Telescopes: Objectives

Telescopes are the tools that we use to collect light

Telescopes are "light buckets"

Why large telescopes? (Is bigger really better?)

Advantages and disadvantages of different wavelengths

Need for Multi-Wavelength Astronomy

Optical Telescopes

A telescope's primary purpose is to collect light

"light bucket"

Not to magnify

2 main types: Reflecting and Refracting

The path of light can be traced= ray tracing

Optical Telescopes

2 main types: Reflecting and Refracting

How a Simple Telescope Works

Optical Telescope Designs

Disadvantages of Refractors (Lenses)

Chromatic Aberration

Imaging and Non-Imaging Detectors

Imaging

Photographs

CCDs (Charge-coupled devices)

Properties of Telescopes

Light gathering power = collecting area

Collecting area is proportional to surface area, R²

Angular Resolution

Collecting Power

Angular Resolution

Problems with Ground based Astronomy

Active Optics

High Resolution Imaging

Adaptive Optics

Radio Astronomy

High-Resolution Radio Astronomy

High-Resolution Radio Interferometry

Multi-Wavelength Astronomy

Multi-Wavelength Astronomy

X-Ray Imaging Telescope

Multi-Wavelength View of the Milky Way Galaxy

Review

Motions of Earth around Sun

Parallax, apparent motions of stars, eclipses, phases of the moon and inferior planets, etc.

Copernican revolution

Kepler's contributions

Newton's laws of gravity

Review

Light-

photons are waves that also behave like particles at times

Photons have a characteristic wavelength, frequency, and energy

Spectra

Kirchhoff's Laws

Telescopes- angular resolution and collecting power, refractors vs. reflectors

Why space based telescopes are necessary