Editing Spectral line (section)

{{Short description|Distinctive narrow spectral feature of chemical species}}
{{multiple image
| direction         = vertical
| width             = 320
| image1            = Spectral-lines-continuous.svg
| alt1              = Continuous spectrum
| caption1          = Continuous spectrum
| image2            = Spectral-lines-emission.svg
| alt2              = Emission lines
| caption2          = [[Emission spectrum|Emission lines]] ([[discrete spectrum]])
| image3            = Spectral-lines-absorption.svg
| alt3              = Absorption lines
| caption3          = Absorption spectrum with [[absorption lines]]
}}

A '''spectral line''' is a weaker or stronger region in an otherwise uniform and [[continuous spectrum]]. It may result from [[emission (electromagnetic radiation)|emission]] or [[absorption (electromagnetic radiation)|absorption]] of [[light]] in a narrow [[frequency]] range, compared with the nearby frequencies. Spectral lines are often used to identify [[atom]]s and [[molecule]]s. These "fingerprints" can be compared to the previously collected ones of atoms<ref>{{Citation| publisher = National Institute of Standards and Technology| last1 = Kramida| first1 = Alexander| last2 = Ralchenko| first2 = Yuri| title = NIST Atomic Spectra Database, NIST Standard Reference Database 78| journal = <!-- Deny Citation Bot-->| access-date = 2021-06-27| date = 1999| url = http://www.nist.gov/pml/data/asd.cfm}}</ref> and molecules,<ref name="RothmanGordon2013">{{cite journal |last1=Rothman|first1=L.S.|last2=Gordon|first2=I.E.|last3=Babikov|first3=Y.|last4=Barbe|first4=A.|last5=Chris Benner|first5=D.|last6=Bernath|first6=P.F.|last7=Birk|first7=M.|last8=Bizzocchi|first8=L.|last9=Boudon|first9=V.|last10=Brown|first10=L.R.|last11=Campargue|first11=A.|last12=Chance|first12=K.|last13=Cohen|first13=E.A.|last14=Coudert|first14=L.H.|last15=Devi|first15=V.M.|last16=Drouin|first16=B.J.|last17=Fayt|first17=A.|last18=Flaud|first18=J.-M.|last19=Gamache|first19=R.R.|last20=Harrison|first20=J.J.|last21=Hartmann|first21=J.-M.|last22=Hill|first22=C.|last23=Hodges|first23=J.T.|last24=Jacquemart|first24=D.|last25=Jolly|first25=A.|last26=Lamouroux|first26=J.|last27=Le Roy|first27=R.J.|last28=Li|first28=G.|last29=Long|first29=D.A. |last30=Lyulin|first30=O.M.|last31=Mackie|first31=C.J.|last32=Massie|first32=S.T.|last33=Mikhailenko|first33=S.|last34=Müller|first34=H.S.P.|last35=Naumenko|first35=O.V.|last36=Nikitin|first36=A.V.|last37=Orphal|first37=J.|last38=Perevalov|first38=V.|last39=Perrin|first39=A.|last40=Polovtseva|first40=E.R.|last41=Richard|first41=C.|last42=Smith|first42=M.A.H.|last43=Starikova|first43=E.|last44=Sung|first44=K.|last45=Tashkun|first45=S.|last46=Tennyson|first46=J.|last47=Toon|first47=G.C.|last48=Tyuterev|first48=Vl.G.|last49=Wagner|first49=G. |title=The HITRAN2012 molecular spectroscopic database |journal=Journal of Quantitative Spectroscopy and Radiative Transfer |volume=130 |year=2013 |pages=4–50 |issn=0022-4073 |doi=10.1016/j.jqsrt.2013.07.002 |display-authors=29 |bibcode=2013JQSRT.130....4R|url=https://scholarworks.wm.edu/aspubs/114}}</ref> and are thus used to identify the atomic and molecular components of [[star]]s and [[planet]]s, which would otherwise be impossible.