Exploring the Universe Test 1

What do telescopes do?

-Tool of science -Astronomers use it to track stars and research the night sky -Allow us to see fainter things and make things bigger

List the three layers of the suns atmosphere

1. Convection Zone: layer where energy moves to the suns surface 2. Radiation zone: layer where energy slowly moves upward 3. Core: where the energy is generated

What is the Speed of light?

300,000 km/sec

What is the sun mostly made of ?

71% hydrogen 27% helium 2% other elements by mass

Solar wind

A plasma stream emitted constantly by the sun.

Why is the time interval of sidereal/solar day different?

A solar day is about 4 mins longer than a sidereal day because while the earth rotated on its access it also moves along in its orbit around the sun.

Protostar

A star in its earliest observable phase of evolution ( A star being born )

What is the most important thing all scientists must know

Ambiguity, you can say "I don't know"

How do we use light to determine how fast an object is moving?

Based on blue shift/red shift

Why is the zodiac significant to the night sky?

Because ancient astronomers divided the zodiac into 12 different constellations

What fundamental truth did George Ellery Hale believe about the telescope?

Bigger the better

How do we analyze Magnetic fields on the Sun?

By using the Zeeman effect, a splitting or broadening of spectral lines of magnetic fields can be detected on the sun.

What causes the apparent daily motion of the sun in the sky?

Caused by the real revolution of the Earth around the sun.

Interferometer

Combines beams of light from two or more telescopes that combine light so we can combine a physical image.

What charecteristics are best for an astronomical observatory?

Dry Thin Steady On a mountain

Describe the different ways we monitor the sun

Ground based telescopes - visible light (optical) , radio telescopes, infrared telescopes Space based telescopes - ultraviolet, x-ray, gamma ray Spectoheliogaphs Coronagraphs (for examining the corona) ESA/NASA- SOHO spacecrafts US Solar Dynamics Observatory (spacecraft)

How else do we know what is occurring in the sun?

Helioseismology is the study of the suns internal structure by measuring global oscillations on its surface. we measure the suns surface by dopplers shift using 6 stations around the world

What effect does aperture have on a telescope?

How much light goes through the telescope by light gathering power.

Scientific Method

Idea, test, share (Pooh sticks)

How do we use neutrinos to determine what is going on inside the sun?

Neutrinos are natural elementary particles with no mass produced by fusion deep within the sun. By measuring their output we can "see" the fusion that occurs within the sun.

What are the atmospheric windows of observation?

Overall dynamic property of the earths atmosphere, takes as a whole at each place and occasion

Fusion

Process or result of joining 2 or more things together to form single entity

Main advantage of inferred astronomy

Reveals relatively cool objects that may not be visible

What types of stars evolve fastest?

Stars of similar chemistry with very high mass

Adaptive Optics

Stops twinkling of stars, makes the waviness go away

Sunspots

Temporary, dark relatively cool blotches on the photosphere

What do the numbers mean on the apparent magnitude scale?

The #'s on the scale mean 1 being the brightest through 6 the least bright

What is the ecliptic?

The apparent path of the sun against the background

What is the Zodiac?

The band about 16* wide around the sky that is centered on the ecliptic.

Why are bigger telescopes more desirable

The bigger they are the more you can see

What are the brightest and dimmest objects on the apparent magnitude scale?

The brightest night star.

What is a light year

The distance light travels through empty space in one year

Celestial Horizon

The great circle on the celestial sphere 90* from your zenith

Celestial Meridian

The great circle passing through your Zenith and the North and South points on your horizon

How do we use spectroscopy to determine the temp of an obj?

The hotter it is the more light it emits

What's apparent magnitude?

The magnitude of a celestial object as it is actually measured from the earth.

Zenith

The point on the celestial sphere directly over your head

Explain why the Earth has seasons.

The slant of the earth changes; some light pours down to earth from different angles during the year causing the changes of seasons as well seasonal variations in length of days and nights

Science?

The way to understand the law of nature. It is also about understanding how the universe works

What is the Electromagnetic spectrum?

The whole electromagnetic waves arranged according to wave length

Why do we place telescopes in orbit around the earth?

This is so we can get rid of the atmospheric interference

Cepheid Variables

Very large luminous yellow stars whose light output varies in periods from 1 to 70 days. They're important because they provide a way of measuring distance to great to be measured by trigonometric parallax.

What are two atmospheric window ranges which we may observe from the ground on Earth?

Visible light Radio

How can spectroscopy determine what something is made of

We look for Fraunhoffer lines and compare it because each element has diff. F lines

Radio-astronomy

When radio waves are redirected to a toned radio receiver that amplifies, detects and records their electronic image.

At what point does nuclear fusion begin in a protostar?

When the temperature in the YSO's center reaches 10million k

Orion Nebulla

a region of intense star formation, located 1,500 light years away in the constellation Orion.

Circumpolar Stars

a star viewed from a given latitude on earth

solar flares

a sudden, tremendous, explosive outburst of light, invisible radiation and material from the sun

Coronal mass ejection

an explosion of material off the sun

Visible Spectrum

arrangement of the colors according to the wave length

How is a photon like a particle and a wave at the same time?

because it will bounce off the same things or it will absorb

Why do high mass stars live shorter lives than low mass stars

because they use up their hydrogen most rapidly

Wave Length

distance from any point on a wave to the next identical point

Light Wave

electromagnetic disturbance consisting of rapidly varying electric and magnetic affects

What initial characteristics determines a star's life cycle?

its mass and chemical composition

Sidereal Day / Solar Day

measures the time interval of earths rotation using the stars for reference.

How did Hale think about what an observatory should be

place of science

What turns a star into a red giant or super giant

star expands surface temp drops, surface color turns red

What are circumpolar stars?

stars that are viewed from a given latitude on the earth

Stellar evolution

the change that takes place in stars as they age A.K.A. life Cycle of stars

What causes the apparent motion of the sun against the background of stars?

this results from earths real motion around the sun

Why is the concept of the celestial sphere useful to astronomers?

to locate stars and galaxies and to plot the courses of the moon and sun.