Editing Redshift (section)

===Local observations===
In nearby objects (within our [[Milky Way]] galaxy) observed redshifts are almost always related to the [[Line-of-sight propagation|line-of-sight]] velocities associated with the objects being observed. Observations of such redshifts and blueshifts enable astronomers to measure [[velocity|velocities]] and parametrize the [[mass]]es of the [[orbit]]ing [[star]]s in [[spectroscopic binaries]]. Similarly, small redshifts and blueshifts detected in the spectroscopic measurements of individual stars are one way astronomers have been able to [[Methods of detecting exoplanets#Radial velocity|diagnose and measure]] the presence and characteristics of [[Exoplanet|planetary systems]] around other stars and have even made very [[Rossiter–McLaughlin effect|detailed differential measurements]] of redshifts during [[Methods of detecting exoplanets|planetary transits]] to determine precise orbital parameters. Some approaches are able to track the redshift variations in multiple objects at once.<ref>{{cite journal |last1=Ge |first1=Jian |last2=Van Eyken |first2=Julian |last3=Mahadevan |first3=Suvrath |author3-link=Suvrath Mahadevan |last4=Dewitt |first4=Curtis |last5=Kane |first5=Stephen R. |last6=Cohen |first6=Roger |last7=Vanden Heuvel |first7=Andrew |last8=Fleming |first8=Scott W. |last9=Guo |first9=Pengcheng |last10=Henry |first10=Gregory W. |last11=Schneider |first11=Donald P. |last12=Ramsey |first12=Lawrence W. |last13=Wittenmyer |first13=Robert A. |last14=Endl |first14=Michael |last15=Cochran |first15=William D. |display-authors=4 |date=2006 |title=The First Extrasolar Planet Discovered with a New-Generation High-Throughput Doppler Instrument |journal=The Astrophysical Journal |volume=648 |issue=1 |pages=683–695 |arxiv=astro-ph/0605247 |bibcode=2006ApJ...648..683G |doi=10.1086/505699 |s2cid=13879217 |last16=Ford |first16=Eric B. |last17=Martin |first17=Eduardo L. |last18=Israelian |first18=Garik |last19=Valenti |first19=Jeff |last20=Montes |first20=David}}</ref> 

Finely detailed measurements of redshifts are used in [[helioseismology]] to determine the precise movements of the [[photosphere]] of the [[Sun]].<ref>{{cite journal | doi = 10.1007/BF00243557 | title = Solar and stellar seismology | date = 1988 | last1 = Libbrecht | first1 = Keng | journal = Space Science Reviews | volume = 47 | issue = 3–4 |bibcode=1988SSRv...47..275L | pages=275–301| s2cid = 120897051 | url = https://authors.library.caltech.edu/104214/1/1988SSRv___47__275L.pdf }}</ref> Redshifts have also been used to make the first measurements of the [[rotation]] rates of [[planet]]s,<ref>In 1871 [[Hermann Carl Vogel]] measured the rotation rate of [[Venus]]. [[Vesto Slipher]] was working on such measurements when he turned his attention to spiral nebulae.</ref> velocities of [[interstellar cloud]]s,<ref>An early review by [[Jan Hendrik Oort|Oort, J. H.]] on the subject: {{cite journal | title=The formation of galaxies and the origin of the high-velocity hydrogen | journal=[[Astronomy and Astrophysics]] | volume=7 | page=381 | date=1970 | bibcode=1970A&A.....7..381O | last= Oort | first= J. H. }}</ref> the [[Galaxy rotation curve|rotation of galaxies]],<ref name="basicastronomy" /> and the [[dynamics (mechanics)|dynamics]] of [[Accretion disk|accretion]] onto [[neutron star]]s and [[black hole]]s which exhibit both Doppler and gravitational redshifts.<ref>{{cite journal| last=Asaoka | first=Ikuko | bibcode=1989PASJ...41..763A | title=X-ray spectra at infinity from a relativistic accretion disk around a Kerr black hole | journal=Publications of the Astronomical Society of Japan | volume=41 | issue=4 | date=1989 | pages=763–778 }}</ref> The [[temperature]]s of various emitting and absorbing objects can be obtained by measuring [[Doppler broadening]]—effectively redshifts and blueshifts over a single emission or absorption line.<ref>{{cite book | last1=Rybicki | first1=G. B. | first2=A. R. | last2=Lightman | title=Radiative Processes in Astrophysics | publisher=John Wiley & Sons | year=1979 | page=288 | isbn=0-471-82759-2 }}</ref> By measuring the broadening and shifts of the 21-centimeter [[hydrogen line]] in different directions, astronomers have been able to measure the [[Recessional velocity|recessional velocities]] of [[interstellar gas]], which in turn reveals the [[rotation curve]] of our Milky Way.<ref name=basicastronomy/> Similar measurements have been performed on other galaxies, such as [[Andromeda Galaxy|Andromeda]].<ref name=basicastronomy/> As a diagnostic tool, redshift measurements are one of the most important [[astronomical spectroscopy|spectroscopic measurements]] made in astronomy.