Stars, Planets And Moons

Question 0

What are the seven spectral classes?

Answer 0

O B A F G K M

Question 1

Why are stars divided into spectral classes?

Answer 1

To give an indication to a stars temperature and the chemical elements in a star

Question 2

Temp and colour of stars in the spectral class K? Eg.

Answer 2

3500 - 5000 K and orange eg. Aldebaran

Question 3

Temp and colour of stars in the spectral class M? Eg.

Answer 3

Less than 3,500 K and red-orange eg. Betelgeuse

Question 4

Temp and colour of stars in the spectral class G? Eg.

Answer 4

5,000 - 6,000 K and yellow eg. Sun, alpha Centauri

Question 5

Temp and colour of stars in the spectral class F? Eg.

Answer 5

6,000 - 7,500 K and yellow-white eg. Canopus and procyon

Question 6

Temp and colour of stars in the spectral class A? Eg.

Answer 6

7,500 - 10,000 K and white eg. Sirius

Question 7

Temp and colour of stars in the spectral class B? Eg.

Answer 7

10,000 - 30,000 K and blue-white eg. Rigel

Question 8

Temp and colour of stars in the spectral class O? Eg.

Answer 8

Greater than 30,000 K and blue-violet eg. Stars of Orion’s Belt

Question 9

What is a spectrum?

Answer 9

When white light is split by a prism. The light becomes spread out by wavelength and as a result you see the colours of the rainbow.

Question 10

What are absorption lines

Answer 10

Absorption lines are dark vertical lines through the spectrum which show which elements and molecules make up the star

Question 11

What is the narrow band from top left to bottom right on the HR diagram?

Answer 11

The main sequence stars

Question 12

What are main sequence stars?

Answer 12

When they fuse hydrogen to helium by nuclear fusion. Most stable part of a stars life cycle

Question 13

What is the band on the bottom left of the HR diagram?

Answer 13

White dwarf stars

Question 14

What are white dwarf stars?

Answer 14

Small, faint, hot very dense stars that are remnants of sun sized stars. Mostly made of carbon and area formed after red giant star loses it’s outer layers.
The remaining cores radiate leftover energy until none is left.

Question 15

What are the stars above and to the right of the main sequence stars?

Answer 15

Supergiants and giants

Question 16

What are supergiants and giant stars?

Answer 16

Older stars that have run out of hydrogen and now fuse heavier elements. These are the brightest stars in the sky

Question 17

What is he HR (Hertzsprung-Russell) diagram used for?

Answer 17

To plot a stars surface temperature and/or spectral class against its luminosity and/or absolute magnitude

Question 18

Stars with more mass are…

Answer 18

Hotter, brighter, bigger and bluer and live shorter because they use their fuel more quickly

Question 19

Stars with less mass are…

Answer 19

Cooler, dimmer, smaller and redder and live longer lives because they use their fuel slower

Question 20

How do stars look bright?

Answer 20

Being close, hot and big

Question 21

How do stars look dim?

Answer 21

Being far away, small and cool

Question 22

What is a star?

Answer 22

A giant luminous ball of very hot burning gas

Question 23

What is a planet?

Answer 23

An astronomical object moving in an elliptical orbit around a star

Question 24

What is a solar system?

Answer 24

A collection of planets and their moons, including smaller bodies I. The form of asteroids, meteoroids and comets in orbit around a star

Question 25

How many plants in our solar system?

Answer 25

8

Question 26

What are the planets in our solar system in order from the sun?

Answer 26

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune

Question 27

What are the planets in our solar system made of?

Answer 27

Hydrogen, helium, rocks, metals and minerals

Question 28

What holds stars together?

Answer 28

Gravity

Question 29

What reaction goes in inside a main sequence star?

Answer 29

Nuclear fusion - when the temperature is high enough the fusion of hydrogen to helium starts

Question 30

What is a moon?

Answer 30

A body that circles a lager planet or body

Question 31

What is a galaxy?

Answer 31

A system of billions of stars, including gas and dust, held together by gravitational attraction

Question 32

How fast does light travel?

Answer 32

300,000 kms-1

Question 33

Luminosity

Answer 33

Is the total amount of light a star gives off per second

Question 34

Brightness

Answer 34

What we see on earth

Question 35

What is magnitude?

Answer 35

A measure of brightness of stars

Question 36

What are the two types of magnitude?

Answer 36

Absolute magnitude and apparent magnitude

Question 37

Absolute magnitude

Answer 37

How bright the star actually is

Question 38

Apparent magnitude

Answer 38

Is how bright a star appears to us on earth

Question 39

How are stars born?

Answer 39

1. Giant gas and dust clouds (made up of mostly hydrogen) start to clump together by gravity. 2. This is often caused by energy waves from nearby exploding supernova. 3.The cloud collapses and begins to rotate and flatten into a disk. 4. Disk rotates faster and faster pulling more material inwards creating a hot dense core called a protostar 5. When protostar becomes hot enough, H atoms fuse producing He and energy 6. A bipolar flow erupts from the protostar and blasts away remaining gas and dust

Question 40

What are the two main sections of a star?

Answer 40

A very hot dense core (nuclear fusion) | An outer gaseous shell made of hydrogen and helium which moves heat from the core to the surface

Question 41

What is nuclear fusion?

Answer 41

When two or more atomic nuclei join or fuse to form a single heavier nucleus with the release of vast amounts of energy

Question 42

What are red dwarf stars?

Answer 42

Cool, dim, main sequence stars that fuse h to he slowly that they never evolve from main sequence into red giants

Question 43

What are black dwarfs?

Answer 43

A dead star - after white dwarfs lose their heat energy they become cold, dark black dwarfs

Question 44

What is a brown dwarf?

Answer 44

A dim, failed star- one whose mass is too small for nuclear fusion to start so it never becomes a main sequence star

Question 45

What is a neutron star?

Answer 45

Remnant of a supernova- very small and dense star composed mostly of tightly packed neutrons

Question 46

What is a pulsar star?

Answer 46

A rapidly spinning neutron star that emits energy in pulses

Question 47

What is hydrostatic equilibrium?

Answer 47

When a main sequence star has a balance between gravity - pulling atoms towards the centre of the star and the pressure of heat and light radiating out from the centre of the star

Question 48

What is the solar mass of the sun?

Answer 48

One solar mass 1Msun

Question 49

Why is knowing the mass of a star important?

Answer 49

Determines how bright a star is and how long the star will live

Question 50

What are the 3 main fuels stars fuse?

Answer 50

Hydrogen, helium and carbon

Question 51

What is luminosity measured compared with

Answer 51

Sun=1Lsun

Question 52

Measurement used for measuring distances around or solar system

Answer 52

Astronomical unit - 1AU = 150 million kilometres

Question 53

Measurement used to measure distance between stars

Answer 53

Light years - 1ly = 9.5 x 10^12 km or 63240 AU

Question 54

What are red giants

Answer 54

Form when sun sized stars run out of hydrogen

Question 55

What are supergiants

Answer 55

Form when massive stars run out of hydrogen eventually become supernovae

Question 56

What are blue giants/supergiants

Answer 56

Massive blue stars close to running out or have just run out of hydrogen eventually become supernovae