stars and galaxies terms

temperature, hot to cold

on the HR diagram, the x axis contains _______, and it runs ________.

luminosity

on the HR diagram, the y axis is ______ and it increases as it goes up.

bigger

if a point moves up or to the right on the HR diagram, the star is _______ in diameter

smaller

If a point moves down or to the left on the HR diagram, the star is ______

main sequence

_______ _______ stars are in a state of hydrostatic equilibrium, where the inward force of gravity is precisely balanced by the outward pressure from the energy released by fusion. They are in the longest and most stable phase of their life cycle, fusing hydrogen into helium in their cores to generate energy. placing them in a distinct band on the Hertzsprung-Russell diagram the ZAMS.

upward

The stars on Main sequence evolve slowly ______ during their Main Sequence lifetime

composition, mass

the position of a star on the HR diagram is based on its ______ and its _____.

white dwarf

If the residual core mass is less than the Chandrasekhar Limit , then the core is held up against gravity by electron degeneracy and it becomes a _____ ______.

white dwarf

below the Chandrekhar Limit (1.4 solar masses) supported by electron degeneracy pressure, composed of carbon and oxygen from helium burning

supernovae, neutrinos, neutron star

when the residual core mass is between 1.4 and 3.4 solar masses, it will collapse creating a ________, when protons and electrons can form neutrons and _______. The reminant is a _____ ____, which is stabilized 

black hole

when the residual mass is more than the chandreskhar limit of 3.4 then the mass slips below the scharzschild radius and becomes a

space time

the _____ ____ diagram depicts the limitations of relativity

world line

on the space-time diagram we are currently on a _____ ____ in the present, theremay be an elsewhere that we never meet.

post main sequence stage

the formation and contraction of a pure helium core causes the star to expand in the initial

helium flash

the overlying envelope becomes convective, the hydrogen brought down to the burning helium core, causing a rapid rise in luminosity and ignited the triple alpha process burning helium into carbon in what is known as the _____ _____.

asymptotic giant branch

This phase is characterized by mass loss and pulsations. with increasing carbon ash, the star climbs a second red giant branch, more massive stars commence, burning heavier elements (up until iron)

AGB, variable

stars on the ____ are subject to envelope ejections which form planetary nebulae and in some cases go through ______ star phases.

Cepheid Variables

_______ ______ are variable stars that have a period luminosity relationship that is useful as a distance measuring tool.

RR-lyrae stars

population 2, on the Horizontal Branch exhibiting regular oscillations, often older with lower metallicity

Bosons

force carriers

fermions, bosons

_________ obey the Pauli exclusion principle, while _____ do not

half, whole

fermions have a ____ integral spin, bosons have a _____ integral spin.

boson

is gravity a fermion or boson?

population 2

stars with low element abundances (less than 0.1%)

population 1

heavy stars with high element abundances (above 0.5%)

1

The sun is a population ___ star, as are most nearby stars in the milky way.

neutrinos

when supernovae explode they give off a large amount of light. But in the observations of supernova 1987(In the large megellanic cloud) it showed that the supernova gives off more energy in the form of _______.

solar neutrinos

are subatomic particles produced by nuclear fusion in the Sun's core that travel through space to Earth at nearly the speed of light. They have no electrical charge, are extremely light, and interact very weakly with matter, allowing them to pass through the Sun and Earth without being deflected or absorbed.

supernovae

after the core of a star becomes a neutron star, the rest of the stars material explodes into a ________.

special relativity

deals with relative motion and the relationship between time and space,There is no special, absolute rest stop in the universe. If you are floating in space and another person zips past you, there's no way to say who is "really" moving and who is "really" standing still. All constant motion is relative.The speed of light is the ultimate speed limit of the universe, and it is constant for every observer

result: time appears to run slower and length is shorter in moving frames. E=mc², mass increases with the speed.

general relativity

space time is curved by energy. gravity is not a force. Light moves in straight lines, stright lines are bent in curved space time.

postulate 1

the laws of physics are independent of the observers frame of reference (special relativity)

postulate 2

the speed of light is always the same for every observer (special relativity)

red giant branch

a stage in the life of a medium to massive star where it expands dramatically after exhausting the hydrogen fuel in its core. As the core contracts and heats up, it ignites hydrogen fusion in a surrounding shell, causing the outer layers to swell and cool, which gives the star its reddish-orange hue and increased luminosity

AGB, RGB

The ___ phase is shorter and more luminous than the ___ phase, and it is characterized by thermal pulses and more significant mass loss. 

red, asymptotic

The main difference is that the ___ giant branch is the earlier stage of evolution for low- to intermediate-mass stars where hydrogen fuses into helium in a shell around an inert helium core, while the ________ giant branch  is a later stage, where stars have a more complex structure with both a hydrogen-fusing shell and a helium-fusing shell around an inert carbon and oxygen core

helium, carbon oxygen

RGBs have a ____ core, while AGBs have a ____ _____ core

higher

AGB has a ____ luminosity than the RGB

s-process nucleosynthesis

is the slow neutron-capture process in stars that creates heavy elements like silver, gold, and lead by slowly absorbing neutrons into atomic nuclei. This process mainly occurs in asymptotic giant branch

r-process nucloesynthesis

a rapid neutron-capture process that creates many of the heavy elements heavier than iron

Ni, Co

When a Type II Supernova is

seen, its “light curve” (its

brightness as a function of

time) shows the

characteristic decay times of

elements like __ and _

brown dwarf

A "failed star" or an astronomical object that never fully started. Never hot enough to sustain normal hydrogen fusion.

winding up, magnetic field

the sunspot cycle is caused by the _____ of the suns ___ ______.

11,22

every __ years the magnetic field is wound up and inverts itself, giving a — year net cycle.

2

sunspots are caused by magnetic field loops protruding, they come in groups of __

further, closer

sunspots occur ____ from the suns equator in the earlier cycle and ____ towards the end

twisted field lines

Flares are caused by ____ ____ ____.

coronal mass ejections

_____ ____ ______ are caused by high fluxes of particles

differential rotation

the sun rotates faster at the equator than the poles

core

1. Suns innermost layer, source of energy and heat

2. 15 MillionK

3. Density: 160

4. Luminosity= the surface luminosity

radiative zone

2nd layer of suns interior, energy is transported by ?

it takes hundreds of thousands of years to traverse due to opacity (thickest layer)

convective zone

3rd layer of suns interior, energy is transported by ?

rising hot bubbles reach the photosphere and cause granulation

photosphere

4th layer of the sun, innermost layer of atmosphere, 99% of light

photosphere

absorption spectrum occurs in the

chromosphere

the emmission spectrum occurs in

chromosphere

5th layer of the sun, middle layer of the suns atmosphere. Emission spectrum, ragged upper transition layer

chromosphere, transition zone

The ___________ starts at the coolest point in the Sun’s atmosphere and extends upwards until the temperature rises rapidly into the ___________. The reason for the rapid climb in temperature is likely magnetic heating in the upper layers.

corona

6th layer of the suns atmosphere, contains 9 prominences. very low density, high temperatures, contains 2 spectra- F Corona(scattered photospheric light) and K Corona(hot electrons radiating a continuous spectrum)

k,f

_-corona are hot electrons radiating through a continuous spectrum

_-corona are scattered photospheric light