Telescopes

Question 1

3 types of telescopes

Answer 1

1. Refracting
2. Reflecting
3. Multi-wavelength

Question 2

Refracting telescopes

Answer 2

• uses 2 lenses, concave and convex
• problems include low resolution, opening was too small which created fuzzy images, and different types of diffraction patterns are produced.

Question 3

Reflecting telescopes

Answer 3

• uses a curved mirror that focuses using reflection
• advantages include large opening and less diffraction, mirror can be supported from underneath which maintains its shape, used to gather visible light, IR, and UV radiation, and it contains 2 mirrors and a lens that focuses the light into the observers eye

Question 4

Multi-wavelength telescopes

Answer 4

• advanced reflecting telescopes that are at high altitudes or orbiting the earth
• gathers as many types of EMR as possible, differences in telescopes based on type of radiation absorbed
• radio waves = huge dish produces lots of diffraction- use many radio telescopes to collect data

Question 5

Analyzing starlight

Answer 5

• objects at 6000 degrees emit mostly visible light, this creates a rainbow or colours called the continuous spectrum

Question 6

Absorption spectrum/Dark line spectrum

Answer 6

• beyond the sun, the spectrum is not continuous but has dark lines where radiation has been absorbed, this is known as the dark line or absorption spectrum
• occurs when EMR passes through a cool source
• The more dark lines the colder the star
• The dark lines identify the material or gases in the star

Question 7

Bright line spectrum

Answer 7

• when current is forced through a low pressure gas, the gas emits wavelengths and we see emissions of a bright line spectrum
• spectra are analyzed using a spectra scope; a diffraction grating attached to a device that calculates wavelength
• occurs when EMR passes through a hot gas

Question 8

Doppler shift

Answer 8

• the shift in frequency of a wave due to the relative motion between the observer and the source
• towards the source = higher frequency of sound
• away from source = lower frequency

Question 9

Blue shift

Answer 9

Higher frequencies and shorter wavelength, moves towards

Question 10

Red shift

Answer 10

Lower frequencies and longer wavelength, moves away from