ASTR 1000 Study Guide - Summer 2018, Comprehensive Midterm Notes - Earth, Venus, Sun
12 Oct 2018
School
Department
Course
Professor
ASTR 1000
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Class 1 & 2
What dates does the year start? Jan 1st! But a long time ago it used to be March 25th.
Units
1. Astronomical Unit (au)
- Average distance of the earth from the sun.
2. Light-year (ly)
-unit of distance not time
-measures how far light travels in one year
-300,000km/s * seconds in one year = 9,000,000,000km
3. Parsec (pc)
-the only measurement that is used with normal distance… for example kpc or mpc
-it is a bit bigger then ly
-30,000,000
-1pc = 3.2 ly
-comes from measuring stars
Notes about the Universe:
-Most of the universe (vast bulk) is unobservable to us
-Galaxies are not randomly distributed, they are found in sheets, voids etc
-We are located in the outer part of the milky way galaxy - dust and gas is found here
-These are known as MODELS of Atoms, bottom left is closest to the actual look of an atom.
find more resources at oneclass.com
find more resources at oneclass.com
Constellations
-A human grouping of stars in the night sky into a recognizable pattern.
-Essential a model of how we perceive the nighttime sky
Orion
Celestial Sphere
-Imaginary sphere surrounding earth to which all objects
in the sky were considered to be attached.
Celestial Pole
- Projection of Earths North and South pole onto the
celestial sphere.
Celestial Equator
- The projection of Earths equator on the celestial sphere.
Measurement/ Angles in Astronomy
1. Latitude (aka declination)
-North or South of Celestial Equator
--90° —> 0° —> +90°
2. Longitude (aka Right Ascension)
--180° —> 0° —> +180°
-0hrs —> 12hrs —> 24hrs
-measured in units of time
1° = 60’arc minutes = 3600’’
1’ = 60’’ arc seconds
The big dipper is NOT a constellation,
it is actual a alsteration
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
But a long time ago it used to be march 25th. Average distance of the earth from the sun: light-year (ly) Measures how far light travels in one year. 300,000km/s * seconds in one year = 9,000,000,000km: parsec (pc) The only measurement that is used with normal distance for example kpc or mpc. It is a bit bigger then ly. Most of the universe (vast bulk) is unobservable to us. Galaxies are not randomly distributed, they are found in sheets, voids etc. We are located in the outer part of the milky way galaxy - dust and gas is found here. These are known as models of atoms, bottom left is closest to the actual look of an atom. A human grouping of stars in the night sky into a recognizable pattern. Essential a model of how we perceive the nighttime sky. The big dipper is not a constellation, it is actual a alsteration.
