Ch. 3 TELESCOPES.

Slides:

Advertisements

Similar presentations

Astronomy Notes to Accompany the Text

Advertisements

Astronomy Seeing through different light…. VisibleUV..

Chapter 6: Telescopes – Portals of Discovery. Visible light is only one type of electromagnetic radiation emitted by stars Each type of EM radiation travels.

Optics and Telescopes Chapter Six. Telescopes The fundamental purpose of any telescope is to gather more light than the naked eye can In many cases telescopes.

Chapter 5 Telescopes. 5.1 Optical Telescopes The Hubble Space Telescope 5.2 Telescope Size The Hubble Space Telescope 5.3 Images and Detectors Diffraction.

Light and Telescopes Please pick up your assigned transmitter

Telescopes Analyzing electromagnetic spectra to search for understanding of celestial objects.

Chapter 6 Optics and Telescopes

© 2011 Pearson Education, Inc. Lecture Outlines Astronomy Today 7th Edition Chaisson/McMillan © 2011 Pearson Education, Inc. Chapter 5.

1 Earth’s Atmosphere & Telescopes Whether light is absorbed by the atmosphere or not depends greatly on its wavelength. Earth’s atmosphere can absorb certain.

Telescopes. Act as “electromagnetic radiation catchers” Capture as much as possible Focus Magnifies images Telescopes that “catch” visible light are called.

January 24, 2006Astronomy Chapter 5 Astronomical Instruments How do we learn about objects too far away for spacecraft? How do telescopes work? Do.

Telescopes and Astronomical Instruments The 2 main points of telescopes are 1)To make images with as much angular information as possible 2)To gather as.

Optics and Telescopes Chapter Six.

Telescopes. Magnification (make things look bigger) easy to make a telescope with good magnification Collection of large amounts of light (see fainter.

Light and Telescopes Chapter 6. Previous chapters have described the sky as it appears to our unaided eyes, but modern astronomers turn powerful telescopes.

Land Based Telescopes. Telescopes: "light buckets" Primary functions: 1. ___________ from a given region of sky. 2. ______ light. Secondary functions:

Reflective Refractive Spectro scopy Space Large telescopes How Optical works $ 200 $ 200$200 $ 200 $ 200 $400 $ 400$400 $ 400$400 $600 $ 600$600 $

Chapter 5 Telescopes: “light bucket”. Telescopes have three functions 1.Gather as much light as possible: LGP ∝ Area = πR 2 LGP ∝ Area = πR 2 Why? Why?

Chapter 6: The Tools of the Astronomer. Telescopes come in two general types Refractors use lenses to bend the light to a focus Reflectors use mirrors.

How do Astronomers know what they know? Almost everything we know about Astronomy was learned by gathering and studying light from distant sources Properties.

Telescopes. Act as “electromagnetic radiation catchers” Capture as much as possible Focus Magnifies images Telescopes that “catch” visible light are called.

How do we study the Universe?. SPECTROSCOPY Uses visible wavelength split into colors.

New Improved Eyes Telescopes and “Invisible” Astronomy.

Optics and Telescopes. Optics and Telescopes: Guiding Questions 1.How do reflecting and refracting telescopes work? 2.Why is it important that professional.

Tools for Studying Space. © 2011 Pearson Education, Inc. Telescopes.

Telescopes Instrument to gather as much EMR as possible and concentrate it into a focused beam. Optical telescopes gather visible light. Other telescopes.

Astronomical Tools. Essential Questions 1.What is Light? 2.How do telescopes work, and how are they limited? 3.What kind of instruments do astronomers.

Telescopes Notes.

Lecture Outlines Astronomy Today 7th Edition Chaisson/McMillan © 2011 Pearson Education, Inc. Chapter 5.

Chapter 3 Telescopes. Gemini North Telescope, Mauna Kea, Hawaii.

Telescopes. Light Hitting a Telescope Mirror huge mirror near a star * * * small mirror far from 2 stars In the second case (reality), light rays from.

Chapter 5 Telescopes Chapter 5 opener. This composite photograph shows two of the premier optical telescopes available to astronomers today. At the top,

Chapter 4: Telescopes. E O Optical telescopes: Reflectors and refractors Refractors use lenses E: eyepiece O: objective.

1 Earth’s Atmosphere & Telescopes Whether light is absorbed by the atmosphere or not depends greatly on its wavelength. Earth’s atmosphere can absorb certain.

TELESCOPES. Where do we put telescopes to have the best viewing conditions? 1. On Earth: CLEARHIGHDRYCOLDDARK.

Astronomy: A Beginner’s Guide to the Universe Seventh Edition © 2013 Pearson Education, Inc. Chapter 3 Lecture Telescopes.

The Very Large Array (VLA) in New Mexico. Observations at wavelengths other than visible light are revealing previously invisible sights Visible light.

Universe Tenth Edition Chapter 6 Optics and Telescopes Roger Freedman Robert Geller William Kaufmann III.

Astronomical Observations TypeAtmosphere  Radio WavesNo effect  MicrowavesMostly blocked  InfraredBlocked  Visible LightSlight blurring  UltravioletBlocked.

Telescopes. Light Hitting a Telescope Mirror huge mirror near a star * * small mirror far from a star In the second case (reality), light rays from any.

Refracting Telescopes 24.2 Tools for Studying Space  A refracting telescope is a telescope that uses a lens to bend or refract light.  Focus The most.

 From the ground the atmosphere distorts images.  Light pollution from streetlights, city lights, car lights, and more hinders the seeing conditions.

Optics and Telescopes Chapter Six. Some Guiding Questions 1.Why is it important that telescopes be large? 2.Why do most modern telescopes use a large.

Telescopes Portals of Discovery

Telescopes and Astronomical Instruments

Chapter 6 Telescopes: Portals of Discovery

Homework #4 What is the maximum resolution of your eyes (assume the wavelength range that your eyes are sensitive to is 300 – 700 nm and that your iris.

Chapter 6 Astronomical Instruments

© 2017 Pearson Education, Inc.

TELESCOPES ALLOW US TO STUDY SPACE FROM EARTH!!!

Structure and Function

Chapter 6 Telescopes: Portals of Discovery

Light and Telescopes

The Tools of the Astronomer

© 2017 Pearson Education, Inc.

Telescopes Chapter 3 Objectives To know the general types of telescopes and the advantages and disadvantages of each one. To know the primary parts.

Ch. 6 - Astronomical Instruments (Telescopes)

6.3 Telescopes and the Atmosphere

Ch.1, Sec.2 - Telescopes Optical Telescopes

TELESCOPES ALLOW US TO STUDY SPACE FROM EARTH!!!

Using Telescopes to Observe Electromagnetic Radiation in Space

Telescopes and the Electromagnetic Spectrum Section 3

Astronomical Observations What Wavelengths To Use?

Optics and Telescopes Chapter Six.

Telescopes Lecture.

Presentation transcript:

Ch. 3 TELESCOPES

INTRO observation usually precedes theory. In astronomy, observation usually precedes theory. Ex/ New solar syst.; acc. univ. Telescopes have grown in size and complexity and now cover the entire EM spectrum

I. Optical Telescopes A. Telescope: A “light bucket” used to capture incoming photons & concentrate them into a focused beam for analysis.

B. Types of Telescopes Refractors: A glass lens bends (refracts) incoming light rays to a focus. Eyepiece magnifies.

Yerkes Observatory

2. Reflectors: A curved mirror (the primary mirror) reflects incoming rays to a focus. Eyepiece magnifies.

D. Reflector Design 1.Newtonian: Secondary mirror reflects light to side eyepiece. Subcategory: Dobsonian

2. Cassegrain: Secondary mirror reflects light back thru a hole in the primary mirror.

II. Telescope Size & Resolution A. Light-gathering power: Larger collecting area - brighter image. 1. Brightness ~ Diameter2 Ex/ 10” aperture is 25 x brighter than 2” aperture (or 25 x faster exposure) 2. Largest: VLT in Chile (16 m) Keck I & II in Hawaii (14 m) TMT (2018); Giant Magellan Telescope (2016)

Ch. 5 Example Problem How long would it take a telescope with a 9” aperture to produce the same image that a 3” scope can make in 45 min.?

The VLT

GranTeCan

Canary Islands

GMT: 7 8.4-m mirrors

B. Resolving Power: Ability to make sharp images of faint objects or to distinguish between 2 adjacent objects in the sky.** aka Angular Resolution

C. Atmospheric Blurring 1. Hinders ground-based scopes Ex/ “twinkling” stars 2. Best locations- high, dry, & dark Ex/ Arizona; Chile; Hawaii 3. Another solution - space. Ex/Hubble (1993) - 20 x better than previous best

Pic Du Midi, French Pyrenees

D. Adaptive Optics: Mirror changes shape to compensate for atmosphere. a. Lasers pierce atmosphere, create “artificial star” b. Some now sharper than Hubble! Ex/ Subaru (IR), Keck, VLT

III. Radio Astronomy & Interferometry A. Radio telescopes 1. Only since the‘50’s Grote 2. Pioneers- Karl Jansky, Reber 3. Curved metal dish focuses radio waves to a focal point. 4. Instruments located at the prime focus.

B. Large Size Necessary 1. Signals are faint 2 B. Large Size Necessary 1. Signals are faint 2. Long wavelength radio diffracts greatly - poor resolution a. Surface doesn’t have to be smooth like optical scopes b. It’s easy to make them large Ex/ Largest: Arecibo – 1000 ft. wide!(305 m)

Green Bank, West Virginia - largest moveable radio dish

C. Value of Radio Astronomy 1. 24 / 7 2. Thru clouds, rain, snow 3 C. Value of Radio Astronomy 1. 24 / 7 2. Thru clouds, rain, snow 3. Objects visibly dim may be strong radio sources. Ex/ *4. Radio penetrates dust in space. Ex/ Center of our galaxy

1. Interferometer: Data from 2 or more scopes combined. D. INTERFEROMETRY 1. Interferometer: Data from 2 or more scopes combined. Ex/ VLA in N. Mex (27 dishes) ATA (2007)- 42 dishes ALMA (2012) - 66 Square Kilometer Array (2020) - 150 dishes 2. Behaves like a single dish whose diameter is the distance between dishes. Ex/ Compound eye

Allen Telescope Array (so far..)

Single Dish of the VLA

VLA in New Mexico

ALMA

Largest Telescopes 2015 Refractor (lens) Yerkes Obs. 1 m Single mirror GranTeCan Keck I & II 10.4 m 10 m Optical interferometer VLT Keck 16.4 m 14.6 m Single radio dish Arecibo 305 m Array (1 location) ATA (phase 1) VLA ALMA 42 dishes 27 dishes 66 dishes

A. Microwave satellites IV. Space Telescopes A. Microwave satellites COBE (1990’s) - Measured the cosmic microwave background Proof of the Big Bang! 2. Planck (2009)

B. INFRARED Astronomy 1. Long wavelength IR penetrates clouds in space B. INFRARED Astronomy 1. Long wavelength IR penetrates clouds in space. 2. Good for star or planet-forming clouds of warm dust & gas. 3. Mountaintops Ex/ Subaru 4. Airplanes Ex/ SOFIA 5. Or Space Ex/ Spitzer James Webb Space Tel. (2018)

SUBARU

SOFIA

James Webb Space Telescope “Successor to the Hubble” mirror Launch in 2018 (?) Infrared

C. Visible light: 1.Hubble Space Telescope 2. Spherical aberration corrected 1993 3. Final repair mission 2009

D. ULTRAVIOLET Astronomy 1. Used for hot stars 2. Done by high-altitude balloons 3. Or satellites Ex/ Galex, Hubble E. X-RAY Astronomy 1. No ground - only satellites 2. Used 4 violent events (black holes) 3. Special design (difficult to focus) Ex/ Chandra (1990’s)

X-ray detectors

F. GAMMA RAY Astronomy 1. Can’t be focused 2 F. GAMMA RAY Astronomy 1. Can’t be focused 2. Counted by special detectors 3. Scarce (~ 1 detection per day) 4. Occasional “bursts”, or GRB’s a. Hypernova – really massive star explodes / black hole formed b. Colliding binary neutron stars 5. Compton Gamma Ray Observatory (1990’s - 2000)

6. SWIFT (2004)

7. Fermi Gamma-Ray Space Telescope