PSU Astro 7N Exam 2

What gases make up the sun?

What causes sunspots?

What is made from 4 protons during fusion in the sun?

Step 1 of P-P Chain What forms when two protons collide at very high speeds?

Step 2 of P-P Chain When deuterium and a proton collide it makes this

Step 3 of P-P Chain Two Helium-3 nuclei combine to make this

1 proton and 1 neutron bound together

2 protons and 1 neutron

2 protons and 2 neutrons

Central part of sun High density and temperature Nuclear reactions occur here Gamma rays are produced here

Region in sun Photons are re-absorbed and re-emitted

Region of the sun where gases circulate Light takes a week to get through

The surface of the sun that we see

Red/orange We see through it

An eruption coming out of the sun due to magnetic activity

Hoop-shaped eruption out of the sun due to magnetic activity

Outer layer of sun Low density Only visible during solar eclipses

The true brightness of the star The absolute power output

Apparent output of something observed at a certain distance

B=L/(4pi(d^2))

If star A is (X) times as luminous as star B, then stars A and B would appear equally bright if star A were 2 times as far away as star B

D=1/p D= Distance in parsecs p= Parallax angle in arc seconds (1/3600)

What color are cooler stars?

What color are hotter stars?

The temperature sequence (from hot to cold) of spectral classes

The closest star to our solar system other than the sun 4.3 light years away

Brightest star in the sky

Which stars are located on the lower right of the HR Diagram? Cool, faint, small

Which stars are located on the upper left of the HR Diagram? Hot, bright, large

Not on the main sequence Burning helium and other elements in their cores (not hydrogen) Starting to die Large and very luminous Cooler Top right of HR DIagram

Sun's History

Ejected envelope (the layers of the core) of a low to intermediate mass star

End state of a star's core About the size of the Earth

Failed stars Don't heat up enough to have nuclear reactions in their core

When a massive star burns through hydrogen and then helium and then more massive elements it leaves behind layers Concentric shells of fusion zones involving different chemicals

Stable element that stops the burning of a star

Violent explosion with the star's core left behind Creates an environment for the fusion of elements heavier than iron to form

Spherical boundary around a black hole where nothing can escape Escape velocity of this area is faster than the speed of light

A point of infinite density

Method to estimate the number (N) of communicating/technological civilizations in our Galaxy

The number of intelligent and communicating civilizations in the Milky Way Galaxy

The rate of formation of habitable stars in the galaxy

Fraction of stars in R* that have planetary systems

The average number of Earth-like planets in the Fp systems

Fraction of planets from Ne in which life develops

Fraction of plants with life that eventually gives rise to intelligent life

Fraction of intelligent species that are capable of interstellar communication

Average lifetime of communicating civilizations

P2=a3

Stars born with less than about 2 solar masses of material Very long lifetime

Around a few times the Sun's mass Tens/hundreds of millions of years lifetime

Stars born with masses greater than about a few tens of solar masses A few million years lifetime

Becomes a planetary nebula during the end stage of its life

Becomes a Type II Supernova during the end stage of its life

Leaves behind a white dwarf thats roughly Earth sized

Leaved behind a neutron star thats roughly city sized

Leaves behind a black hole that is an infinitesimally-small point

Hundred/thousands of stars that formed at the same time Only bound by gravity for a few million years Tend to have lots of blue stars

Hundreds of thousands/millions of stars Tend to be more yellow in color with many red giants

When a low-mass star runs out of core nuclear fuel Blows off outer layers in a pulsating/layer look Often Symmetric White dwarf is left in the center

Caused by a binary star Light echo pattern Involves two stars revolving around each other Sudden brightness that can occur multiple times

Occurs when massive stars die Leads to neutron stars or black holes Contain prominent Hydrogen lines

Occurs when large amounts of material are suddenly added to a white dwarf from a binary companion Do not contain Hydrogen

Where stars form Contain several million times the Sun's mass

If the mass is greater than this, it will collapse If the mass is smaller than this internal pressure dominates and it doesn't collapse

The mass of the sun

Component of the Milky Way 100K lightyears in diameter Spiral pattern Blue stars dominate this region

Spherical region in the center of the disk Yellow color

Large spherical region around the whole galaxy Contains old stars Globular clusters exist here

Have more gas, dust, and star formation than other kinds of galaxies Noticeable disks

More yellow color Largest galaxies are this type

Spiral galaxy with a central bar

Elliptical galaxy with a circular shape

Elliptical galaxy with an elongated shape

Cannot be classified as either a spiral or elliptical galaxy

The shifting of the lines in the spectrum of an object to longer wavelengths, due to its motion away from the observer

A Doppler shift in which spectral features are shifted to shorter wavelengths, observed when an object is moving toward the observer

Z=(Observed-rest)/Rest

V=redshift*speed of light

The observation that the farther away a galaxy is, the faster it is moving away. V=Ho*D V= velocity of recession Ho= Hubble's constant D= Distance to galaxy

Unknown particle that hasn't been discovered yet Emits no form of radiation We only know about it through the gravitational influence of its mass

An object with a known luminosity EX: Type Ia Supernovae

Is the expansion of the universe accelerating or slowing down?

A sort of "anti-gravity" causing the acceleration o the universe Comprises about 71% of the overall density of the Universe

Everything we can see in the Universe that is made up of atoms

Quarks, leptons, bosons Cannot be broken down into smaller units

Up, down, charm, strange, top, bottom They all have anti-quarks as well

Include electrons and neutrinos 6 types and 6 anti-types

2 up quarks 1 down quark

2 down quarks and 1 up quark

Each quark in a particle needs to have different __________

How many types of fundamental particles are there?

Carry forces

Gravity, electromagnetic force, strong force, weak force

Have not been discovered yet but are thought to be the bosons that carry the force of gravity and act on mass

Carry the electromagnetic force Act on electric charge

Bosons that carry strong force Hold atomic nuclei together

Carry the weak force Responsible for radioactive decay

Quarks form Quarks bind together into protons and neutrons P/N bind together to form helium nuclei (nucleosynthesis); universe is still opaque Electrons join with nuclei to form complete atoms; universe is transparent Stars and galaxies form First large stars die and spread heavier elements Quasars form

Remains of a more massive star At the center could be a neutron star Exploded appearance

Huge clouds of cool gas and dust New stars form here Dominated by pink tones