(Week 10) The graph below illustrates the blackbody curves for both a normal region of the Sun's photosphere and a sunspot. The photosphere is described by which curve?
A
(Week 10) The graph below illustrates the blackbody curves for both a normal region of the Sun's photosphere and a sunspot. The sunspot is described by which curve?
B
(Week 10) Fusion requires high temps in order for nuclei to move quickly enough to:
overcome repulsion (bodies repelling one another)
(Week 10) Fusion requires both high temp & ______ density
high density
(Week 10) Energy is released in proton-proton chain when how many hydrogen atoms are fused into helium?
4 hydrogen atoms
(Week 10) The exterior of the sun, from inner to outermost layers are the following:
Inner - Photosphere
Middle - Chromosphere
Outer - Corona
(Week 10) By watching sunspots, we see that the Sun completes one rotation about every:
1 month
(Week 10) The sun produces the energy that heats our planet by fusing Hydrogen into Phosphate, giving off large amounts of energy. True or False?
False; Hydrogen is fused into helium, giving off large amounts of energy
(Week 10) Sunspots appear dark because they are cooler than the rest of the photosphere. True or False?
True
(Week 10) If one picture shows sunspots and another shows none, how much time likely passed between when they were taken?
6 years
(Week 10) The granulation of the photosphere indicates that energy is being transported upward by radiation. True or False?
False; by convection
(Week 10) Why are Granules on the surface of the Sun dark around the edges?
Cooler material is falling down
(Week 10) Elements in the Sun from most common to least are what?
H, He, metals
(Week 10) The hottest part of the Sun is the what?
Core
(Week 10) The equator of the Sun rotates at the same rate as/slower than/faster than the poles?
Faster than the poles
(Week 10) The corona is hotter than the layers directly below it. True or False?
True
(Week 10) The main sequence on the HR diagram is where 90% of the stars fall, they are stars that are burning H into He, and there's a direct relationship between mass & luminosity. True or False?
True; all of the above
(Week 10) The star Deneb has an apparent magnitude of 1.3 while the star Mimosa has an apparent magnitude of 1.3. Which star appears brighter in the sky?
They appear the same
(Week 10) The star Merak has an apparent magnitude of 2.4 while the star Sirius has an apparent magnitude of -1.5. Which star appears brighter in the sky?
Sirius
(Week 10) The parallaxes (in arcseconds) for four stars are given below. Which star is the closest to us?
Sirius
(Week 10) Spectral classes classify and order stars by what?
Temp
(Week 10) Two stars have the same surface temp. If Star A has a greater luminosity than Star B, then:
Star A is larger
(Week 11) Which cluster is older?
M 67 or NGC 188? Or can you not tell?
NGC 188; the lower the turn off point is where star is just leaving main sequence to move over to Red Giant branch (further down it is on Main Sequence), the older a cluster is
(Week 11) In which stage is the most carbon produced through nucleosynthesis?
Yellow Giant phase
(Week 11) In which stage of the Sun Stages Evolution is the longest?
The Main Sequence
(Week 11) In which stage of the Sun Stages Evolution is the briefest?
Planetary Nebula
(Week 11) In which stage is the most helium produced, or the most hydrogen burned through nucleosynthesis?
The Main Sequence;
definition of Main Sequence is burning H ==> He in the core
(Week 11) In which stage is the star largest physically in size?
The Red/Bright Supergiant
(Week 11) Brown dwarfs are called failed stars because...
they lack the mass to achieve hydrogen fusion
(Week 11) Which of the charts effectively describes the masses with which stars form?
Low-mass (most common/most # of stars)
=> Sun-like
=> high-mass
(Week 11) The clouds that form new stars start out...
Cold
(Week 11) Over time, protostars' luminosity _______ as they decrease in size
decreases
(Week 11) A star's evolutionary path is entirely dependent on its...
mass
(Week 11) Low mass stars have _____ lifetimes compared to high mass stars
longer
(Week 11) What is the end state (solar mass) for a white dwarf?
1-2 solar mass star; more specifically 1.4 solar masses
(Week 11) What is the end state (solar mass) for a supernova/neutron star?
15 solar mass star
(Week 11) A white dwarf will go nova...
when it transfers enough hydrogen from its binary companion star
(Week 11) Elements beyond oxygen, up to iron, are fused...
only in high mass stars
(Week 11) Iron is not normally fused in stars because
iron fusion absorbs energy
(Week 11) The interstellar medium is enriched with elements heavier than iron by...
supernova explosions
(Week 11) After it leaves the main sequence a star like the Sun will become a...
Red giant
(Week 11) A star like the Sun expels its outer layers to form a...
planetary nebula
(Week 11) What holds a white dwarf up against collapse by gravity?
electron degeneracy pressure
(Week 11) How do stars more massive than the Sun fuse hydrogen into helium?
CNO cycle (Carbon, Nitrogen, Oxygen)
(Week 11) What properties fall under Supernova Type Ia?
--Runaway fusion of White Dwarf in Semi-detached binary
--Leaves behind no compact stellar remnant
--Has no Hydrogen lines in Spectrum
(Week 11) (Week 11) What properties fall under Supernova Type II?
--Massive Star with Iron Core
--Core collapse of massive star
--Leaves behind a Neutron Star or Black Hole
--Has Hydrogen lines in Spectrum
(Week 11) Fusion reactions in a type Ia supernova or type II supernova produced the:
gold and silver in Earth's crust
(Pop Quiz #3) What star group is in location A in the Schematic HR Diagram?
White Dwarfs
(Pop Quiz #3) What star group is in location B in the Schematic HR Diagram?
Main Sequence
(Pop Quiz #3) What star group is in location C in the Schematic HR Diagram?
Red giants/supergiants
(Pop Quiz #3) What element do stars fuse for the longest phase of their lives?
Hydrogen
(Pop Quiz #3) The Sun will one day explode as a supernova. True of False?
False
(Week 12) What holds a White Dwarf star from collapsing against gravity?
Electron degeneracy; electrons push as close together as they can between nuclei making up the White Dwarf
(Week 12) What holds a Neutron Star up against collapse by gravity?
Neutron Degeneracy Pressure; neutrons packed together as close as possible without occupying same space -- Max mass it can support is 2-3 M☼ (known limit definitely not 3)
(Week 12) What would happen if a Neutron Star were to collapse?
Singularity; it would collapse to an infinitely small size with infinite density
(Week 12) If a black hole has a bigger mass & smaller radius, would it have less or greater Escape Velocity?
Greater Escape Velocity; fyi, singularity has NO SIZE
(Week 12) When it comes to the size of a Black Hole, the radius is not the size of the singularity, but the singularity + surrounding area DOES have a radius. True or False?
True; R = 14.8 km
This distance/radius is the "Schwarzschild radius" --- surrounding the radius/border is "event horizon"
(Week 12) A ______ w/ a companion star can have a glowing x-ray accretion disk.
--Neutron Star
--White Dwarf
--AND Black Hole all can have this
(Week 12) If you were to enter the Event horizon of a Black Hole, velocity would be ________ than speed of light. Stay outside, escape velocity ______ speed of light
Greater than
Less Than
(Week 12) Evidence of a black hole in a binary system would be:
A mass greater than 5 Solar Masses
If a Black Hole is NOT Binary, there's still other ways of detecting it. True or False?
False; virtually no way of detecting it (both Gravity & X-ray Accretion disk methods FAIL)
(Week 12) Which properties/objects fall under the Stellar Population I?
Metal-rich
Disk component
Sun
Open cluster
Young
(Week 12) Which properties/objects fall under the Stellar Population II?
Metal-poor
Halo
Bulge
Globular Cluster
Old
(Week 12) What property falls under this component of our galaxy?: Disk
Active star formation
Sun
Spiral arms
(Week 12) What property falls under this component of our galaxy?: Spherical/Bulge
Dark matter
Random, eccentric orbits
Old stars
(Week 12) What is the best evidence for a Supermassive Black Hole in the Milky Way's core?
The orbits of the stars that are nearby to it
(Week 12) The Milky Way's globular clusters are centered on the _______ ______.
Galactic Bulge
(Week 12) "Dark matter" is so named because it:
exerts gravitational forces but is less luminous than stars, gas, and dust
(Week 13) Spiral galaxies contain what components? Disk, Spherical, or Both?
Both Disks & Spherical
(Week 13) Elliptical galaxies contain what components? Disk, Spherical, or Both?
Spherical
(Week 13) Irregular galaxies contain what components? Disk, Spherical, or Both?
Neither
(Week 13) The larger the galactic bulge, the _______ the central black hole
Larger
(Week 13) What settled the debate on whether or not "spiral nebulae" were inside the Milky Way's boundaries?
Distance to M31 (Andromeda) found w/ Cepheid Variables
(Week 13) Which types of galaxies usually experience active star formation?
Irregular & Spiral
(Week 13) When galaxies collide, their individual stars rarely do. True or False?
True
(Week 13) Define the characteristics of Ellipticals
No flattened Disks
No Spiral Arms
Not much structure
Mostly contains old stars (Red & Yellow colors)
No cool gas or dust
(Week 13) Define the characteristics of Spirals
Spiral Arms which contain hot, young (blue) stars
Considerable amount of cool gas & dust
(Week 14) This distance between the Milky Way and the Andromeda Galaxy is...
decreasing due to motions in the Local Group
(Week 14) Hubble and other astronomers discovered that all distant galaxies are...
redshifted
(Week 14) The galaxy at the core of a well-populated (rich) cluster is most likely a(n)...
Elliptical
(Pop Quiz #4) What kind of object(s) reside(s) in the halo of the Milky Way?
--Globular Clusters w/ eccentric orbits
--Mostly Old Stars
--"Metal" Poor (less than 0.1)
(Pop Quiz #4) The disk of the Milky Way contains ________ stars.
young
(Week 15) Olbers' Paradox indicates that the Observable Universe has...
--A Finite Age
--A Finite Size
(Week 15) Gravitational lensing allows us to probe the lensing galaxy's...
mass
(Week 15) What properties determine if the universe will expand forever?
--Amount of Dark matter
--Amount of Dark energy
--Amount of Normal matter
(Week 15) Over time the universe has gotten...
Bigger, cooler, less dense
(Week 15) Today's universe is _____ dominated.
matter-dominated
(Week 16) Which type of star would be least likely to have a planet that could support life?
High mass Star
(Week 16) Habitable zones are the regions...
around a star where water on the surface of a planet is likely to be liquid
(Week 16) Even though the Moon is in the habitable zone for our solar system, why is there no life there?