[Science 2] Astronomy Flashcards
What are stars?
Astronomical objects that create their own energy and light
What are planets (how are they connected to stars)?
Moves around a star along a certain orbit and does not emit light.
What are Natural Satellites?
Astronomical object that is revolving around a planet (ex. Moon)
What is a star cluster?
Assembly of stars
What are the differences between Open Clusters and Globular Clusters in a Star Cluster?
Open: Blue-white stars in milky way
Globular: Ball-shaped clusters containing red stars outside the milky way
What is an area with a high concentration of dust and gas?
Nebula
What is a galaxy?
A collection of stars, planets, satellites, star clusters, and nebulae.
What is an external galaxy?
Other galaxies outside of the Milky Way
What is 1 Astronomical unit (AU)?
Average distance between the Earth and the Sun
With Hipparchus’s scale of the brightness of stars (apparent magnitude), how much is each magnitude step?
2.5x (largest is 100 in brightness)
What was the problem with apparent magnitude? What did they replace it with?
Did not consider the distance of the stars (faint stars near Earth can also be seen as bright)
Absolute magnitude
What does absolute magnitude measure?
How bright a star appears at a distance of 32.6 ly (Alpha Centauri) from Earth
What are the color of stars measured by?
Surface temperatures (If higher –> look more blue)
What can stars be classified into in absolute magnitude? What are their properties?
Main sequence stars (most stars), Red Giants (bright with low temperature), White Dwarfs (faint with high temperature)
What are colors are Antares, Betelgeuse and Aldebaran?
Red stars
