。例如，两颗恒星在夜空中看起来同样明亮，但其中一颗可能离我们更近。通过计算它们的绝对星等，天文学家可以确定哪颗恒星确实更亮。这对于研究恒星演化和恒星的生命周期至关重要。为了说明这个概念，考虑两颗假设的恒星：恒星A和恒星B。恒星A的视星等（从地球上看到的亮度）为1，而恒星B的视星等为3。如果我们发现恒星A位于5秒差距，而恒星B位于20秒差距，我们需要计算它们的绝对星等以了解它们的真实亮度。经过计算，我们发现恒星A的绝对星等为-2，而恒星B的绝对星等为+1。这些信息表明，尽管它们的视亮度可能会误导我们，但实际上恒星A的亮度远高于恒星B。此外，绝对星等的尺度是对数的，这意味着绝对星等相差5个单位对应亮度的100倍变化。因此，绝对星等为0的恒星比绝对星等为5的恒星亮100倍。这种缩放使天文学家能够根据亮度将恒星分类，这有助于识别和分类各种类型的恒星，如巨星、超巨星和矮星。除了在恒星分类中的重要性，绝对星等还在理解星系和宇宙本身的结构中发挥着重要作用。通过研究星系中恒星的绝对星等，天文学家可以使用称为距离模数的方法推断出该星系的距离。这种距离、视星等和绝对星等之间的关系在绘制宇宙图和理解宇宙扩展方面是基础性的。总之，绝对星等的概念在天文学领域至关重要。它使科学家能够评估恒星和天体的真实亮度，促进了进行必要比较的能力，这对于理解宇宙的结构和演变至关重要。随着我们继续探索宇宙，绝对星等的知识无疑将继续成为我们理解宇宙浩瀚而复杂的织锦的基石。