Astro-Tools of the Trade - o Uses a mirror to bring light...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Tools of the Trade Primary purpose is to collect more light Typical large telescope: D = 6 m mirror o Dilated pupil: d = 6mm A = area = piR^2 = pi D^2/4 Ratio of areas =A 2 /A 1 = D 2 2 /D 2 1 = (D 2 /D 1 ) 2 A large telescope also provides higher resolution – the ability to detect fine detail. o But turbulence in the atmosphere blurs the image (at optical wavelengths especially) o Atmosphere throws the light around from the stars With a long exposure you’d just get one big blur Refracting Telescopes o Light is bent (“refracted”) by lens and brought to a focus o Binocular = a pair of small refracting telescopes o Purpose of a telescope is to take a large area of light and concentrate it into a small area o Galileo first to use telescope for astronomy o James Lick – donated his fortune to build an observatory in San Jose o Simple to make, but they suffer from several problems, including chromatic aberration Different colors of light focus at different lengths Reflecting Telescopes
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: o Uses a mirror to bring light to a focus o Suffer from spherical aberration if curve is not the right angle o Paraboloid or hyperboloid allow for a single focus Radio Telescope o Much bigger areas needed Telescopes in Space o Advantages: No distortion by atmosphere Darker sky (especially for infrared) You cant get all of the different kinds of light from the ground Uv/x-ray/gamma ray/infrared/ O-Zone, water vapor, and other molecules are bypassed Twinkiling of Stars o Air bends starlight Due to atmospheric turbulence, the bending varies with time, so the amount of light hitting your eye varies. o Star closer to horizon more air, more turbulence more twinkling. o This is related to blurring of a stars image: it doesnt like point-like. o Planets dont usually twinkle, stars do Adaptive Optics o Changes the light waves to flat when they are actually jumping around...
View Full Document

This note was uploaded on 04/04/2008 for the course ASTRO C 10 taught by Professor Filippenko during the Fall '08 term at University of California, Berkeley.

Ask a homework question - tutors are online