Chapter Review Continued Stars and Galaxies Answers Chapter 3
Chapter 15 Stars, Galaxies, and the Universe Preview Section 1 Stars Section 2 The Life Cycle of the Stars Section 3 Galaxies Section 4 Formation of the Universe Concept Map < Back Next > Preview Main
Chapter 15 Section 1 Stars Bellringer List ways that stars differ from one another. How is the sun like other stars? How is it different? Write your answers in your Science Journal. < Back Next > Preview Main
Chapter 15 Section 1 Stars What You Will Learn • Stars differ in size, temperature, composition, brightness, and color. • Distances between stars are very large and are measured in light-years. < Back Next > Preview Main
Chapter 15 Section 1 Stars Color of Stars • The color of a star indicates the star's temperature. • Red stars are the coolest, and blue stars are the hottest. • If two stars differ in color, you can conclude that they differ in temperature too. < Back Next > Preview Main
Chapter 15 Section 1 Stars Composition of Stars • Astronomers use an instrument called a spectroscope to separate a star's light into a spectrum (plural, spectra). • A spectrum is the band of colors produced when white light passes through a prism. < Back Next > Preview Main
Chapter 15 Section 1 Stars Composition of Stars, continued • A continuous spectrum shows all of the colors, while an absorption spectrum shows which wavelengths of light are absorbed. • The spectrum of a star is an absorption spectrum because the atmosphere of the star absorbs certain portions of the light produced by the star. < Back Next > Preview Main
Chapter 15 Section 1 Stars Composition of Stars, continued • The pattern of lines in a star's absorption spectrum is unique to that star. • A star's absorption spectrum can be used to determine the elements in that star's atmosphere. • Stars are made of mostly hydrogen and helium gases. < Back Next > Preview Main
Chapter 15 Stars, Galaxies, and the Universe Composition of Stars, continued < Back Next > Preview Main
Chapter 15 Section 1 Stars Classifying Stars • Stars are now classified by how hot they are. • Temperature differences between stars result in color differences that can be seen. For example, class O stars are blue—the hottest stars. < Back Next > Preview Main
Chapter 15 Section 1 Stars Classifying Stars, continued • Magnitude is used to compare the brightness of one object with the brightness of another object. • To express the brightness of stars, astronomers use a system of magnitudes. < Back Next > Preview Main
Chapter 15 Section 1 Stars Classifying Stars, continued • Positive magnitude numbers represent dim stars. Negative magnitude numbers represent bright stars. • The brightest star in the night sky, Sirius, has a magnitude of -1. 4. < Back Next > Preview Main
Chapter 15 Stars, Galaxies, and the Universe Classifying Stars < Back Next > Preview Main
Chapter 15 Section 1 Stars How Bright Is That Star? • The apparent magnitude is the brightness of a star as seen from Earth. The absolute magnitude is the brightness that a star would have at a distance of 32. 6 light-years from Earth. • If all stars were the same distance away, their absolute magnitudes would be the same as their apparent magnitudes. < Back Next > Preview Main
Chapter 15 Stars, Galaxies, and the Universe Absolute and Apparent Magnitude < Back Next > Preview Main
Chapter 15 Section 1 Stars Distance to the Stars • Because stars are so far away, astronomers use a unit called a light-year to measure the distance from Earth to the stars. • A light-year is the distance that light travels in one year, about 9. 46 trillion kilometers. < Back Next > Preview Main
Chapter 15 Section 1 Stars Motions of Stars • This apparent motion of the stars is due to Earth's rotation and its revolution around the sun. • Each star is actually moving in space. But because stars are so distant, their actual motion is hard to see. < Back Next > Preview Main
Chapter 15 Section 2 The Life Cycle of Stars Bellringer List 3 stages in the life cycle of an insect. List 3 stages in the life cycle of a human. List any stages you may know of in the life cycle of a star. Write your answers in your Science Journal. < Back Next > Preview Main
Chapter 15 Section 2 The Life Cycle of Stars What You Will Learn • During star formation, gravity pulls dust and gas into a sphere, and when the sphere gets dense enough, nuclear fusion begins. • Nuclear Fusion is an atomic reaction that fuels stars. < Back Next > Preview Main
Chapter 15 Section 2 The Life Cycle of Stars Types of Stars • Stars can be classified by mass, size, brightness, color, temperature, composition, and age. • A star is classified differently as its properties change. Its properties often relate to whether the star can generate energy by nuclear fusion. < Back Next > Preview Main
Chapter 15 Section 2 The Life Cycle of Stars The Life Cycle of Sunlike Stars • New stars form from gas and dust, which are pulled into a sphere by gravity. • As the sphere becomes denser, hydrogen combines into helium and energy is released in a process called nuclear fusion. < Back Next > Preview Main
Chapter 15 Section 3 Galaxies Bellringer What do you think galaxies are made of? What is the name of the galaxy in which we live? Draw a sketch of what you think a spiral galaxy looks like when viewed from outside that galaxy. Record your answers in your Science Journal. < Back Next > Preview Main
Chapter 15 Section 3 Galaxies What You Will Learn • The three types of galaxies are spiral galaxies, elliptical galaxies, and irregular galaxies. • Galaxies are composed of stars, planetary systems, nebulas, and star clusters. • Looking at distant galaxies reveals what young galaxies looked like. < Back Next > Preview Main
Chapter 15 Section 3 Galaxies Types of Galaxies • A galaxy is a collection of stars, dust, and gas bound together by gravity. • Astronomers classify a galaxy as spiral, elliptical, or irregular according to its shape and rate of star formation. < Back Next > Preview Main
Chapter 15 Section 3 Galaxies Types of Galaxies, continued • Spiral galaxies have a bulge at the center and spiral arms. • The spiral arms are made of gas, dust, and new stars that have formed. • The galaxy in which we live is a spiral galaxy called the Milky Way. < Back Next > Preview Main
Chapter 15 Section 3 Galaxies Types of Galaxies, continued • Most elliptical galaxies are round or oval and seem to have stopped making new stars. • Elliptical galaxies are among the largest galaxies in the universe. • Irregular galaxies have no definite shape and form new stars slowly. < Back Next > Preview Main
Chapter 15 Section 3 Galaxies Contents of Galaxies • Some galaxies contain nebulas and star clusters. • A nebula is a large cloud of gas and dust in interstellar space. • Nebulas are a region in space where stars are born. < Back Next > Preview Main
Chapter 15 Section 3 Galaxies Contents of Galaxies, continued • A globular cluster is a highly concentrated group of up to 1 million stars that looks like a ball. • Open clusters are groups of 100 to 1, 000 stars that are close together relative to other stars. < Back Next > Preview Main
Chapter 15 Stars, Galaxies, and the Universe Contents of Galaxies < Back Next > Preview Main
Chapter 15 Section 4 Formation of the Universe Gravity and the Universe • Gravitational attraction caused the matter distributed throughout the universe to form galaxies. • Because gravity acts over such great distances, gravity controls the size and shape of the universe. • Every object in the universe is part of a larger system and gravity acts within each system. < Back Next > Preview Main
Chapter 15 Stars, Galaxies, and the Universe Structure of the Universe < Back Next > Preview Main
Source: https://slidetodoc.com/chapter-15-stars-galaxies-and-the-universe-preview/
0 Response to "Chapter Review Continued Stars and Galaxies Answers Chapter 3"
Post a Comment