Astronomy

Definitions Rotation – An object circling 360 degrees around _____________ Revolution – An object circling 360 degrees around _________________ Day – One Earth ______________ Year – One Earth _________ around sun Month – One moon __________ around Earth

Radio Telescopes Microwave Telescopes Infrared Telescopes Gamma Ray Telescopes UV Telescopes X-Ray Telescopes Telescopes

Reflecting versus Refracting Reflecting Advantages 1.Focuses ________ images 2.No ___________ of color 3.Can make very big to collect more _______ and see farther. 4.Easier and _________ to make mirrors. 5.Less ______ to carry around. Disadvantages 1.Mirror needs to be _______ of dust or particles 2.Image can be reversed (mirror image) Refracting Advantages 1.Can see clear details in ________________ from planets and moons. 2.Cheap to make on ____ scale Disadvantages 1.As they get larger lenses get very __________. 2.Lenses need to be _________. 3.___________ color images as they pass through lens. 4.____________ on large scale. 5.Lens sags under its ________ Better Overall Telescope: __________ Telescope

Light Year A measure of _____________ Distance light travels in ________ What is it? So are we looking at the past? ________________

We are! Imagine looking at a star 30 LY’s away. What does that number mean? For an object 30 LY’s away it takes light 30 years to travel to your eye. How old would you be? For an object 130 LY’s away it takes light 130 years to travel to your eye. How old would you be? For an object LY’s away it takes light years to travel to your eye. How old would you be?

Light Years If a star is 30 LY’s away and the light left that star today it would not arrive at your eye for _______. (So, what you are looking at is ______________________!!)

Spectroscopy

Examples strasbg.fr/~koppen/discharge/

Doppler Effect Objects moving ____________appear blue or blue shifted Objects moving ____________appear red or red shifted

Doppler Effect in Action

Star Composition Stars made of ____________ ______ is the fuel which turns into ________ __ + __ __ + Energy

Star Temperature ColorTemperature BlueAbove 30,000 C Blue white7,500 – 30,000 C Yellow-white6,000 – 7,500 C Yellow5,000 – 6,000 C Orange3,500 – 5,000 C RedLess than 3,500 C

Apparent Magnitude How bright a star ____________ to be Depends on _______, _____, and ______ output What is the brightest star?

Absolute magnitude _________ brightness of a star Depends on star’s actual brightness at a distance of ______ light years away. Astronomers use this type of magnitude as it is more _________.

Measuring Magnitude Sun Sirius A Krugar A Apparent Absolute The more _________ the magnitude the brighter the star

Parallax An __________ shift in the position of the object when viewed from __________ locations. Complete quick lab on page 37 to further explain.

Parallax

Star Motion Stars appear to move around Polaris. Why? Stars actually move, but they are so far away it is hard to tell. Looks like Figure 8 on page 38

Hertzsprung Russell Diagram

Sun Like Stars or Main Sequence Blue Giants Blue Supergiants Red Dwarf Brown Dwarf

Life Cycle of a Galaxy From Youngest to Oldest 1. ___________________ 2. ___________________ a. ___________________ b. ___________________ 3. ____________________ a. ___________________ b. ___________________ c. ___________________

Formation of the Universe

______________ Theory 1. All the matter and energy in the Universe was once concentrated into a ____________. 2. An explosion shot the concentrated matter and energy in all directions ______________________.

Big-Bang Theory and Evidence 1. _______________________ everywhere 2. 99% of Galaxies _____________ 3.Farthest galaxies continue to move _________________

Big-Bang Theory Alternatives ____________ Theory: Split second after big bang universe rapidly inflates and eventually slows down. Supports BB ___________Theory: Boring because it says we will continue to expand. Supports BB _____________: End of BB will cause dark matter to pull universe back together due to strong gravity. Supports BB _____________: Expansion of universe will slow and cease and stay steady after that. Supports BB.

Big-Bang Theory Alternatives ______________ Theory: Universe was and will always be as it is currently. No expansion/contraction. Refutes BB ____________ Theory: Universe covered with plasma that when electrified or magnetized created stars, galaxies, and all matter. Refutes BB _______________Theory: Long super massive strings created by gravitational shifts and contain mass of 1000’s of galaxies. These are barriers between different space-time regions. Refutes BB