Astronomy Assignment 5

Front 1

What is the light gathering power of an 8 inch telescope compared to a 4 inch telescope?

Back 1

4 time better

Front 2

If the rest wavelength of a certain line is 600 nm, but we observe it at 588 nm, then:

Back 2

The object is approaching you at 2% the speed of light

Front 3

Which type of telescope has the simplest light path?

Back 3

Prime focus reflector

Front 4

all modern large optical telescopes are refractors

Back 4

False (they are reflectors)

Front 5

Green light has a shorter wavelength than orange light. In a 5 inch telescope, green light will:

Back 5

provide better angular resolution than orange light

Front 6

One advantage of the Hubble Space telescope over ground based ones is that:

Back 6

In orbit, it can operate close to its diffraction limit at visible wavelengths

Front 7

Optical telescopes are usually used only at night, but radio telescope can be used day or night.

Back 7

True

Front 8

Which of the following is a reason to use a reflecting telescopee rather than a refractor?

Back 8

Lenses absorb light, while mirrors do not.

A lens must have two precision surfaces, a mirror only needs one.

Keavy lenses, which can only be supported at their edges, tend to deform under their own weight.

Lenses are subject to chromatic aberration.

Front 9

The amount of diffraction and thus the resolution of the telescope depends upon:

Back 9

the wavelength used and the size of the main telescope objective lens or mirror.

Front 10

In the Doppler effect, a red shift of spectral lines shows us the soruce is receding from us:

Back 10

True

Front 11

What is true of radio telescopes?

Back 11

They have poorer angular resolution than a refractor of the same size

Front 12

Galaxies look the same whether viewed in visible or X-ray wavelengths

Back 12

False

Front 13

A telescope design that uses a lens and no mirrors is a refractor

Back 13

True

Front 14

_________ optics greatly reduce the effect of atmospheric turbulence by deforming the shape of the mirror by computer control:

Back 14

Adaptive

Front 15

In the future, adaptive optics will greatly enhance the resolution of the hubble space telescope.

Back 15

False

Front 16

If a source of light is approaching us at 30,000 km/sec, then all of its waves are:

Back 16

Blue shifted by 10%

Front 17

Compared to a 5 inch prime focus reflector, a 5 inch Newtonian reflector will:

Back 17

Have the same light gathering power

Front 18

Stars do not twinkly, the instability of the atmosphere causes this:

Back 18

True

Front 19

The ability of a telescope to seperate two closely spaced stars is called:

Back 19

Resolution

Front 20

The primary purpose of a telescope is to

Back 20

Collect a large amount of light and bring it into focus

Front 21

In astronomy, an interferometer can be used to:

Back 21

improve the angular resolution of radio telescopes

Front 22

All optical telescopes will bring the light from a star to a focus:

Back 22

True

Front 23

The observed spectral lines of a star are all shifted towards teh red end of the spectrum.

Back 23

This is an example of the Doppler Effect

Front 24

Grazing incidence optics are critical to focusing

Back 24

X-ray radiation

Front 25

The angular resolution of an 8 inch telescope is _________ greater than that of a 2 inch diameter telescope:

Back 25

4 times more

Front 26

The light gathering ability of a telescope is most dependent on the diameter of its primary mirror/lens

Back 26

True