Astronomy 2 (not deleted)

Frequency

How many times something happens in a second. High frquency = low energy. low frequency = less energy

Wavelength

longer wavelength = less energy

shorter wavelength = high energy

How long each wave is

Energy

The capacity to do work or produce change, often related to the amplitude of a wave. Higher energy corresponds to shorter wavelengths and higher frequencies.

Light with a higher frequency has a (higher/lower) energy and a (longer/shorter) wavelength.

Light with a higher frequency has a higher energy and a shorter wavelength.

Light with a shorter wavelength has a (higher/lower) frequency and a (higher/lower) energy.

Light with a shorter wavelength has a higher frequency and a higher energy.

Which (color/frequency/wavelength) of light is often used to warm food?

infared light

Which (color/frequency/wavelength) of light is often used to communicate over long distances?

The wavelength of light is often used to communicate over long distances—especially in the form of infrared or laser light in fiber optic communication systems.

Which (color/frequency/wavelength) of light is often used to photograph bones in the body?

The frequency of light is often used to photograph bones in the body—specifically, high-frequency electromagnetic waves known as X-rays.

Which has a longer wavelength red or green?

red

Which has a longer wavelength, blue or radio?

radio

Which has a longer wavelength orange or x-ray?

orange

Which has a greater frequency red or purple?

Purple

Which has a greater frequency gamma or microwave?

Gamma

Which has a greater frequency yellow or ultra-violet?

Ultra-violet

Which has a greater energy x-ray or green?

X-rays have greater energy than green light due to their shorter wavelength and higher frequency in the electromagnetic spectrum.

Which has a greater energy blue or red?

blue

Which has a greater energy ultraviolet or radio?

ultraviolet

Why are astronomers interested in putting telescopes in space?

To see things outside the eath without protection from the atmosphere. This will allow us to see gamma, UV, and X-Rays. Can get us sharper images

Are radio waves from the sun or stars absorbed by clouds?

No, radio waves from the Sun or stars are not significantly absorbed by clouds.

When an object is heated, list the colors that it will glow (in order from coolest to hottest)

Red, Orange, Yellow, White, Blue

Because light travels in waves, the light coming from an object moving towards the Earth will be shifted to the ________ end of the spectrum and an object moving away from the  Earth will have  _________ shifted colors. 

 

Blueshift, redshift

What is the speed of light?

3×10^5 km/s

When atoms of an element are excited (with heat, light or electricity) they emit specific colors of light.  What is the name for this type of spectrum?

Emission spectrum

When light shines through a chemical (combination of elements) some light of specific colors is missing, What is the name for this type of spectrum?

Absorption spectrum

Which is the most useful spectrum for studying stars?

Absorption spectrum is used to study the stars

Which type of lens causes light rays to converge / diverge?    (concave/convex)

A curved mirror causes light rays to converge and diverge

Which type of mirror causes light rays to converge / diverge?

a curved mirror

If an incoming incident beam of light hits a specular mirror at 36 degree angle, what angle will the reflected beam leave the mirror?

36 degrees

What are the 6 basic physical changes?

Melting, Freezing, vaporization, condensation, sublimation, and deposition

What type of change (or reaction) involves sharing or transfer of electrons between atoms?

A chemical change or chemical reaction

What 3 basic sub-atomic particles? 

Proton, Neutron, and electron

What is the electrical charge of each?

Proton has a positive charge

Neutron has no charge

Electron has negative charge

Where within the atom is each particle located?

Protons and Neutrons are in the nucleus. Electrons are located in the outside of the nucleus in energy levels or shells

Elements are the basic building blocks of all matter… How many naturally occurring elements exist?

92

List several examples of chemical reactions (chemical changes)

 

Rusting, Burning, Digestion

What is the difference between an Isotope and an Ion?

An isotope is the same element with different number of neutrons which cause different masses. An ion is an atom that has gained or lost electrons

What type of nuclear reaction involves splitting of heavy atomic nuclei?                            Example?

Fission. An example is Uranium-235

What type of nuclear reaction involves combining of atomic nuclei?                                   Example?

Nuclear Fusion. An example is the fusion of hydrogen isotopes to form helium

Of the three types of reactions (Physical, Chemical, Nuclear) which involves the loss of mass and the creation of energy?

Nuclear reactions

What famous equation describes that process?                                    What does each term represent?

 

E=mc². E represents energy released in joules, m represents mass in kg, and c represents the speed of light.

Sub-critical mass

Mass that isn’t stable enough to sustain a chain reaction.

Critical mass

The amount of mass required to sustain a chain reaction

Super critical mass

Amount of material that is larger than the critical mass

Where was the first fission experiment conducted?                   In the history of the earth was this a first?

The manhattan project

In a nuclear reactor, how is the level of critical reaction maintained?

 

Control rods, a moderator, Fuel composition, and a coolant.

In nuclear fusion, what is the most common element used and what products are produced?

Hydrogen. Neutrons, Helium, and Energy are produced

What temperatures are necessary for this type of nuclear fusion?

 

100 million degrees celsius/180 million degrees fahrenheit

What process was first used to generate the extreme temperatures necessary to start fusion?

Nuclear fusion

What other forms of energy are scientists using to attempt nuclear fusion?

 

Laser-Based Fusion

Microwave Heating

Neutral Beam Injection

What is the energy source for the sun?  (Why does the sun give off energy?)

hydrogen fusion which is hydrogen to turn into helium for energy

Why doesn’t the sun blow up?  (explain)

It is already blowing up. if the sun stops blowing up, that is scary. Energy crushed the explosion causing it to only happen on the sun called Hydrostatic equilibrium

What is the approximate age of the sun?

4.6 billions years old

Where in the sun do the nuclear reactions occur?

 

The core

Where on the sun could you find a sun spot?

on its visible surface (the photosphere)

Why are sun spots darker than the surrounding area?

the sunspots are cooler then the surface causing it to not shine as bright

What is the duration (length) of the sun spot cycle and at what point in the cycle is the current state of the sun?

11 years

Explain the difference between apparent and absolute magnitude?

Apparent magnitude is how bright a star appears from the Earth. Absolute Magnitude is how bright a star actually is in parsecs.

Explain the brightness difference between a magnitude 2 and magnitude 7 star.

Magnitude 2 star is much brighter then a mgnitude 7 star

If a red giant star appears 1/100^th as bright as the red giant Aldebaran, how much greater is the distance to that star?

10 x

Brightness is proportional to temperature and size, which has the greater effect on the brightness of a star?

Temperature

What is the difference between Actual and Apparent Stellar motion?

Actual Stellar motion is the true motion of a star throughout space. Apparent stellar motion is how a star position changes from the naked eye on Earth

Give two examples (explain the cause) of apparent stellar motion.

The seasons and the rotation of the earth.

Which star has virtually no apparent motion?                    Why?

The North Star because it is directly above the North Pole so it is fixed in the jight sky while at the point of the Earths rotational axis

Explain the three ways for detecting a binary star.

Visual detection, through light shifts, and from eclipsing

What is the size range for stars?   (Diameter and Mass)

Diameter could be from 20 kilometers to 1,000 times the sun’s diameter. Mass could be from .08 solar masses to 150-300 solar masses

What type of spectrum is most useful for identifying the chemical make up of stars?

Absorption spectrum. It shows the dark lines where light has been absorbed to see what elements are in the stars atmosphere

Which astronomer developed the current 7 category classification system for stars?   What property is this based upon?

Annye Jump Cannon. The classification is based on the surface temperature of stars

Often considered the most important graph in Astronomy, explain the H-R diagram

The HR diagram is a chart that plots the stars by luminosity(brightness) and surface temperature (spectral class.

Reading this diagram, most blue stars are ___________________ and red stars are________________

hotter and more luminous, cooler and less luminous

What is the name given to the S shaped curve along which most stars are located on this graph?

Main sequence

What are two ways that we can determine the age of stars?

HR diagram and through stellar composition

What is the name given to the large gas cloud from which stars are formed?

Nebula

What gas must be present for star formation?

Hydrogen

This term is used to describe a hot, star forming region of the gas cloud before a star is born.

Protostar

What forces is acting on the gas cloud?

Gravity

What term is used to describe star like objects that are too small to sustain nuclear fusion?

Brown Dwarfs

At what temperature will Hydrogen fusion begin?

10 millions kelvin

If nebula creates a small star cluster with 5 Sun sized stars, approximately how many small red M class stars will be formed?

Around 500 or more

How does a star maintain a stable size?

Hydrostatic equilibrium. Gravity and pressure move in opposite directions cancelling each other out

How long will a main sequence star last?

10 billions years

Explain the two changes that happen when a star becomes a Red Giant?

The core contracts and heats up while the surface enlarges and starts to cool

What is the term that describes the atmosphere blown away from a star after fusion stops?

Planetary Nebula

Explain why this expanding cloud of gas shines.

It is illuminated by the glowing core which excites the surrounding gas causing it to glow

What is the approximate size, composition , and temperature of a white dwarf?

White dwarf is about the size of earth. it is made up of mostly carbon and oxygen. Its temperature starts around 100,000 K but cools over the years

Will it be possible for the sun to become a Nova?          (why/why not- describe the process)

No it won’t. For the sun to become a nova there it needs to be in a binary star system, meaning two stars. Our solar system has 1 star and does not meet the conditions to become a Nova

Why do large stars have a shorter life than an average main sequence star?

Large stars how more mass so they burn through their fuel much faster due to higher core temperatures and pressures.

After a Red Super Giant completes He to C fusion, what elements may fuse when the temperature reaches 6X10⁸ to 2.7X10⁹K ?

Oxygen (O), Neon (Ne), Magnesium (Mg), and Silicon (Si)

When a star begins Iron fusion, what force that balances a normal star stops?

pressure from fusion

After the fusion stops and the star core collapses, this is the term used to describe the violent outward explosion that may be as bright as 1X10⁹ stars.

Supernova

Briefly describe the difference between a type II and type Ia Supernova

Type II Supernova is caused by the core collapse of a massive star after iron is built up in the core. Type 1a supernova occurs in a binary star system. This is when a white dwarf collects matter from a companion star until it reaches critical mass causing a thermonuclear explosion

Describe the process that forms the neutron star?

The core of the star collapses after the supernova. The protons and electrons combine into neutrons which form an extremely dense, compact star made of mostly neutrons

What is the approximate size of a neutron star?

10 - 20 kilometers in diameter

If a rotating neutron star has a beam of radio waves that sweeps across space, it will be called a ____________

Pulsar

After a supernova for a star with a core mass greater than 2 times the mass of the sun, the stellar leftover will not be a neutron star, it will be a ______________

Black hole

List three of the basic properties of a black hole:

Mass, electrical charge, and spin

What is the approximate Swartzchild radius of a 10 M_Sun black hole?

about 29.5 kilometers

What is the term used to describe a sparse grouping of up to a 1000 stars that are bound together by gravity?

Star cluster

Located around the halo of some galaxies, these star clusters may have 100,000 or 1,000,000 stars.

Globular clusters

How would our view of the night sky change if the Sun’s position was closer to the center of the Milky Way?

It would be much brighter due to the densely packed stars and dust clouds.

While several early astronomers tried to map our position in the Milky Way based off positions of the stars, Harlo Shapley achieved a more accurate result by mapping locations of these objects.

He used globular clusters to estimate the size and shape of the Milky way, and to determine how far we were from the center