Upload
others
View
6
Download
0
Embed Size (px)
Citation preview
• Powers of a telescope"– Light Gathering Power"– Resolving Power"– Magnification "
• Types of telescopes / Definition of telescope"– Refractor"– Reflector "
• Atmospheric distortion"– Seeing"– Reddening and Extinction"– Atmospheric lines "
Lecture 7, Part I: Telescopes"
Yerkes Observatory, circa 1890"
Light Gathering"Want a large
collecting area or “light bucket.”"Flux ratio = (D2/D1)2
m1 - m2 = -2.5 x log(Flux ratio)"
Deye = 5 mm = 5x10-3 m"Dtel = 1 m "
(Dtel/Deye)2 = (1m / 5x10-3m)2 = 4x104"
m1 – m2 = -2.5 x log(4x104) = -11.5 mag"
For Example:"
Light Gathering"Want a large
collecting area or “light bucket.”"Flux ratio = (D2/D1)2
m1 - m2 = -2.5 x log(Flux ratio)"
Deye = 5 mm = 5x10-3 m"Dtel = 1 m "
(Dtel/Deye)2 = (1m / 5x10-3m)2 = 4x104"
m1 – m2 = -2.5 x log(4x104) = -11.5 mag"
For Example:"
Light Gathering"Want a large
collecting area or “light bucket.”"Flux ratio = (D2/D1)2
m1 - m2 = -2.5 x log(Flux ratio)"
Getting above the atmosphere is even better!"
Deye = 5 mm = 5x10-3 m"Dtel = 1 m "
(Dtel/Deye)2 = (1m / 5x10-3m)2 = 4x104"
m1 – m2 = -2.5 x log(4x104) = -11.5 mag"
For Example:"
D"
slit" screen"Resolving Power Diffraction"The wave nature of
light."
arcsecond"
For Example:"
Δθ = λ/D"
The atmosphere messes up resolution too…"
Wave Nature of Atoms"
Telescopes"• Refractor:"
• Reflector: "
Telescopes"Common reflecting telescopes include"
• Newtonian"• Cassegrain"• Coudé"
Photometry"
Spectroscopy"
The Telescopes of Mauna Kea"
Atmospheric distortions:“Seeing”"
Adaptive Optics"
Atmospheric distortions:“Seeing”"
Adaptive Optics"
• Young stars"• Bound orbits"• Probe the
potential"• Fix the position "• No assumptions"• Isotropic"
Gillessen et al 2010"
scale ~ few light days"
The S Stars"
• Young stars"• Bound orbits"• Probe the
potential"• Fix the position "• No assumptions"• Isotropic"
Gillessen et al 2010" The S Stars"
Hubble Space Telescope"
Δθ = (2.06x105)(5.5x10-7 m) / 1m
= 1.1x10-1 arcsec"
recall: 1 radian = 206,264.806 arcsec"
James Webb Space Telescope"
The Spitzer Space Telescope"
Sofia
Radio Telescopes"
Radio Telescopes"
Interferometers"
Radio Telescopes"
Radio Telescopes"
Radio/Sub-mm Telescopes: ALMA"
X-ray Telescopes"
X-ray Telescopes"
X-ray Spectroscopy"