astronomy

ASTRONOMYStudy of heavenly bodies

AstronomyStudy of heavenly bodies

MEASURING THE UNIVERSEAstronomical Unit – Earth’s distance from the sunLight Year – distance that light year travels

GALAXYGalaxy – group of billion of stars that

moves through

spaces as a unit

TYPES OF GALAXY1. Spiral Galaxy - has a circular bulge at the center and arms, which indicates it’s spin.

SPIRAL GALAXY

TYPES OF GALAXY2. Barred Spiral Galaxy - the central bulge is longer than it is wide

BARRED SPIRAL GALAXY

TYPES OF GALAXY3. Elliptical Galaxy

- Oval in shape- reported to contain mostly

older stars

ELLIPTICAL GALAXY

TYPES OF GALAXY3. Irregular Galaxy

- no definite shape, appears to be a hazy cloud

- contains interstellar material and young star

- believe that eventually absorbed by larger galaxies when they collide

IRREGULAR GALAXY

Star - a luminous body in the skyMagnitude – apparent brightness of a star, describe by a number (1- 6 )

Nova – an exploding star

1. Distance – brightness diminishes with increasing distance

Factors Affecting Magnitude:

2. Size – the bigger, the brighter a. Super Giant b. Giant c. Dwarf

3. Temperaturea. White/Blue white – 30,000-60,000 Fb. Red – 3,000 – 6,000 Fc. Yellow – 10,000 Fd. Orange – 6,000 – 8,000 F

Permanent scattering of the star

Constellation

Pegasus the winged horse

Constellation Cassiopeia

Constellation Cygnus

Constellation Perseus

composed of the sun and the planets

Solar System

The Sun is the center of the Solar

System

Inner Planets

Mercury

Inner Planets

Asteroid Belt – lies between the orbit of Mars and Jupiter

Outer Planets

Jupiter

Outer Planets

Saturn

Outer Planets

Uranus

Outer Planets

Neptune

THEORIES1. Planetesimal Theory

- states that large masses of matter where thrown out of the sun when it experienced a glancing collision with another star, the materials cooled formed small bodies which eventually joined and formed the planets

- proposed by Comte de Buffon, a French scientist

THEORIES2. Binary Star Theory

- suggest that the sun once had a companion star which exploded several billion years ago

- proposed by Fred Hoyle, a modern British astronomer

THEORIES3. Cloud Dust Theory

- the solar system began as a vast saucer-shaped hot cloud of gas and dust slowly revolving in space, the cloud cooled and shrank, it began to spin faster, causing ring of matter to break away from the outer edge. Each ring gave rise to a star and the central mass became the sun.

- proposed by Laplace in 1796

SUN- A ball of incandescent light

CHARACTERISTICS OF THE SUNIt’s a huge ball of flaming gasesa. Hydrogen – 71%b. Helium – 27.1%c. Other gases – 1.9% (Oxygen, Carbon, Nitrogen, Neon, Magnesium, Iron, Sulfur, Sodium)

CHARACTERISTICS OF THE SUNHas a diameter of 1,393,000 KmIt has a mass of 1.99 x 1030KgTemperature:

Core – 15,000,000 KSurface – 6,000K

Rotates on it’s axis every 24.65 earth days at it’s equator and every 35 earth days near it’s pole

CHARACTERISTICS OF THE SUNCompared to other stars, the sun is medium sized, of average brightness and middle age

REGIONCoreRadiation ZoneConvection ZonePhotosphere Chromospheres Corona

CORE- has a diameter of about 400,000 Km.- generates a tremendous amount of energy from nuclear reactions- temperature is about 15,000,000 K,decreasing outward to the surface.

Radiation Zone- is about 300,000

Km thick and located above the core- transport solar energy toward the surface by electromagnetic radiation

Convection Zone- about 200,000

Km thick- located above the radiation zone- transport energy toward the surface by convection movement of the sun’s material

Photosphere- sun’s visible surface- located above the convection zone- estimated to be 500 to 800 Km thick- temperature is 5780 K

Chromosphere- sun’s lower

atmosphere- extending outward from 10,000 to 19,000 Km above the photosphere- made up primarily of hydrogen

Chromosphere

ENERGY OF THE SUNAstronomy

Study of heavenly bodies

During the nuclear fusion reaction, some matter is actually converted in a way Einstein explained by his famous equation.

E=mc2E is the energy produced from the

matter, m is the mass of the matter that has been converted into energy, and c2 is the square of the speed of light.

DISTURBANCES OF THE SUN

DISTURBANCES OF THE SUN1. Sunspot

- dark spot on the surface of the sun- are areas of gas that are relatively

cooler than the rest of the sun’s surface- they are almost 2,000 K cooler than

their surroundings- usually 10,000 Km across- varies over an 11 year period

DISTURBANCES OF THE SUN2. Solar Prominences

- are streams of very hot glowing gas rising high into the outer layer of the solar atmosphere and clearly visible at the edge of the sun against the darkness of space behind them

- extends about 100,000 Km above the sun’s surface

DISTURBANCES OF THE SUN3. Solar Flares

- giant jet of gas that shoot up thousands of kilometres from the sun’s surface

- temporary outbursts of energy from a small area of the sun’s surface

- occur lower in the sun’s atmosphere- violent than prominences, causing

radio and other electromagnetic radiation as well as particles

DISTURBANCES OF THE SUN3. Solar Flares

Result to the brilliant displays of the auroras, the northern and southern lights, occur in the region around the north and south poles

AURORA BOREALIS

AURORA AUSTRALIS

- Has a diameter of 3476 Km.- It’s mass is 7.35 x 1022 kg- Has an average density of 3.3 g/cm3

also known as Luna

is a natural satellite in orbit around a planet

CHARACTERISTICS OF THE MOON

It’s distance from the earth varies from 363,000 Km (at Perigee) to 406,000 km (at Apogee)

Its gravity is only 1/6 that of the earth which has effect on the weight of objects on it’s surface

- The temperature can reach extremes, from high as 100 C to as low as -100 C- Rotates on it’s axis once every 27 days, 7h, 43min, 11s (27.322 days)

It does not shine with it’s own light but only reflects the light from the sun

PHASES OF THE MOON

Refers to the different shapes of the lighted portion

The orbiting of the moon around Earth from and back to the new moon phases makes one Lunar cycle.

PHASES OF THE MOON1. New Moon

- when it is completely invisible in the night sky because we are facing the dark side of the moon.

PHASES OF THE MOON2. Waxing Crescent

- lighted portion is seen as inverted C shape

PHASES OF THE MOON3. First Quarter

- ¼ of the moon is lighted and seen as D

PHASES OF THE MOON4. Waxing Gibbous

- ¾ of the moon is lighted and seen

PHASES OF THE MOON5. Full Moon

- half of the moon is lighted and we are facing the lighted side

PHASES OF THE MOON6. Waning Gibbous

- the lighted portion is decreasing

PHASES OF THE MOON7. Last Quarter

- one fourth of the moon is lighted

PHASES OF THE MOON8. Waning Crescent

- lighted portion is seen as C shape

ECLIPSEThe shading or darkening of one

heavenly body by another

Only happens when the sun, the moon and the earth form a straight line with one another but not every new moon and full moon because the planes of the moon’s orbit is lightly tilted by a little over five degrees from the plane of the earth’s orbit.

TYPES OF ECLIPSE

TYPES OF ECLIPSEAstronomy

1. Solar Eclipse

- eclipse of the sun- the moon is between the sun and the

earth- the shadow of the moon falls on

earth, thereby covering the sun- last for 2-3 minutes only, the longest

is 7.5 minutes

TYPES OF ECLIPSEAstronomy

2. Lunar Eclipse

- eclipse of the moon- earth is between the sun and the

moon- the moon can not be seen from the

earth- last for as long as 3 hrs and 40 min- earth’s shadow extends to around

1,383,740 Km

TWO PARTS OF THE SHADOW

- light outer area- people located in the penumbra witness only a partial eclipse of the sun, that is, the sun is only partly hidden

PENUMBRA

- darker inner area- people located in the umbra of the moon’s shadow witness a total eclipse of the sun, that is, the sun is completely hidden from view

Refers to rise and fall of water level in sea caused by gravitational pull of the moon and the sun on the spinning, or rotating,

High Tide happens when the three bodies form a straight line.

TIDES Low Tide occurs when the three bodies (sun, earth and the moon) are at the right angle.

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