Star Systems and Galaxies Sect. 4 Made by: Alberina Dreshaj, Anna Doucette, Michayla Anja, and Chelsea Merrill.

Binary Star Star systems that have two stars.

Open Clusters A star cluster that has a loose, disorganized appearance and contains no more than a few thousand stars.

Eclipsing Binary A system in which one star periodically blocks the light from another star.

Globular Clusters Large groupings of older stars.

Galaxy A huge group of single stars, star systems, star clusters, dust, and gas bound together by gravity.

Spiral Galaxies Galaxies with bulges in the middle and arms that spiral outward, like pinwheels.

Elliptical Galaxies Galaxies that look like round flattened balls.

Irregular Galaxies Galaxies that do not have regular shapes.

Quasars An enormously bright, distant galaxy with a giant black hole at its center.

Universe All space and everything in it.

Scientific Notation A mathematical method of writing numbers using powers of ten.

3 Objectives Objective number 1: Define a star system. A star system is a group of 2 or more stars.

Objective number 2: Identify the major types of galaxies. The major types of galaxies are spiral, elliptical, and irregular.

Objective number 3: Explain how astronomers describe the scale of the universe as all of space and everything in it. Astronomers describe the scale of the universe as all of space and everything in it by studying everything in it such as objects as close as the moon and as distant (far away) as quasars.

Checkpoints and Figures! Interpreting Diagrams- Algol appears brighter when the dim star of the binary star passes in front of the brighter star and eclipses it.

More checkpoints! Checkpoint- Globular clusters are large groupings of older stars. Checkpoint- A quasar is an enormously bright, distant galaxy with a giant black hole at its center. Interpreting Diagrams- The sun is located halfway out from the middle. Checkpoint- About 25,000 light-years. Calculating meters.

Sect 4 Assessment. 1.a) A binary star is a star system that has 2 stars. b) Yes, because each star system has 2 stars that are called double stars or binary stars. c) The term is appropriate because when the dim star goes in front of the brighter star, it is eclipsing it and there are 2 stars. 2.a) Spiral, Elliptical, Irregular. b) The milky way is a spiral galaxy. c) Elliptical. 3.a) The scientific notation is a mathematical method of writing numbers using power of 10. b) How the scientific notation is useful to astronauts is it helps them determine light-years. c) The Cat’s Eye.

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