Astronomy 115 sfsu chris McCarthy midterm

Ecliptic Plane

The plane of Earth's orbit around the Sun/sun travels around the earth

Zenith

the highest point where you standing

Nadir

lowest point where standing

Direction of stars/planets

Sun, moon, and stars move west as Earth rotates East

Zodiac

A band of 13 constellations around the sky through which the Sun appears to move throughout the year.

Sun seasons

Caused by tilt of Earth, light hits it different in orbit with respect to ecliptic plane, is exposed to Earth longer or shorter

Autumnal Equinox

the equinox in autumn, on about September 22 in the northern hemisphere, day and night is exactly even

Vernal Equinox

the day of the year that marks the beginning of spring in the northern hemisphere, day is equal

Winter Solstice

December 1st, when the sun is at its lowest point

Summer Solstice

Day with the most hours of sunlight and the fewest hours of darkness, Sun highest in sky June 21st

moon phases

new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent

AU

Earth's distance from sun

Newton's Laws of Motion

INCLUDES 3 LAWS.

1. AN OBJECT AT REST WILL REMAIN AT REST UNLESS ACTED UPON BY AN (UNBALANCED) FORCE, AND AN OBJECT IN MOTION WILL CONTINUE TO STAY IN MOTION WITH THE SAME SPEED AND IN THE SAME DIRECTION UNLESS ACTED UPON BY AN (UNBALANCED) OUTSIDE FORCE. (THIS LAW IS ALSO CALLED "INERTIA")

2. ACCELERATION IS PRODUCED WHEN A FORCE ACTS ON MASS AND THE GREATER THE MASS OF THE OBJECT BEING ACCELERATED, THE GREATER THE AMOUNT OF FORCE NEEDED TO ACCELERATE THAT OBJECT.

3. FOR EVERY ACTION, THERE IS AN EQUAL AND OPPOSITE REACTION.

Diffraction

waves bending through small gap

Interference

When waves collide to become stronger or cancel out

electromagnetic spectrum

All of the frequencies or wavelengths of electromagnetic radiation

frequency formula

f=c/wavelength

Refraction telescope

a telescope that uses a converging lens to bend light.

Reflector telescope

A telescope that uses large mirrors to reflect and focus light.

Newtonian telescope

Has a primary and secondary mirror

Area of telescope

Larger, collects more light

Resolving power

See fine details in telescope, depends on diameter

magnifying power

Least important, enlargers image

Formula to determine telescope more powerful

D1/D2

Wavelengths that pass through atmosphere

Radio/visible light, some infrared/UV

Thermal Radiation

Electromagnetic radiation emitted from heat of material

Wien's Law

Longer the wave length, lower the temperature

Bohr Model

model of atom, electrons around nucleus like solar system

Spectrograph

Readout of spectrum of light, light intensity. Each element has a unique color spectrum

Continuum Spectrum

Rainbow fully present

Absorption Spectrum

some colors are missing (most stars)

Emissions spectrum

very few lines present

Doppler effect

Different in wavelength that we receive vs what is emitted

Sun's distance

120 mil kilometer, 1 AU, discovered thru the transit of venus

Sun's size

109 times larger than Earth

Sun's mass

333,000 times more massive than Earth

Sun's surface temp

5,800 Kelvin

Sun's composition

hydrogen (75%) and helium (25%) and plasma

Photosphere

Layer of sun we see, hottest layer, top convection zone

Chromosphere

The thin layer above the photosphere

Corona

outer most part of the sun, emits X-rays

Convection Zone (sun)

cells of hot gas bubble up then sink down in sun

Northern lights

Solar winds catch the corona, get brought right above Earth's atmosphere

Sun spots

As sun rotates, magnetic field becomes twisted, emerge as sun spots on surface, cooler parts, last for weeks.

Sun spot cycle

Every 11 years the North and South poles reverse, peak sun spots every time

Nuclear reactions in sun

Small hydrogen nuclei get together to form a larger Helium

Nuclear Fusion

combine small nuclei to make larger

Energy equation

E=mc^2

Parallax

Apparent shift of star compared to background due to Earth's rotation

Parallax equation

p=1/d