Chapter+13

Welcome to chapter 13! There is a discussion board at the bottom of the page. Please leave any questions you may have about the chapter, homework, or questions you are struggling with. If you're having trouble accessing the discussion board, please send me an email!

**CHAPTER VOCABULARY** You can participate online by providing explanations for vocabulary in your own words. You can give examples if it helps your explanation of words. You can do one or five or ten and you can add on to posts that have already been made if you would like to improve an explanation. Don't forget to leave your name beside text that you write.

expanding universe- a concept or representation of the universe, based on the observed redshifts of distant galaxies, in which the galaxies are assumed //tmo// be receding from each other at a speed proportional to their separation as a result of the expansion of the universe.(Ashton)

red shift Big Bang theory- a theory that deduces a cataclysmic birth of the universe (big bang) from the observed expansion of the universe, cosmic background radiation, abundance of the elements, and the laws of physics.(Ashton)

light year- the distance traversed by light in one mean solar year, about 5.88 trillion mi. (9.46 trillion km): used as a unit in measuring stellar distances. (Ashton)

parallax baseline

standard candles - **Standard candle** is an unit of luminous intensity. //Matthew Kwak//

absolute magnitude apparent magnitude

nuclear fusion - **Nuclear fusion** is a reaction, two nuclei combine to from a nucleus involving the loss of energy. //Matthew Kwak//

core - **Core** in a solar anatomy contains dense helium, and is placed at the center of the Sun. - Hydrogen fusion occurs in the core. //Matthew Kwak//

radiative zone convective zone

<span style="font-family: Georgia,serif;">photosphere - **Photosphere** is visible surface of the Sun, that is several hundred kilometers thick.

<span style="font-family: Georgia,serif;">//Matthew Kwak//

<span style="font-family: Georgia,serif;">chromosphere - **Chromosphere** is a gaseous layer of the Sun's atmosphere (corona) extending from the photosphere to the corona <span style="font-family: Georgia,serif;">//Matthew Kwak//

<span style="font-family: Georgia,serif;">corona - **Corona** is Sun's atmosphere <span style="font-family: Georgia,serif;">//Matthew Kwak//



<span style="font-family: Georgia,serif;">sunspots - <span class="fnt_e13" style="font-family: Arial; font-size: 12.222222328186035px;">**<span class="fnt_e08 N=a:smd.words">Sunspots ** <span class="fnt_e08 N=a:smd.words" style="font-family: Arial; font-size: 12.222222328186035px;">are dark cool patches that appear on the surface of the sun and last for about a week <span class="fnt_e13" style="font-family: Arial; font-size: 12.222222328186035px;">. //<span style="font-family: Georgia,serif;">Matthew Kwak //



<span style="font-family: Georgia,serif; line-height: 1.5;">solar prominences <span style="font-family: Georgia,serif;">solar flares <span style="font-family: Georgia,serif;">solar wind- an emanation from the sun's corona consisting of a flow of charged particles, mainly electrons and protons, that interacts with the magnetic field of the earth and other planetary bodies.(Ashton) <span style="font-family: Georgia,serif; line-height: 1.5;">main sequence

<span style="font-family: Georgia,serif;">solar mass - **Solar mass** is an astronomical unit of mass equal to the Sun's mass, (1 Solar mass = 19.81 * 1030 kg). //Matthew Kwak//

<span style="font-family: Georgia,serif; line-height: 1.5;">red giant

<span style="font-family: Georgia,serif;">white dwarf

<span style="font-family: Georgia,serif;">neutron star- This is a star that will form if a starting star has 10~ 50 solar masses. This neutorn star's core is so dense that even 150mL of the core weight millions of killograms. (Andrew Park)

<span style="font-family: Georgia,serif;">pulsar- Pulsar is a one type of the neutron star that give out high energy radio waves and light. However they use up all the energy to form a light and fade away. (Andrew Park)

<span style="font-family: Georgia,serif;">black hole <span style="font-family: Georgia,serif;">elliptical galaxies-classified as E0 (the roundest) and E7 (the most elliptical). The names were set by Edwin Hubble according to how spherical a galaxy looked. Elliptical galaxies contain littel or no interstellar matter with rare formation of new stars. (Jordan)

<span style="font-family: Georgia,serif;">spiral galaxies-classified as Sa (tightly wound spiral) and Sc (loose spiral). These galaxies have a number of new stars with an ample of interstellar matter. Our planet Milky Way is a spiral galaxy too. (Jordan)

<span style="font-family: Georgia,serif;">barred spiral galaxies - **Barred Spiral Galaxy** contains an enormous size of straight bar, which is consisted of well defined stars. (Tightly wound = SBa, Loosely wound = SBc) //Matthew Kwak//

<span style="font-family: Georgia,serif;">irregular galaxies - galaxies with no evident shape or outline. These galaxies have no shape and the scientists think they formed due to collisions of galaxies. (Jordan)

<span style="font-family: Georgia,serif;">quasars - A **Quasar** is a star-like object far away in space that produces bright light and radiowaves. //Matthew Kwak//

<span style="font-family: Georgia,serif;">globular clusters- Globular clusters are the clusters of the stars which is the part of the Milky Way. There are tounsands and millions of the star within the cluster and they are tightly held. The Milky Way has approxiamtely 150 of globular clusters. (Andrew Park)

<span style="font-family: Georgia,serif;">open clusters- Open clusters are the cluster that only has few thousand of stars and they agea bout 10~ 30 million. They are called open clusters people they are less tightly held together than the globular clusters. (Andrew Park)

<span style="font-family: Georgia,serif;">dark matter <span style="font-family: Georgia,serif;">dark energy

**<span style="font-family: Georgia,serif; font-size: 17.77777862548828px;">CHAPTER CONTENT ** <span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;">**13.1 The Origin of the Universe**

<span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;">**13.2 Measuring Distance in Space**

<span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;">**13.3 The Birth of Stars, and the Sun**

<span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;">**13.4 Stars: Old Age, Death, and New Life** <span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;"> <span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;">**13.5 Galaxies and Our Home: The Milky Way**

<span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;">**13.6 Dark Energy and the Expansion of the Universe** <span style="display: block; font-family: Georgia,serif; font-size: 16.666667938232422px;">