Question bank: Astronomy: Galaxies

Galaxies are massive systems of stars, interstellar dust, gases, and dark matter, all held together by gravitational force. There are different types of galaxies, such as spirals, ellipticals, and irregulars, each with their distinct characteristics. Considering that the Milky Way is a spiral galaxy and that a black hole is a region of space where the gravitational force is so strong that nothing, not even light, can escape from its interior, discuss the main differences between a galaxy and a black hole, including their structures, compositions, and how they interact with the universe. Additionally, explain how astronomers use the light emitted by different celestial bodies, such as stars and nebulae, to study the composition and dynamics of galaxies, and discuss the importance of these observations for our understanding of the universe on cosmic scales.

Galaxies are vast agglomerations of stars, gas, and dust that surround us in the Universe. There are many different types of galaxies, varying in shape and size. Among the existing types of galaxies, we have elliptical, spiral, and irregular ones. Based on this information, which of the following alternatives correctly describes the relationship between galaxies, black holes, nebulae, and stars?

The universe is composed of a vast amount of galaxies, which are groupings of billions of stars, gases, and dust interconnected by the force of gravity. Galaxies can be classified into three main types: elliptical, spiral, and irregular. The Milky Way, our galaxy, is an example of a spiral galaxy. Considering this information, answer: (a) Describe the main characteristics and differences between the three types of galaxies mentioned; (b) Explain why the Milky Way is classified as a spiral galaxy; (c) Differentiate a galaxy from other celestial bodies, such as black holes, nebulae, and stars, in terms of size, composition, and structure.

Consider the following characteristics of galaxies: they are gravitationally bound systems, composed of stars, stellar remnants, gas, dust, and dark matter, all united by gravitational forces. Galaxies can be classified according to their shape as spirals, ellipticals, or irregulars. Elliptical galaxies are mainly formed by old stars and contain little or no interstellar gas and dust, while spirals have flattened disks with spiral arms, where star formation occurs. Now, relating this information to History content, imagine yourself at the end of the 18th century, when astronomy began to distinguish between galaxies, black holes, nebulae, and stars. Describe how the first astronomical observations and the subsequent classification of galaxies relate to the development of scientific knowledge about the Universe and how this distinction impacted the understanding of Earth's position in the Cosmos. In your answer, take into account the technological advances available at the time and the influence of prevailing scientific theories that shaped the scholars' worldview.

Globular clusters are the oldest known, formed over 10 billion years ago. They are made up of thousands or even millions of stars and have unique characteristics, such as a higher concentration of old stars, rich in metals, and very dense. Which of these characteristics does not apply to a globular cluster?