Chapter 3: Question 31
What problem do refractor telescopes have that reflectors don't?
A. Chromatic Aberration
Chromatic Aberration: when light is separated into its component colors
Diffraction Limited Resolution: for light, of any given wavelength, large telescopes produce less diffraction than small ones
Chapter 3: Question 30
Which of the following is NOT a reason to use a reflecting telescope rather than a refractor?
Chapter 3: Question 11
The light-gathering ability of a telescope is most dependent on the diameter of its primary objective. True or False?
Chapter 3: Question 13
A telescope with an 8-inch mirror will collect twice as much light as one with a 4-inch mirror.
True or False?
Chapter 3: Question 14
The 400" Keck reflector can see objects 100 times fainter than the 40" Yerkes lens. True or False?
Chapter 3: Question 15
Radio telescopes have poorer angular resolution than optical telescopes because radio waves have a much longer wavelength than optical waves. True or False?
Chapter 3: Question 39
What is the resolution of a telescope?
Chapter 3: Question 42
Green light has a shorter wavelength than orange light. In a 5 inch telescope, green light will...
Chapter 3: Question 18
The opacity of the atmosphere is partially corrected via adaptive optics. True or False?
Chapter 3: Question 43
What problem does adaptive optics correct?
Reflecting Telescopes characterisitics and examples:
-World's largest telescope
-Most commonly used by professionals astronomers today
-Ex: The Hubble Space Telescope
Refracting Telescopes characteristics and examples:
-Incoming light passes through glass
-Very large telescopes become "top-heavy"
-The world's largest is 1-meter in diameter
-Ex: Galileo's Telescopes
Chapter 3: Question 20
Optical telescopes are usually used only at night, but radio telescopes can be used day or night. True or False?
Chapter 3: Question 21
The Earth's atmosphere is the major factor limiting the use of ground-based radio telescopes. True or False?
Chapter 3: Question 22
Optical interferometry is more in use than radio interferometry. True or False?
Chapter 3: Question 44
What is true of radio telescopes?
Chapter 3: Question 46
In astronomy, an interferometer can be used to...
Chapter 3: Question 28
Galaxies look the same whether viewed in visible or X-ray wavelengths. True or False?
Chapter 3: Question 27
The Compton GRO was the first telescope used for our exploration of high-energy astronomy. True or False?
Chapter 3: Question 26
The mirrors for X-ray telescopes are the same shape as those of optical reflectors. True or False?
Chapter 3: Question 25
Due to our ozone layer, ultraviolet astronomy must be done from space. True or False?
Chapter 3: Question 24
Like radio and optical astronomy, infrared astronomy is easily done with ground-based telescopes. True or False?
Chapter 3: Prelecture Question 14
Which of the following regions of the elctromagnetic spectrum is useful for studying distant galaxies?
Chapter 3: Question 50
Which of the following is currently supplying high resolution X-ray images from space?
Conceptual Self-Test 3.02
The term seeing is used to describe how faint an object can be detected by a telescope. True or False?
Conceptual Self-Test 3.03
One of the primary advantages of CCDs over photographic plates is the former's high efficiency in detecting light. True or False?
Conceptual Self-Test 3.04
Radio telescopes are large in part to improve their angular resolution, which is poor because of the long wavelengths at which they are used to observe the skies. True or False?
Conceptual Self-Test 3.05
Infared astronomy can only be done from space. True or False?
Conceptual Self-Test 3.06
Gamma-ray telescopes employ the same basic design that optical instruments use. True or False?
Conceptual Self-Test 3.07
Because gamma rays have very short wavelengths, gamma-ray telescopes can achieve extremely high angular resolution. True or False?
Conceptual Self-Test 3.08
The main reason that most professional research telescopes are reflectors is that...
Conceptual Self-Test 3.10
The primary reason professional observatories are built on the highest mountaintops is to...
Conceptual Self-Test 3.11
When multiple radio telescopes are used for interferometry, resolving power is most improved by...
Conceptual Self-Test 3.12
The Spitzer Space Telescope (SST) is stationed far from Earth because...
Conceptual Self-Test 3.13
The best way to study young stars hidden behind interstellar dust clouds would be to use...
Conceptual Self-Test 3.14 VIS
Resolution is sharpest when the ratio of wavelengths to telescope size is...
Conceptual Self-Test 3.15 VIS
The best frequency wave in which to study the hot (million-kelvin) gas found among the galaxies in the Virgo cluster would be...
Chapter 1: Question 16
In Ptolemy's geocentric model, retrograde motion occurs when the planet is closest to us, on the inside portion of...
Chapter 1: Question 14
In Ptolemy's geocentric model, the planet's motion along its deferent is all that is needed to understand retrograde motion. True or False?
Chapter 1: Question 22
Which of these was NOT seen telescopically by Galileo?
Chapter 1: Question 12
Galileo's observations of the entire phase cycle of Venus proved that Ptolemy's epicycles could not be correct in keeping Venus between us and the Sun. True or False?
Vocabulary in Context: Kepler's Planetary Orbits
1. Earth is located at one __ of the Moon's orbit.
2. According to Kepler's second law, Jupiter will be traveling most slowly around the Sun when at __.
3. Earth orbits in the shape of a/an __ around the Sun.
4. The mathematical form of Kepler's third law measures the period in years and the __ in astronomical units (AU).
5. According to Kepler's second law, Pluto will be traveling fastest around the Sun when at __.
6. The extent to which Mars' orbit differs from a perfect circle is called its __.
-Aphelion: greatest distance from the Sun
-Perihelion: point of closest approach to the Sun
-Eccentricity: how far off an orbit is from an elliptical path
Ranking Task: Kepler's Third Law of Planetary Motion
1. Planets move fastest when they are at the __ (right side).
2. Planets move slowest when they are at the __ (left side).
3. Planetary Orbits go __.
4. Does mass effect orbital periods?
5. Kepler's Third Law formula is __.
5. P^2 (in Earth)=A^3 (in AU)
Ranking Task: Kepler's Second Law
1. Kepler's second law states: an imaginary line connecting the Sun to any planet sweeps out __of the ellipse in __.
2. When a planet is ___ to the Sun it moves ___ than when ___ away.
3. When an object is __ to the Sun then, it covers ___ than when it was ___.
1. equal areas/ equal intervals of time
3. close/greater distance/farther away
Chapter 1: Question 8
Kepler found the orbits of planets are ellipses, not circles. True or False?
Chapter 1: Question 25
Tycho Brahe's contribution to Kepler's Laws of Planetary Motion were...
Chapter 1: Question 3
According to Newton's Second Law, if you double the force acting on a body, the acceleration will double. True or False?