Astronomy Test 2 Study Guide PDF

Stellar Spectrum and Spectral lines LIGHT AND ENERGY - The particular set of lines given off from each element which we view - Visible lines we see without the use of special tech or scopes depend on the temperature of the element we view - Hydrogen only has 3 visible lines - Every at...

Stellar Spectrum and Spectral lines LIGHT AND ENERGY - The particular set of lines given off from each element which we view - Visible lines we see without the use of special tech or scopes depend on the temperature of the element we view - Hydrogen only has 3 visible lines - Every atom, ion, and molecule has a unique spectral fingerprint - The sun is white because it is a mixture of all wavelengths - Neon light produces emission spectrum Thermal Radiation - HOTTER objects emit MORE light per unit area at all frequencies - HOTTER objects emit photons with a HIGHER average energy - Spectral lines are different because of TEMPERATURE - TEMPERATURE and LUMIONOSITY = SIZE SOUND - Doppler shift is the change of frequency when object is moving relative to the observer (THINK FIRETRUCK SIREN VIDEO) - When closer to object that emits sound the frequency will be higher, and when its farther away it will be less - With that in mind, when object is approaching you, the wavelengths will be shorter creating a higher pitch - And with that in mind, as the object passes by you, its wavelength gets longer, and pitch of the sound gets lower - Redshift is the object moving AWAY - Blueshift is the object moving TOWARDS STARS - OBAFGKM (Oh Boy An F Grade Kills Me) STARTS WITH HOT BLUE goes to COLD RED - OBAFGKM determines the temperature of the star with red being the cold and blue being the hot in a scale ranging hotter to colder - The color of a star is determined by its temperature (so OBAFGKM decides the color pretty much) - Mass --> Gravity -->Rate of Fusion-->Luminosity-->Temperature (MGFLT) (My Giant Fox Loves Tacos) - Luminosity is defined as the total energy radiated by a star each second, at all wavelengths - Simpler formula for Luminosity=How luminous the star is, is how hot it is, and determines radius - The DISTANCE to a NEARBY STAR can be measured by observing its PARALAX - Using Parallax, we can observe a star's distance away from us - Bigger stars die quicker than smaller stars because the vast amount of fusion energy occurring - The DENSITY of the star means how much there is per volume - Binary stars are two stars that ORBIT each other - The contraction of a star forming is from nebula and when a star runs out of fuel and dies it's called a supernova - Gamma Ray photons are the particles smashing into each other trying to escape in the stars core (creating nuclear fusion) - If star is very hot its radius will be massive - Stars in ways of chemical composition are all similar, with 70% hydrogen, 28% helium and 2% other elements - If star is too hot, hydrogen will be ionized  - The mass of the star is the most important factor - The BALANCE of the star, is the GRAVITY and the PRESSURE from fusion, making the 'breathing’ affect Features of this graph The main sequence holds stars that are stable like our sun Stars begin as nebula and as they contract and if they have just the right amount of mass and temperature, they begin to form hydrogen gas into helium gas, making the star When star runs out of its fuel (hydrogen) it will differ off the main sequence becoming red super giant, blue super giant, white dwarf THE SUN - The sun is 109 times larger than Earth in diameter - 333,000 times larger than Earth in mass - Hydrogen is converted into Helium in Suns core - Nuclear fusion powers the sun and it happens when atoms smash into each other and fuse together - Photons (light) that escapes the core goes on a path called “The Random Walk”, which refers to the photons colliding with the hydrogen and helium atoms when passing through - Photons then take 8 minutes to travel to us on Earth (93 million miles away) - Plasma is the most common state of matter in the sun - Energy's origins are of positrons and electrons bumping into each other  - Helioseismology is the measuring vibration of the sun - Requirements for Nuclear Fusion are a dense environment and 15 million degrees kelvin Parts of the Sun Inner Parts Outer Parts Core Photosphere - Where Nuclear Fusion occurs - The visible surface of the sun - Where gamma ray photons are - Where light is emitted released - Not solid, made up of gas - Where proton-proton chain reaction - Where sunspots are visible occurs (hydrogen into helium) - 6000 degrees kelvin - 14-15 million degrees kelvin Radiative Zone Corona - The first layer after the core - The outermost layer of the sun’s - 70% of the sun's radius atmosphere - Photons (gamma ray) are absorbed - Much hotter than the photosphere and re emitted by atoms - The source of Solar Wind - Energy is released through radiation - Generates solar flares in this zone Convection Zone Chromosphere - The layer after the radiative zone - Layer below Corona but above - Energy is released through photosphere convection rather than radiation - Cooler than the Corona but hotter - Hot plasma rises to this zone then than the photosphere loses its heat and sinks back down - Where all the magnetic phenomena - Key to energy transport and solar occur magnetic behavior - Where we see solar flares ATOM STRUCTRE - Atom – The building blocks of all matter, composed of positively charged protons and neutral in the nucleus, surrounded by negatively charged electrons - Ground state – The lowest energy state that an electron can have within an atom - Excited state – State of an atom when one of its electrons is in a higher energy orbital than the ground state. Atoms can become excited by absorbing a photon of a specific energy, or by colliding with a nearby atom - Ionized – State of an atom that has had at least one of its electrons removed - Number of PROTONS determines what element it is - A neutral atom is an atom which has the same protons and electrons - Nucleons are inside the nucleus - Isotopes are same number of protons but differ in neutron count - Positron is the positive electron - Neutrinos are small particles with no charge