ASTR 1101-001Spring 2008

Joel E. Tohline, Alumni Professor

247 Nicholson Hall

[Slides from Lecture22]

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a convex lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

Landolt Astronomical Observatory

http://www.phys.lsu.edu/landoltobservatory/index.html

Location: roof of Nicholson Hall

11.5-inch refracting telescope

Refracting Telescope: “How it works”

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

NOTE: A large lens is advantageous because it can collect more light in a given amount of time. The collecting area goes as the square of the radius of the lens.

40-inch Refractor at Yerkes Observatory(near Chicago, IL)

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a convex lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

Highland Road Park Observatory(BREC park just south of Siegen Lane)

http://www.bro.lsu.edu

20-inch diameter reflecting telescope

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

NOTE: A large mirror is advantageous because it can collect more light in a given amount of time. The collecting area goes as the square of the radius of the mirror.

Reflecting Telescope:“Gemini North” in Hawaii

1. Primary mirror has a diameter of 8.1 meters

2. Secondary mirror has a diameter of 1.0 meter

3. Hole in primary through which light passes to reach the Cassegrain focus

Summit of Mauna Kea (Hawaii)

Hubble Space Telescope

Operated by:Space Telescope Science Institutein Baltimore, Marylandwww.stsci.edu

Hubble Space Telescope

Operated by:Space Telescope Science Institutein Baltimore, Marylandwww.stsci.edu

NOTE: Hubble does not have aparticularly large primary mirror.Hubble images are not “fuzzy,”however, because its view of objectsis unhampered by atmospheric turbulence.

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

64-meter “Parkes” Radio TelescopeNew South Wales, Australia

Very Large Array (VLA) of Radio TelescopesSocorro, New Mexico

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• SIRTF (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• GRO (-ray)

Telescopes (Chapter 6)

• Traditional ground-based optical telescopes– Refracting (light passes through a lens)– Reflecting (light bounces off a concave mirror)

• Telescopes for wavelengths outside the visible part of the EM spectrum– Ground-based radio telescopes and telescope arrays– Space-based satellite telescopes

• Spitzer Space Telescope (infrared)• Hubble Space Telescope (visible and ultraviolet)• Chandra & XMM (x-ray)• Compton Gamma-Ray Observatory (-ray)

Spitzer

Spitzer Space Telescope (infrared)

Hubble

Hubble Space Telescope (visible & UV)

Operated by:Space Telescope Science Institutein Baltimore, Marylandwww.stsci.edu

Chandra & XMM

Chandra X-ray Observatory

Compton GRO

Compton Gamma-Ray Observatory (CGRO)