PHY 113 Lecture Notes - Lecture 5: Supernova Remnant, Active Optics, Square Kilometre Array
9 Jun 2018
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Chapter 5 Telescopes
5.1 Optical Telescopes
The Hubble Space Telescope
5.2 Telescope Size
5.3 Images and Detectors
5.4 High-Resolution Astronomy 5.5 Radio Astronomy
5.6 Interferometry
5.7 Space-Based Astronomy 5.8 Full-Spectrum Coverage
5.1 Optical Telescopes
Refracting lens
Images can be formed through reflection or refraction
Reflecting mirror
Reflecting and refracting telescopes
Modern telescopes are all reflectors:
• Light traveling through a lens is refracted
differently depending on wavelength
• Some light traveling through lens is absorbed
• Large lens can be very heavy, and can only be supported at edge
• A lens needs two optically acceptable surfaces; mirror needs only one
Modern telescopes are all reflectors:
• In other words, it’s much easier to make very large mirrors than very large lenses!
Types of reflecting telescopes
The Keck telescope, a modern research telescope
Uranus, Saturn (both from Keck)
Discovery 5-1: The Hubble Space Telescope
The Hubble Space Telescope has a variety of detectors
The Hubble Space Telescope’s main mirror is 2.4 m in diameter and is designed for visible,
infrared, and ultraviolet radiation
Here we compare the best ground-based image of M100, on the left, with the Hubble images
on the right
HST has provided some of the most amazing scientific data, and some of the most amazing
images mankind has ever witnessed in regards to astronomy and the nature of the universe.
Sit, back, relax, and let us all appreciate the depth and range of what Hubble has shown us
about God’s Creation.
“The heavens declare the glory of God...” –Psalm 19:1
“Stellar Nursery in the arms of NGC 1672”
5.2 Telescope Size
Light-gathering power: Improves detail Brightness proportional to square of radius of
mirror
Photo (b) was taken with a telescope twice the size of the telescope that took photo (a)
Resolving power: When better, can distinguish objects that are closer together
Resolution is proportional to wavelength and inversely proportional to telescope size—bigger
is better!
Note that images cannot becomes perfectly sharp, because light (like any wave) bends around
corners (think of the slit experiments).
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Images can be formed through reflection or refraction. Modern telescopes are all reflectors: in other words, it"s much easier to make very large mirrors than very large lenses! The hubble space telescope has a variety of detectors. The hubble space telescope"s main mirror is 2. 4 m in diameter and is designed for visible, infrared, and ultraviolet radiation. Here we compare the best ground-based image of m100, on the left, with the hubble images on the right. Hst has provided some of the most amazing scientific data, and some of the most amazing images mankind has ever witnessed in regards to astronomy and the nature of the universe. Sit, back, relax, and let us all appreciate the depth and range of what hubble has shown us about god"s creation. The heavens declare the glory of god psalm 19:1. Stellar nursery in the arms of ngc 1672 . Light-gathering power: improves detail brightness proportional to square of radius of mirror.
