Course Hero Logo

Waves while a hot bright object will emit more uv o

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 14 - 17 out of 47 pages.

waves while a hot bright object will emit more UVoEx: using a light dimmer on an incandescent light bulb(produces light through blackbody radiation)  as light isdimmed and filament temp decreases, distribution of colorshifts toward longer wavelengths and light appearsredder/dimmer°Doppler Effect:One of the most important measurement techniques in modernastronomyIf moving toward source of radiation, the wavelengths seem shorter(blue) – if moving away, they seem longer (red)Stars don’t change color but perceived change is the result of theobservers motionDoppler depends only on the relative motion of the source and theobserverIn addition to using radiation, astronomers will also use info fromlight’s spectrum to see what is in space or how fast it is movingtoward/away from usDoppler can use thermal broadening of spectral linesoRotation will also cause broadening of spectral lines throughthe Doppler effect  how they determine rotational speeds offaraway bodies°Spectroscopy:Spectroscope splits incoming radiation into component wavelengths(light into colors)  radiation can be measuredAbsorption AND emission spectrums can be BOTH used to identifyelementsAstronomers use the laws of spectroscopy to analyze radiation frombeyond earth – A nearby star or distant galaxyIf there is movement – Doppler effect TAKES OVER  spectral linescan changeEmission spectrum determines color of object°°Lecture 4: Telescopes°Telescope:
A device used to collect as much light as possible from some distantsource and deliver it to a detector for detailed studyOptical telescopes are designed specifically to collect wavelengthsthat are visible to the human eye  been around since time ofGalileoMore recently telescopes are designed to collect wavelengths NOTvisible to the human like:oRadiooInfraredoUVoHigh E°Optical Telescopes:2 categories:oRefractingRefraction = bend of beam of light as it passes througha transparent medium into another (straw will seembent when its not)Angle of prism light is passing through will determineangle of deflection caused by refractionLens used in refraction telescope like series of prismsUse a lens that refracts all light to meet at a focus pointFocal length = length from refracting lens to focuspointDisadvantages: (why most modern telescopes usereflection instead of refraction)CHROMATIC ABERATION: fact that all light mustpass though the lens = major disadvantagebecause as reds and blues tend to focusdifferently = a HALO appears no matter where wefocusAs light passes through lens – some absorbed byglass  mostly an issue with UV or infraredradiationLarge lens = heavyLargest ever made in 1897 still used = 1 min diameterDifficult to accurately polish the 2 surfaces of alens – must be done with high accuracy
oReflectingUse a curves mirror instead of lens to focus incoming

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 47 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
N/A
Tags

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture