Telescope Functions 1Gather Light

Gather Light 9x How much more light does the bigger telescope gather? r2r2

Telescope Functions eye Galileo’s telescope large amateur Mount Laguna space telescope Keck

Telescope Functions eye Galileo’s telescope large amateur Mount Laguna space telescope Keck 1/4”2”8”21”100”400”

Telescope Functions eye Galileo’s telescope large amateur Mount Laguna space telescope Keck 1/4”2”8”21”100”400” ,000 2,560,000

Telescope Functions 1Gather Lightr 2 2Resolution

Resolution

1Gather Lightr 2 2Resolution  = A = aperture Telescope Functions  A

Resolution eye Galileo’s telescope large amateur Mount Laguna space telescope Keck 1/4”2”8”21”100”400” ,000 2,560,000 11/81/321/841/4001/1600

1Gather Lightr 2 2Resolution  = 3Magnification Telescope Functions  A

Refraction fast slow fast smooth carpeted smooth

Refraction fast slow fast

Refraction fast slow

Refractors

Focus

Refractors

Reflectors

Central Obstruction 12” Refractor12” Reflector Which gathers more light?

tight space room moves around drinks spill

very high

closer to ground shorter telescope smaller dome

Nazysmith multiple instruments easily changed at a moments notice # depends on size of instruments and size of telescope

focus always in the same place one heavy instrument

Telescope Functions 1Gather Light 2Resolution 3Magnification

Resolution size chromatic aberration spherical aberration seeing

Chromatic Aberration

Acromats Reduce Chromatic Aberration

Spherical Aberration

Parabolic Mirror

Seeing

warm surface heats air hot air rises causes stars to twinkle mountaintop observatory above inversion layer no heat sources in observatory

Seeing Which is warmer on a sunny day, air or water? Since air is warmer, how can cold water warm air? stable air over water during day daytime observatories surrounded by water solar observatory

Seeing

Which is warmer at night, air or water? Solar observatories are terrible for nighttime use. seeing/time beach cruise

Resolution seeing adaptive optics

Refractor Reflector gathers more light chromatic aberration acromats very expensive shorter smaller housing spherical aberration parabolic mirrors still cheaper UV astronomy adaptive optics

Telescope Mount / Resolution altitude-azimuth stability equatorial tracking

Alt-Az

Equatorial

EquatorialAlt-Az

Radio Telescopes resolution  =  A

Radio Telescopes resolution  =  A A light radio

Radio Telescopes resolution  =  A A light500nm radio

Radio Telescopes resolution  =  A A light500nm radio20cm

Radio Telescopes resolution  =  A A light500nm1/4” radio20cm

Radio Telescopes resolution  =  A A light.00005cm.635cm radio20cm

Radio Telescopes resolution  =  A A light.00005cm.635cm radio20cm 254,000cm

Radio Telescopes resolution  =  A A light.00005cm.635cm radio20cm 2.54km

Radio Telescopes resolution  =  A A light.00005cm.635cm radio20cm1.6mi

Radio Telescopes arrays interferometry

Radio Telescopes arrays

Instrumentation image spectrum brightness

Image photochemical digital

Photochemical glass plates exposure time processing time scanning time dark room chemicals disposal archives

Digital CCD Charge Coupled Device single chip exposure time download time liquid nitrogen archives maintenance

Spectrum Take Notes at Telescope Record Image Analyze Image Later

Brightness Hipparchus magnitude logarithmic Five magnitudes lower means one hundred times as bright. brighter than 1 st fainter than 6 th

Photometer

Light Pollution

Photometer

CCD