LECTURE 7, SEPTEMBER 14, 2010 ASTR 101, SECTION 3 INSTRUCTOR, JACK BRANDT 1ASTR 101-3, FALL 2010

2

3

4

5

6

7

Question 1 Modern telescopes use mirrors rather than lenses for all of these reasons EXCEPT a) light passing through lenses can be absorbed or scattered. b) large lenses can be very heavy. c) large lenses are more difficult to make. d) mirrors can be computer controlled to improve resolution. e) reflecting telescopes aren’t affected by the atmosphere as much.

Question 1 Modern telescopes use mirrors rather than lenses for all of these reasons EXCEPT a) light passing through lenses can be absorbed or scattered. b) large lenses can be very heavy. c) large lenses are more difficult to make. d) mirrors can be computer controlled to improve resolution. e) reflecting telescopes aren’t affected by the atmosphere as much. Reflecting instruments like the KECK telescopes can be made larger, and more capable, than refractors.

ASTR 101-3, FALL

ASTR 101-3, FALL

ASTR 101-3, FALL

Question 4 Resolution is improved by using a) larger telescopes & longer wavelengths. b) infrared light. c) larger telescopes & shorter wavelengths. d) lower frequency light. e) visible light.

Question 4 Resolution is improved by using a) larger telescopes & longer wavelengths. b) infrared light. c) larger telescopes & shorter wavelengths. d) lower frequency light. e) visible light. Diffraction limits resolution; larger telescopes and shorter- wave light produces sharper images.

ASTR 101-3, FALL

a) the quality of the telescope’s optics. b) the transparency of a telescope’s lens. c) the sharpness of vision of your eyes. d) the image quality due to air stability. e) the sky’s clarity & absence of clouds. Seeing in astronomy is a measurement of Question 2

Seeing in astronomy is a measurement of Question 2 “Good Seeing” occurs when the atmosphere is clear and the air is still. Turbulent air produces “poor seeing,” and fuzzier images. a) the quality of the telescope’s optics. b) the transparency of a telescope’s lens. c) the sharpness of vision of your eyes. d) the image quality due to air stability. e) the sky’s clarity & absence of clouds. Point images of a star Smeared overall image of star

ASTR 101-3, FALL

ASTR 101-3, FALL

ASTR 101-3, FALL

Question 8 Radio telescopes are useful because a) observations can be made day & night. b) we can see objects that don’t emit visible light. c) radio waves are not blocked by interstellar dust. d) they can be linked to form interferometers. e) All of the above are true.

Question 8 Radio telescopes are useful because a) observations can be made day & night. b) we can see objects that don’t emit visible light. c) radio waves are not blocked by interstellar dust. d) they can be linked to form interferometers. e) All of the above are true. The Very Large Array links separate radio telescopes to create much better resolution.

ASTR 101-3, FALL

ASTR 101-3, FALL

Question 9 Infrared telescopes are very useful for observing a) pulsars & black holes. b) from locations on the ground. c) hot stars & intergalactic gas. d) neutron stars. e) cool stars & star-forming regions.

Question 9 Infrared telescopes are very useful for observing a) pulsars & black holes. b) from locations on the ground. c) hot stars & intergalactic gas. d) neutron stars. e) cool stars & star-forming regions. Infrared images of star-forming “nurseries” can reveal objects still shrouded in cocoons of gas and dust.

ASTR 101-3, FALL

ASTR 101-3, FALL

ASTR 101-3, FALL

REVIEW-CHAPTER 0 Foundations of Astronomy Scientific Method, Powers of 10 Celestial Sphere, Seasons Angles, Ecliptic Precession Moon Phases, Eclipses Parallax ASTR 101-3, FALL

REVIEW, CHAPTER 1 Geocentric vs. Heliocentric Solar System Famous Names in Historical Astronomy & Their Contributions Copernicus, Galileo, Tycho, Kepler, Newton Retrograde Motion, Venus Phases Kepler’s Laws and the AU Newton’s Laws & Gravitation Orbits, Masses ASTR 101-3, FALL

REVIEW, CHAPTER 2 Light and Its Importance in Astronomy Wave description vs. Photons Electromagnetic (EM) Spectrum Atmospheric Transmission & Windows Atoms, Absorption & Emission of Photons Uses of Spectra in Astronomy Doppler Effect ASTR 101-3, FALL

REVIEW, CHAPTER 3 Optical Telescopes, Basic Types Light Gathering Power Resolving Power or Resolution Atmospheric Effects Radio Telescopes Infrared (IR) Images X-Ray Images ASTR 101-3, FALL

TEST NO. 1, SEPTEMBER 16, 2010 Multiple Choice, 40 Questions Paper Copy Plus Bubble Sheet Paper Copy Will Be Color Coded Identification Number Is Your Banner Number, Code It In As “Identification Number” Starting With Column A BRING A NO. 2 PENCIL ASTR 101-3, FALL

TEST NO. 1, SEPTEMBER 16, 2010 Bring A No. 2 Pencil Circle Your Answer On the Paper Copy And Fill In The Bubble Sheet Turn In Both Copies So The Different Color Tests Are Graded With The Correct Answer Sheet! BRING A NO. 2 PENCIL! ASTR 101-3, FALL