Astronomy Chapter 1

Front 1

North star

Back 1

Polaris

Front 2

Scientific notation

Back 2

System of recording very large or very small numbers by using powers of ten

Front 3

Planet

Back 3

Large enough to be spherical and has cleared it's own orbital payh

Front 4

Solar system

Back 4

Sun planets asteroids comets etc

Front 5

Star

Back 5

Globe of gas held by its own gravity and is held together by gravity and supported by the heat of its own internal pressure of hot gasses

Front 6

Distance of the earth to the moon is

Back 6

380,000 km or 240,000 m

Front 7

Sun is how much larger in diameter than earth

Back 7

110

Front 8

Earth or its the sun ___ times a year

Back 8

One

Front 9

Astronomical unit

Back 9

Au: measure even larger distances than scientific notation

Front 10

Light year

Back 10

Distance that light travels in a year which is 63,000 au or 10 to the 13 km

Front 11

Galaxy

Back 11

Large system of stars, star clusters, gas and dust

Front 12

Milky way

Back 12

Hazy band if light that circles our sky and is produced by the glow of our galaxy

Front 13

Spiral arms

Back 13

Long spiral pattern of bright stars, star clusters, gas dust and extend across the disks of spiral galaxies

Front 14

Super cluster

Back 14

A cluster of galaxy clusters

Front 15

Constellation

Back 15

One of the stellar patterns identified by name usually of mythological fods, people, animals or objects. Also region of the sky containing that star pattern

Front 16

Asterism

Back 16

A named grouping of stars that is not one of the rego mixed constellations

Front 17

Magnitude scale

Back 17

The astronomical brightness scale. The larger the number the fainter the star

Front 18

Apparent visual magnitude

Back 18

A measure of the brightness of a star as seen by human eyes on earth

Front 19

Flux

Back 19

Measure of the flow of energy through a surface. Usually applied to light

Front 20

Celestial sphere

Back 20

An imaginary sphere of very large radius surrounding earth to which planets stars sun and moon seem to be attached

Front 21

Precession

Back 21

Slow change in orientation of earths axis of rotation. One cycle takes 26,000 years.

Front 22

Rotation

Back 22

Motion around an axis passing through the rotating body

Front 23

Revolution

Back 23

Orbital motion about a point located outside orbiting body

Front 24

Ecpliptic

Back 24

Apparent path of the sun around the sky

Front 25

Zodiax

Back 25

Band centered on the ecliptic and encircling the sky

Front 26

Evening star

Back 26

Any planet visible in the sky adter the sunsets.

Front 27

Morning star

Back 27

Any planet visible in the sky befoee sunrise

Front 28

Solar eclipse

Back 28

Event that occurs when the moon passes directly between earth and the sun blocking your view of the sun

Front 29

Umbra

Back 29

Region of shadow that is totally shaded

Front 30

Penumbra

Back 30

Portion of a shadow only partially shaded

Front 31

Annular eclipse

Back 31

A solar eclipse in which the solar photos here appears around the edge of the moon in a bright ring or annulus. Features of the solar atmosphere can't be seen during annular eclipse.

Front 32

Lunar eclipae

Back 32

The darkening of the moon when it moves through earths shadow

Front 33

Saeos cycle

Back 33

18 year 11 and 1\3 day period after which the pattern of lunar and solar eclipses repeats

Front 34

First principle

Back 34

Something that seems obviously true and needs no further examination

Front 35

Geocentric universe

Back 35

Model universe with earth at the center such as polemic universe

Front 36

Hello centric universe

Back 36

Model of the universe with the sun at the center such as the copernican universe

Front 37

Paradigm

Back 37

Commonly accepted set of scientific ideas and assumptions

Front 38

Ellipse

Back 38

Closed curve around two points called foci such that the total distance from one focus to the curve and back to other focus remains constant

Front 39

Eccentricity

Back 39

Number between 1 and 0 that describes the shape of an ellipse. Distance from one focus to the focus of the ellipse divided by the semi major axis

Front 40

Semi major axis

Back 40

Half of the longest diameter of ellipse.

Front 41

Empirical

Back 41

Description of a phenomenon without explaining why it occurs

Front 42

Hypothesis

Back 42

Conjecture, subject to further test the accounts for a set of facts

Front 43

Theory

Back 43

System of assumptions and principles applicable to a wide range of phenomena that has been repeatedly verifoed

Front 44

Natural law

Back 44

Theory that has been so well confirmed it is almost universally accepted as correct

Front 45

Mass

Back 45

Measure of the amount of matter making up an object

Front 46

Weight

Back 46

The force that gravity exerts on an object

Front 47

Inverse square relation

Back 47

Rule that the strength of an effect decreases in proportion as the distance squared increases

Front 48

Spring tide

Back 48

Ocean tide of large range that occurs at full and new moon. Refers to leaping not the season

Front 49

Neap tide

Back 49

Ocean tide of small range occurring at first and third quarter moon

Front 50

Electromagnetic radiation

Back 50

Changing electric and magnetic fields that travel through space and transfer energy from one place to another. Ie light and radio waves

Front 51

Wavelength

Back 51

The distance between successive peaks or troughs of a wave

Front 52

Nanometer

Back 52

Unit equaling one billionth of a meter. Used to measure wavelength of light

Front 53

Angstrom

Back 53

Unit if distance commonly used to measure wavelength of light

Front 54

Infared

Back 54

Portion if electromagnetic spectrum with wavelength longer than red light

Front 55

Ultraviolet

Back 55

Portion of electromagnetic spectrum with wavelength shorter than violet light between visible light and x rays

Front 56

X ray

Back 56

Electromagnetic waves with wavelengths shorter than ultraviolet light

Front 57

Gamma rays

Back 57

Shortest wavelength of electromagnetic waves

Front 58

Photon

Back 58

Quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength

Front 59

Atmospheric window

Back 59

Wavelength region in which our atmosphere is transparent at visual radio and some infared wavelength

Front 60

Refraction telescope

Back 60

Forms images that bend light with a lens

Front 61

Reflecting telescope

Back 61

Telescope that forms images by reflecting light with a mirror

Front 62

Primary lens

Back 62

In refracting telescope it is the largest lens

Front 63

Primary mirror

Back 63

In a reflecting telescope the largest mirror

Front 64

Focal length

Back 64

The length of a lens or mirror is the distance from that lens or mirror to the point of where if focuses parallel rays of light

Front 65

Chromatic aberration

Back 65

Distortion found in refracting telescopes because lenses focus different colors at slightly different distances

Front 66

Optical telescope

Back 66

Telescope that gathers visible light

Front 67

Radio telescppe

Back 67

Telescope that gathers radio radiatoon

Front 68

Light gathering oower

Back 68

Ability of telescope to collect light

Front 69

Resolving power

Back 69

Ability of a telescope to reveal fine detail

Front 70

Diffraction fringe

Back 70

Blurred image surrounding any image, caused by wave properties of light

Front 71

Interferometer

Back 71

Separated telescopes combined to produce a virtual telescppe with the resolution of a much larger diameter telescope

Front 72

Seeing

Back 72

Atmospheric conditions on a given night. When atmosphere is unsteady, producing blurred images seeing is poor

Front 73

Adaptive optics

Back 73

Computer controlled optical system in an astronomical telescope used to partially correct for seeing

Front 74

Magnifying power

Back 74

Ability of a telescope to make an image larger

Front 75

Sidereal tracking

Back 75

Continuous movement of a telescope to keep at a star as earth rotates

Front 76

Photographic plate

Back 76

First image recording device used with telescopes. Records the brightness of objects but with only moderate precision

Front 77

Photometer

Back 77

Sensitive astronomical unit that measures of individual objects very precisely

Front 78

Charge coupled device

Back 78

Electronic device that consists of a large array of light sensitive elements used to record very faint images

Front 79

Array detector

Back 79

Device for collecting and recording electromagnetic radiation using multiple individual detector arrayed on the surface of a chil

Front 80

Digitized

Back 80

Converted numerical data that can be read directly into a computer memory for later studying

Front 81

False color image

Back 81

Representation of data with added or enhanced color to reveal detail

Front 82

Specrrograph

Back 82

Device that separates light by wavelengths to produce spectrum

Front 83

Spectrum

Back 83

Range of electromagnetic radiation spread into its component wavelengths.

Front 84

Grating

Back 84

Piece of material in which numerous microscopic parallel lines are scribed. Light that encounters a grating is dispersed to form spectrum

Front 85

Quasad

Back 85

Small powerful source of energy in the active core of a very distant galaxy

Front 86

Diameter of earth

Back 86

12800 or 8000 miles

Front 87

Visible disk of our glalaxy

Back 87

80,000 light years in diameter