Stars Science Quest
White dwarfs are roughly the size of......
Earth
5 properties of light we can analyze
-polarization -time -intensity -direction -color
2 big pieces of information from a stars absorption spectrum
1. How much of each element a star contains 2. How fast the star is moving and where it is headed
At what temperature can Hydrogen fuse?
10 million degrees Celsius
The collapsed core of a supergiant star can develop a neutron star which has a diameter of
12 miles across and 1 to 3 times the mass of our sun
What Goldilocks Conditions were necessary for the formation of stars?
A lot of matter, gravity and tiny differences in the distribution of the matter
Microwaves size of
A period
Visible size of
Bacteria
As we look at hotter stars the peak wavelength becomes
Higher. As we look at coller stars the peak wavelength decreases
Soft X-rays size of
Protein
What is pulsar?
Radio waves that a neutron star emits as it spins
What happens to small medium stars the size of our sun?
Swells into red giant. Atmosphere shoots out in a planetary nebula, the core shrinks into a white dwarf and the size of the final core is similar to EP.
Hard x-rays
Water molecule
The hottest stars are....
blue and white, 25,000 and up
Apparent Magnitude -
how bright an object in the sky appears to us. Ptolemy first set this up with 6 levels, or magnitudes. 1 was the brightest and 6 the dimmest. We have since expanded this. Smaller number = brighter! The sun = -27 Full Moon = -12.6 ISS = -6
Luminosity depends on
size and temperature
A binary star system consists of
2 stars that orbit each other. We can tell that it is there because when one passes in front of another we can see the light
How far is the closest star to our Earth, other than the sun
4 light gears away
Our sun has fuel for
5 billion more years
What is the surface temperature of our sun?
5,778 K
What is the name of the only particle that can travel at the speed of light?
A photon
How do elements heavier than iron form?
A supernova creates these elements. It gets extremely hot and everything stars moving extremely fast. The heavier elements start fusing together. The supernova eventually explodes, scattering the elements everywhere.
Why does light from Proxima Centauri shimmy a bit every 11.2 days
Because Proxima Centauri has a planet circling it that gently tugs at the stars atmosphere as it orbits.
Why bigger stars=hotter temperature = shorter life span
Because bigger stars fuse hydrogen faster by squeezing their cores. Since they are burning it faster they live a shoerter life.
Why does our sun look so big.
Because it is the closest to us
Core of Supernova really large might make
Black hole
Infared waves size of
Cell
2 factors that determine how bright a star is to us
Distance, how much light it is emitting
What happens to large stars 4x Times mass of sun
End of life swells into red or blue supergiant, atmosphere shoots out into supernova the core will shrink into a black hole. The size of the final core is the size of a period.
What makes Proxima Centauri difficult to study?
First of it is a flare star which means it regularly gives of x-rays and stellar flares which complicates its shimmy signal. It is also a red dwarf so it allows more chemical elements to absorb energy. This gives of a "Forest of lines" in its spectrum.
What draws Hydrogen and Helium into clouds?
Gravity
What Conditions trigger the process of star formation?
Gravity clumping the more dense areas together. This causes the atoms to bang into each other and the temperature increases to 3000 degrees. The temperature finally reaches 10 million degrees and nuclear fusion takes place. This causes pure energy to be made, and as it stabilizes it becomes a star.
A star is balance of
Gravity trying to crush it and nuclear fusion trying to explode it
How does gravity work?
Gravity works by magnifying the differences between the matter. It's more powerful when their is more mass and less distance. Gravity starts by clumping the slightly more dense area together. As they clump the gravity increases and it keeps increasing. This was gravity's role in star formations.
What did William Herschel's experiment with light and heat prove?
He proved the existence of infared light.
Radio waves size of
House/ soccer field
Absolute Magnitude -
How bright the object really is from a distance of 10 parsecs (about 33 light years). Light follows inverse square law: If distance is doubled, brightness drops by a factor of 22 = 4, if tripled by 32 = 9
After the formation of the first stars most of the matter consisted mainly of.......
Hydrogen and Helium
What happens to a red giant?
In the core of a red giant, Helium is fused into Carbon which is then fused into Neon which is then fused into Oxygen. Meanwhile, the outer sphere of the star continues to fly out into space, forming what is known as a planetary nebula.
What role did stars play in the creation of elements?
In this process stars play the role of creating the really high temperatures needed to make the other elements. A dying star does it best because it burns more Hydrogen and creates a bigger explosion.
What happens to the core of a sun sized star?
It becomes a white dwarf. An extremely dense star. One teaspoon of white dwarf weighs as much as an adult hippo.
Our sun is somewhat rare because
It exists alone
What is the difference between light and sound waves as they travel?
Light waves can travel through a vacuum while sound waves can't. Sound waves need a medium to travel in.
The true amount of light given off by a star
Luminosity
The main part in the life of a star
Main sequence star
Life cycle of a star depends on its
Mass. High mass stars develop and die much more quicker.
Stars form inside a cloud of gas and dust called a
Nebula
Is our sun the biggest star?
No
Nucleosynthesis
Nuclear fusion inside the star creates heavier and heavier elements Energy released by fusion powers a chain reaction of nucleosynthesis Iron is the first element in the chain that takes more energy to fuse than it would release, so the chain stops here. Energy builds up immensely until the star explodes in a supernova. The heat and pressure of the supernova creates elements heavier than iron. The materials released in the superonova eventually form new bodies in the solar system
Stars in order, hottest to coolest
O, B, A, F, G, K, M
Which color has the lowest energy?
Red
Sun will become
Red Giant and then a White dwarf
What do sun sized stars become? (Small- medium)
Red giant
The coolest stars are.....
Red, 8500 degrees
Why do stars get together as galaxies, clusters, superclusters....?
Stars get pulled together as galaxies, clusters and superclusters by gravity. After a superclusters gravity is too weak. This is when we see redshift.
A star 8 times mass of the sun will eventually collapse in a
Supernova
What role do supernova play in the creation of the elements?
Supernova play the role of creating all the elements in the periodic table in one giant explosion. A star can make all the elements up to iron, but a supernova can create them all.
Relationship between temperature and brightness of a star
The brighter the star the hotter it is
Continuous vs. absorption spectrum
The continuous spectrum is all the different wavelengths a star emits and the absorption spectrum is all of the missing spots in the light where the atmosphere has absorbed the light
What about the core left behind after a supernova?
The core of a massive star that is 1.5 to 4 times as massive as our Sun ends up as a neutron star after the supernova. Neutron stars are about 10 km in diameter and have the mass of about 1.4 times that of our Sun. This means that a neutron star is so dense that on Earth, one teaspoonful would weigh a billion tons!
What is the force that holds atoms together?
The force of electrical attraction
What must happen to light in order for an image to form?
The light needs to be focused, and you have to get rid of excess light.
Crazy facts
The more mass a white dwarf or neutron star has the smaller it is. Not even light can escape a black hole
Singularity -
The point in the middle of a black hole where all the matter goes. This point has no 3D volume!
The role of temperature in the formation of matter
The role of temperature- to heat up the universe so that plasma could form and then cool down the universe so that atoms could form.
Schwarzschild Radius -
The size you would have to shrink a particular object down to in order to turn it into a black hole
Event Horizon -
The spherical space around the singularity beyond which nothing can escape.
What happens when large stars reach the red giant phase?
The stars keep fusing together elements, first helium, then carbon then oxygen all the way to iron. At this point, fusion stops and the iron atoms start to absorb energy. This energy is eventually released in a powerful explosion called a supernova. A supernova can light the sky up for weeks. The temperature in a supernova can reach 1,000,000,000 degrees Celsius.
What happens as clouds of Hydrogen and helium get larger?
The temperature gets hotter and hotter and Nuclear fusion starts to take place.
What was different about the universe once the stars arrived?
The universe had light, warmth and density. The stars light up the universe. Now their is also energy from a lot of different spots.
Characteristics of stars that don't follow main sequence trend
They have similar temperatures, but are usually a lot brighter or a lot dimmer
What happens to medium large stars when they die? (1.4x - 4x) our sun
They swell into a red supergiant. Atmosphere shoots outward into Supernova. Core shrinks into neutron star, size of final core is similar to EP
Why did things have to cool down and then heat up again to produce most of what we see?
Things had to cool down first so atoms could form and then heat up after that again in order to produce most of what we see because in order for protons to smash together you need really high temperatures. Most of the elements that we see have very large numbers of protons.
How do stars create elements heavier than helium?
When a star runs out of Hydrogen to form helium the star starts fusing helium together. Everything stars moving faster and getting hotter. The helium fusing together creates carbon.
Spaghettification
When the extreme gravitational force of a black hole stretches and deforms any object that is falling into it.
Our sun is......
Yellow, 5000-6000
Stars produce energy by
nuclear fusion
Longest to shortest wavelength
radio, microwave, infrared, visible, ultraviolet, x-ray, gamma ray
Light moves in a
straight line
What is a light year?
the distance light travels in one year (9.5 trillion km)
How is light measured?
wavelengths, (nanometers) 1 billionth of a meter, 3.937x 10^-8 inches
What is a transit
when a planet crosses in front of a star
