ASTR 1050 Exam 1 Study Guide

These are the course topics addressed on Exam 1.

Standard 1.  Describe and explain how the sky changes throughout the day, month, and year.

• Solar and sidereal days
• Synoptic and sidereal months
• Phases of the Moon
• Sidereal and tropical year
• Seasons
• Perihelion and aphelion

Standard 2.  Identify and describe schemes for specifying locations in the sky.

• Constellations
• Coordinate systems (definitions, advantages, disadvantages)
  • altazimuth
  • equatorial: RA, decl
  • ecliptic
  • galactic
  • ICRS

Standard 3.  Identify the characteristics of, and conditions creating, Solar and Lunar eclipses, planetary transits, and occultations.

• Conditions of alignment
• Parts of the shadow
• Angular sizes of Sun and Moon at perigee, apogee, perihelion, and aphelion
• Types of eclipses

Standard 4.  Describe the orbits of the planets, including direction and shapes of their paths.

• Earth spin and orbit
• Orbital directions of Moon and planets
• Kepler’s laws
  • elliptical orbit, Sun at one focus
  • T² = a³
  • equal area law

Standard 5.  Explain and apply Newton’s formula for the gravitational force.

• F = Gm₁m₂/r²

Standard 6.  Explain evidence supporting the heliocentric model of the Sun and planets.

• Occam’s razor: a simpler explanation is preferred over a complex one
• Celestial distances: stars are too distant to circe Earth daily
• Kepler’s laws: heliocentric, not geocentric
• Newton’s formulation of gravity explains Solar System dynamics