Question

Could someone help me in my relearn 2.00 for my oral Exam.
The distances in the universe
The physical appearance of the sun
How the electromagnetic spectrum is used to study stars and planets

Answer 1

Those are the categories of things you need to know?

Answer 2

Yes It is

Answer 3

I really need help cuz I have to do it before 8 PM

Answer 4

The big bang theory had to do with the universe expanding.

Answer 5

Ok

Answer 6

It is considered to be the origin of space and time. Everything being created from the energy released by it

Answer 7

Ok so the next one please.

Answer 8

@sarahh134 What happend?

Answer 9

@GIitter Help me please.

Answer 10

Sorry my internet is giving me problems but I honestly am not 100% on the other topics. I don't want to give you the wrong information.

Answer 11

Oh ok thanks though

Answer 12

You're welcome.

Answer 13

@mely1014

Answer 14

ok let me find out about properties of stars

Answer 15

ok

Answer 16

•Luminosity: distance combined with apparent brightness.
•Distance: trigonometric parallax.
•Diameter: Luminosity combined with temperature.
•Mass: Binary star orbits and Kepler's Laws.
•Composition: Spectra.
this is some

Answer 17

Ok

Answer 18

the stages of a stars life

Answer 19

Wiat didnt u skip some?

Answer 20

Stage 1- Stars are born in a region of high density Nebula, and condenses into a huge globule of gas and dust and contracts under its own gravity.

Stage 2 - A region of condensing matter will begin to heat up and start to glow forming Protostars. If a protostar contains enough matter the central temperature reaches 15 million degrees centigrade

Stage 3 - At this temperature, nuclear reactions in which hydrogen fuses to form helium can start.

Stage 4 - The star begins to release energy, stopping it from contracting even more and causes it to shine. It is now a Main Sequence Star.

Stage 5 - A star of one solar mass remains in main sequence for about 10 billion years, until all of the hydrogen has fused to form helium.

Stage 6 - The helium core now starts to contract further and reactions begin to occur in a shell around the core.

Stage 7 - The core is hot enough for the helium to fuse to form carbon. The outer layers begin to expand, cool and shine less brightly. The expanding star is now called a Red Giant.

Stage 8 - The helium core runs out, and the outer layers drift of away from the core as a gaseous shell, this gas that surrounds the core is called a Planetary Nebula

Stage 9 - The remaining core (thats 80% of the original star) is now in its final stages. The core becomes a White Dwarf the star eventually cools and dims. When it stops shining, the now dead star is called a Black Dwarf.

*This is for small stars*

Answer 21

Wait didnt u skip some..

Answer 22

yeah, im doing the ones i know

Answer 23

Oh ok. Thanks

Answer 24

*This is for big stars*

Massive stars have a mass 3x times that of the Sun. Some are 50x that of the Sun

Stage 1 - Massive stars evolve in a simlar way to a small stars until it reaces its main sequence stage (see small stars, stages 1-4). The stars shine steadily until the hydrogen has fused to form helium ( it takes billions of years in a small star, but only millions in a massive star).

Stage 2 - The massive star then becomes a Red Supergiant and starts of with a helium core surrounded by a shell of cooling, expanding gas.

Stage 3 - In the next million years a series of nuclear reactions occur forming different elements in shells around the iron core.

Stage 4 - The core collapses in less than a second, causing an explosion called a Supernova, in which a shock wave blows of the outer layers of the star. (The actual supernova shines brighter than the entire galaxy for a short time).

Answer 25

The parts of the universe

The directory of observable objects in the universe is vast. The smallest components are atomic particles followed by atoms (mostly free hydrogen and helium), molecules, dust, space rocks, comets, asteroids, moons, dwarf planets, planets, solar systems, stars, black holes, nebulae, and galaxies.

Answer 26

anything eles?

Answer 27

Characteristics

The Sun consists of about 70% Hydrogen, 28% Helium and 2% of metals such as iron. Other characteristics are its rotation, temperature, and radiation.

Rotation

The Sun rotates on its axis, which is approximately the same axis that most of the planets revolved around the Sun. Since the Sun is primarily very hot gas, the surface at the equator rotates once every 25.4 days. The rotation near the poles is around 36 days. Also the surface swirls in high and low pressure areas, similar to those that occur on Earth.

The rotation of the Sun and the inclusion of iron in its core cause it to have a magnetic field, which is considerably more than the Earth's magnetic field.

Temperature

Its temperature is extremely hot, with the surface being about 5000° C and the center core at 15,600,000° C. The high temperature in the core, along with extreme pressure from the Sun's mass, result in nuclear fusion reactions. Two Hydrogen nuclei (protons) combine with two neutrons to form a Helium nucleus plus a release of energy.

Radiation

The energy released from the fusion reactions near the Sun's core is in the form of very high frequency electromagnetic waves called gamma rays.

As this radiation moves towards the Sun's surface, it is absorbed by atoms in the Sun's interior, increasing their kinetic energy. After absorption, the rays are then re-emitted at lower frequencies. This process continues until the radiation reaches the Sun's surface. By that time it is primarily visible light.

Surface effects

The surface of the Sun is called the photosphere. Some areas of the Sun's surface are hotter than the average 5000° C temperature and some are cooler. The cool areas look dark in comparison with the surrounding regions. They are called sunspots and are at about 3800° C.

The chromospheres lie above the photosphere. Above that is the corona which extends millions of kilometers into space and is visible only during a total solar eclipse.

Answer 28

characteristics of the sun ^^

Answer 29

this is as much as I know, I hope I helped
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Answer 30

Oh ok yeah its ok I'll reschedule my oral test for tomarrow.

Answer 31

i hope it all goes well!

Answer 32

Hope so to.

Answer 33

@nuttyliaczar Can u help me?

Answer 34

What's the question?

Answer 35

The distances in the universe.
HR diagrams.
The physical appearance of the sun.
How the electromagnetic spectrum is used to study stars and planets.

There all different things. I need to relearn.

Answer 36

It's been a while since I've used HR diagrams, and which distances do you want to know? Because you can probably look them up. The appearance of the sun is a vague question, but spectroscopy is used to identify elements within stars and planets. Each element has its own emission spectrum and so by looking at what wavelengths of light are emitted by the object, you can tell what it's made of. In the most basic terms

Answer 37

Yeah the distance one I dont really understand, I'll find out the HR diagrams and the distance but thanks for the help. Really appreciate it.

Answer 38

Basic thing to note about the HR diagrams: Higher up means the star is brighter and as a result generally more to the left since the brighter it burns the shorter the lifetime as it burns quicker. Study why some special stars are at the places they are on the diagram, like white dwarfs, giants, and supergiants

Answer 39

Oh ok, that makes more sense to me now.

Answer 40

I'll just figure out the what they mean about the distance in the galaxy. But thanks for the help.

Answer 41

Yeah sure. I have to sleep now but if you still need help tomorrow I'll be here, just shoot me a message

Answer 42

Ok thanks.