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Choose your side! Federation or Rebel Alliance?

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Presentation on theme: "Choose your side! Federation or Rebel Alliance?"— Presentation transcript:

1 Choose your side! Federation or Rebel Alliance?

2 Engage: Constellations
the pattern of stars seen in the sky, and refer to a specific region in the sky Roughly ____ constellations in all (same number as piano keys) Most are visible from North America at some time during the year 88

3 Cultures & Constellations
Different cultures grouped some of the same basic stars. Often varying interpretations Example: “The Big Dipper (North America) “The Wagon” or “The Plough” (Western Europe) Tail of the “The Great Bear” (Ancient Greeks) Leg of an Ox (Egyptians) “Stag” (Siberians) Is the “Big Dipper” a Constellation? Nope it is an asterism

4 Why do constellations move across the sky?
Why do Constellations seem to move across the sky from East to West? When can the Northern Hemisphere see the stars in the Southern Hemisphere? Apparent motion of the stars is the result the Earth’s rotation and revolution Through the year, the constellations shift gradually to the west. This is caused by Earth’s orbit around our Sun. In the summer, viewers are looking in a different direction in space at night than they are during the winter Never. The southern sky is below our horizon therefore out of our viewable sky

5 Zodiac Zodiac- Importance: How many (Remember video: “The Universe”):
a narrow band in the sky in which the movements of the major planets, Sun, and Moon take place, astrologically divided into twelve sections named for the major constellations. The annual cycle of the zodiac was used by ancient cultures to determine the time of year. There are 13 astronomical zodiac constellations: Capricornus, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, and Ophiuchus.

6 Light Pollution and Dark Sky Pollution
What is light pollution? What is the Dark Sky Association in relation to preserving dark skies for star viewing? is excessive, misdirected, or obtrusive artificial light is to preserve and protect the nighttime environment and our heritage of dark skies through environmentally responsible outdoor lighting.

7 EXPLORE: Stellar Parallax
is a displacement or difference in the apparent position of an object viewed along two different lines of sight Parallax: Stellar Parallax: is the effect of parallax on distant stars in astronomy. It is parallax on an interstellar scale, and it can be used to determine the distance of Earth to another star Astronomical Unit: Light Year: Parsec: Question: How do I explain that if I keep driving across the state the sun “appears” to follow me? distance from Earth to the Sun It is the distance that light can travel in one year parallax in arc seconds – 1” shift in in star = 206,265 AU= 1pc

8 Explore: Waves is a disturbance or oscillation that travels through space and matter, accompanied by a transfer of energy. Waves: Wave motion: transfers energy from one point to another, often with no permanent displacement of the particles of the medium They consist, instead, of oscillations or vibrations around almost fixed locations. Crest, Trough, Amplitude: shown above Wavelength: Frequency: Period: Speed = Distance distance between a crest and the adjacent crest, or a trough and the adjacent trough. which is the number of waves passing through a given point during the interval (related to wave speed) the amount of time required to complete one full cycle of the wave. Time

9 Explain: Medium What is a medium?
How do waves travel differently in different mediums? What is pitch? Speed = wavelength (λ) X is the matter a wave travels through, water, air, and steel because the atoms in different objects are packed differently causing the motion in solids to go quick and the motion in gases to go slow A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave. frequency

10 Movement of Waves Transverse: Compressional:
Sound Waves: Transverse or oscillations occurring perpendicular (or right angled) to the direction of energy transfer whose direction of vibration is the same as their direction of travel, aka longitudinal waves Compressional waves

11 Explain: EM Spectrum Name the different types of EM Waves
What are Electromagnetic Waves? Waves that carry energy and radiation. Name the different types of EM Waves Higher Frequency SHORTER wavelength Gamma X-ray UV VISIBLE (ROYGIV) MICROWAVE RADIO/TV FM "frequency modulation" AM stands for "amplitude modulation," Lower Frequency LONGER Wavelength

12 Explore/Explain: Brightness &Luminosity
Apparent Brightness: There are two factors that determine how bright a star appears: Luminosity: How does the Inverse Square Law relate to luminosity and apparent brightness? AB= 4d2 What is flux? The rate of transfer of energy over a given surface area is how bright a star appears is the of light it emits from its surface. actual amount its energy output per second (i.e. luminosity) distance. At a particular Luminosity, the more distant an object is, the fainter its apparent brightness becomes as the square of the distance. L determine the magnitude and spectral class of a star. It is the rate of transfer of energy across a given surface

13 Stars and Wavelength Because stars emit light with different wavelengths, they have different colors. Stars do not just emit one wavelength of electromagnetic radiation, but a range of wavelengths. If you look at the amount of light a star gives off at different wavelengths, you would get a graph like the one shown below The wavelength at which a star emits the most light is called the star's peak wavelength. The diagram below shows that this star has a peak wavelength of 4000 Angstroms.

14 Emission and Absorption Spectrum
The strong colored bands in the emission spectrum are shown as a compliment in the absorption spectrum as black lines The bolder and darker the black line in absorption the stronger the emission line colored wavelength in the emission spectrum Intensity Graphs reflect the strength of emission as peaks downward but higher on the graph on the y-axis when intensity of wavelength is greater

15 HR Diagram What is Wien’s Law and how does it help determine the temperature of stars? λmaxT=b What is a Cepheid star? Period of Cepheid star: Star Classifications: Stars are classified by their spectra (the elements that they absorb) and their temperature. There are seven main types of stars. In order of decreasing temperature. Observe the peak wavelength of the intensity spectrum then use the following equation Special stars that cycle from dim to bright in a regular pattern long periods are more luminous and have more power : O, B, A, F, G, K, and M

16 HR Diagram HR Diagram: is a scatter graph of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their spectral types or classifications and effective temperatures. Are not pictures or maps of the locations of the stars. they plot each star on a graph measuring the star's absolute magnitude or brightness against its temperature and color.

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