What is Astronomical spectroscopy?
'''Astronomical spectroscopy''' is the [[science]] of using [[spectroscopy]] to figure out what elements [[astronomy|astronomical]] bodies, such as [[stars]], [[planets]] and [[nebula]]e, are made of. It can also be used to work out how those objects are moving, using [[doppler shift]]. The study of [[spectroscopy]] and [[spectra]] is used in astronomy to help scientists study the whole [[electromagnetic spectrum|spectrum]] of [[electromagnetic radiation]], including visible light, which radiates from [[star]]s and other hot celestial objects. Spectroscopy can be used to find properties of distant stars and galaxies. It can find out their [[chemical]] composition, [[temperature]], [[density]], [[mass]], [[distance]], [[luminosity]], and relative [[motion]] using doppler effect measurements. == Chemical properties of stars == [[Image:Spectral lines continuous.png|thumb|[[Spectrum|Continuous spectrum]]]] [[Image:Spectral lines emission.png|thumb|[[Emission spectrum|Emission lines]]]] [[Image:Spectral lines absorption.png|thumb|[[Absorption spectroscopy|Absorption lines]]]] [[Isaac Newton]] used a prism to split white light into a spectrum of color, and [[Fraunhofer]]'s high-quality prisms allowed scientists to see dark lines of an unknown origin. It was not until the 1850s that [[Gustav Kirchoff]] and [[Robert Bunsen]] explained the dark lines. Hot solid objects produce light with a continuous [[spectrum]], and hot gasses emit light at specific wavelengths. However, hot solid objects surrounded by cooler gasses show a near-continuous spectrum with ''dark lines corresponding to the emission lines of the gasses''.<ref name=Hearnshaw>Hearnshaw J.B. 1986. ''The analysis of starlight''. Cambridge University Press, 42–44. {{ISBN|0-521-39916-5}}</ref> By comparing the [[absorption spectroscopy|absorption lines]] of the [[Sun]] with [[Emission spectrum|emission spectra]] of known gasses, the chemical composition of stars can be discovered. == References == {{reflist}} [[Category:Astrophysics]] [[Category:Spectroscopy