Astronomy Final Exam: Chapters 1 & 2 Flashcards
What does the Universe contain?
Everything (all the galaxies)
What is an Astronomical Unit (AU)?
The average distance from Earth to the Sun
What is a light year?
The distance light travels in one year
What is 1 light year?
63,000 AU
What is the order of planets?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune
What are dwarf planets?
Astronomical objects that meet some of the requirements of a planet but not all
What is the composition of the Sun?
Made of hydrogen & helium
When did our solar system form?
4.6 billion years ago
What are star magnitudes?
How bright a star is (energy)
What does the 1st star magnitude represent?
The brightest star
What does the 6th star magnitude represent?
The dimmest star
Why are some star magnitudes negative numbers?
Stars are brighter than the scale because scientific instruments redefined the scale (<1 and >6)
What does the magnitude difference of 5 represent?
Flux ratio of 100
What does the magnitude difference of 1 represent?
2.51 times brighter (other differences is 2.51 to power of difference)
Why do we have seasons?
Due to Earth’s axis tilt of 23.4 degrees
Where does the Sun move during the seasons?
The Sun moves to the northern sky in the spring & southern sky in the fall / winter
What causes day and night?
Earth’s rotation
Dos stars go away during the daytime?
No
What is the ecliptic?
The apparent path of the Sun in the sky (westward motion of the sky = eastward rotation of Earth)
What is angular distance?
Angles between two lines extending from your eyes to two objects
What are angular distance measurements?
Degrees = full circle (360)
Arc Minutes ( ‘ ) = 1 degree = 60’
Arc seconds ( “ ) = 1’=60”
