Editing Carl Wilhelm Wirtz

{{Short description|German astronomer (1876–1939)}}
{{Infobox scientist
|name              = Carl Wilhelm Wirtz
|image             = Carl W. Wirtz.png
|image_size        = 175
|caption           = Carl Wirtz in 1904
|birth_date        = {{birth date|1876|08|24|df=y}}
|birth_place       = [[Krefeld]], Germany
|death_date        = {{death date and age|1939|02|18|1876|08|24|df=y}}
|death_place       = [[Hamburg]], Germany
|nationality       = [[Germany|German]]
|ethnicity         =
|field             = [[astronomy]]
|work_institutions =
|alma_mater        =
|doctoral_advisor  =
|doctoral_students =
|known_for         = [[spiral nebula]]e, [[redshift]]
|influences        =
|influenced        =
|prizes            =
|religion          =
|signature         =
}}

'''Carl Wilhelm Wirtz''' (24 August 1876 in [[Krefeld]] – 18 February 1939 in [[Hamburg]]) was an [[astronomer]] who studied astronomy at [[Bonn University]] (1895-1898) obtaining his doctorate there <ref name="Joeveer-2007" /> after which he spent his time between the Kiel Observatory {{Obscode|526}} in Germany and the [[Observatory of Strasbourg]], France. He is known for statistically showing the existence of a [[redshift]]-distance correlation for [[spiral galaxies]].<ref name="MPC-Asteroid-Carlwirtz" />

== Scientific career ==

As already [[Vesto Slipher]] in 1912,<ref name="Kragh-2003" /> Wirtz in 1918 observed a systematic [[redshift]] of [[spiral nebula]]e, which was difficult to interpret in terms of a [[physical cosmology|cosmological model]] in which the [[Universe]] is filled more or less uniformly with [[star]]s and [[nebula|nebulae]]. Wirtz additionally used the equivalent in German of ''[[K correction]]''. The term continues to be used in present-day observational cosmology, but Wirtz's observational evidence that the [[Universe]] is expanding is not often mentioned.<ref name="Kinney-1996" /> He wrote:<ref name="Wirtz-1918" />

{{Quote|1=It is remarkable, that our system of fixed stars shall have such a very strong displacement of 820 km/s, and equally strange is the interpretation of the systematic constant k = + 656 km. If we ascribe a verbatim interpretation to this value, then this means that the system of spiral nebulae is drifting apart by a velocity of 656 km with respect to the momentary location of the solar system as the center.}}

In 1922,<ref name="van den Bergh-2011" /> he wrote a paper where he argued that the observational results suggest, that the redshifts of distant galaxies are becoming higher than more closer ones, which he interpreted as an increase of their radial velocities with distance, and that larger masses have smaller redshifts than smaller ones.<ref name="Wirtz-1922" /> In another note of the same year, he argued that counter-clockwise spiraling galaxies have smaller redshifts than clockwise spiraling ones.<ref name="Wirtz-1922b" /> In 1924 he obtained more precise results, and interpreted them both as a confirmation of an increase of radial velocities with distance, but also as confirmation of a [[de Sitter universe]], in which the increase of redshift is seen as caused by an increased [[time dilation]] in distant parts of the universe.<ref name="Wirtz-1924" />

In 1936, Wirtz wrote a short paper alluding to the priority for his 1922-conclusion that the radial velocities of galaxies are increasing with their distance.<ref name="Wirtz-1936" />

== Honors ==
Mars-crossing asteroid [[26074 Carlwirtz]] and the Martian crater ''[[Wirtz (crater)|Wirtz]]'' were named after him.<ref name="MPC-Asteroid-Carlwirtz" /><ref>{{GPN|6564|name=Martian Crater Wirtz}}</ref><ref name="JPL-catalog" />

== See also ==
* [[Hubble's law]]

== References ==
{{reflist|refs=

<ref name="Joeveer-2007">{{cite book
 |last1=Joeveer |first1=M.
 |chapter=Wirtz, Carl Wilhelm
 |year=2007
 |title=The Biographical Encyclopedia of Astronomers
 |journal=[[The Bibliographical Encyclopedia of Astronomers]]
 |pages=1233
 |isbn=978-0-387-30400-7
 |doi=10.1007/978-0-387-30400-7_1491
 |chapter-url=https://doi.org/10.1007/978-0-387-30400-7_1491
 }}</ref>

<ref name="Kragh-2003">{{cite journal
 |last1=Kragh |first1=H.
 |last2=Smith |first2=R. W.
 |year=2003
 |title=Who discovered the expanding universe
 |journal=[[History of Science (journal)|History of Science]]
 |volume=41 |issue=2
 |pages=141–62
 |bibcode=2003HisSc..41..141K
 |doi=10.1177/007327530304100202|s2cid=119368912
 }}</ref>

<ref name="Kinney-1996">{{cite journal
 | last1=Kinney  | first1=A. C.
 | last2=Calzetti | first2=D.|author2-link= Daniela Calzetti
 | last3=Bohlin | first3=R. C.
 | last4=McQuade | first4=K.
 | last5=Storchi-Bergmann | first5=T.
 | last6=Schmitt | first6=H. R. 
 | year=1996
 | title=Template ultraviolet spectra to near-infrared spectra of star-forming galaxies and their application to K-corrections
 | journal=[[The Astrophysical Journal]]
 | volume=467 | pages=38–60
 | bibcode=1996ApJ...467...38K
 | doi=10.1086/177583| hdl=10183/108772
 | url=http://www.lume.ufrgs.br/bitstream/10183/108772/1/000177101.pdf
 | hdl-access=free
 }}</ref>

<ref name="Wirtz-1918">{{cite journal
 |last1=Wirtz |first1=C. W.
 |year=1918
 |title=Über die Bewegungen der Nebelflecke. Vierte Mitteilung
 |journal=[[Astronomische Nachrichten]]
 |volume=206 |issue=4933 |pages=109–112
 |bibcode=1918AN....206..109W
 |doi=10.1002/asna.19182061302|url=https://zenodo.org/record/1424916
 }}</ref>

<ref name="van den Bergh-2011">{{cite journal
 |last1=van den Bergh |first1=Sidney 
 |year=2011
 |title=Discovery of the Expansion of the Universe
 |journal=Journal of the Royal Astronomical Society of Canada 
 |volume=105 
 |issue=5 
 |page=197 
 |arxiv=1108.0709|bibcode=2011JRASC.105..197V 
 }}</ref>

<ref name="Wirtz-1922">{{Cite journal
  |last1=Wirtz |first1=C. W.
  |date       = April 1922
  |title      = Einiges zur Statistik der Radialbewegungen von Spiralnebeln und Kugelsternhaufen
  |journal    = Astronomische Nachrichten
  |volume     = 215; Page 349 (AN Homepage)
  |issue=17
 |pages=349–354
 |bibcode    = 1922AN....215..349W
  |doi        = 10.1002/asna.19212151703|url=https://zenodo.org/record/1424934
 }}</ref>

<ref name="Wirtz-1922b">{{cite journal
 |last1=Wirtz |first1=C. W.
 |year=1922
 |title=Notiz zur Radialbewegung der Spiralnebel
 |journal=[[Astronomische Nachrichten]]
 |volume=215 |issue=5184 |pages=451
 |bibcode=1922AN....215..451H
 |doi = 10.1002/asna.19212152304|url=https://zenodo.org/record/1424936
 }}</ref>

<ref name="Wirtz-1924">{{cite journal
 |last1=Wirtz |first1=C. W.
 |year=1924
 |title=De Sitters Kosmologie und die Radialbewegungen der Spiralnebel
 |journal=[[Astronomische Nachrichten]]
 |volume=222|issue=5306|pages=21–26
 |bibcode=1924AN....222...21W
 |doi=10.1002/asna.19242220203}}</ref>

<ref name="Wirtz-1936">{{cite journal
 |last1=Wirtz |first1=C. W.
 |year=1936
 |title=Ein literarischer Hinweis zur Radialbewegung der Spiralnebel
 |journal=[[Zeitschrift für Astrophysik]]
 |volume=11 |pages=261
 |bibcode=1936ZA.....11..261W}}</ref>

<ref name="JPL-catalog">{{cite web
 | title=PIA08746: Dunes of Wirtz | date=September 10, 2006
 | publisher=Jet Propulsion Laboratory
 | url=https://photojournal.jpl.nasa.gov/catalog/PIA08746
 | access-date=2017-11-06 }}</ref>

<ref name="MPC-Asteroid-Carlwirtz">{{cite web
  |title      = 26074 Carlwirtz (1977 TD)
  |work       = [[Minor Planet Center]]
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=26074
  |access-date = 19 February 2019}}</ref>

}} <!-- end of reflist -->

== External links ==
* [http://www.klima-luft.de/steinicke/ngcic/persons/wirtz.htm Carl Wilhelm Wirtz], www.klima-luft.de
* [http://adsabs.harvard.edu/full/1999ASPC..167..237S Carl Wilhelm Wirtz – Pioneer in Cosmic Dimensions],  W. C. Seitter, & H. W. Duerbeck (1999)
* [http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?db_key=AST&author=wirtz,%20c.&aut_syn=NO Carl Wilhelm Wirtz] @ [[Astrophysics Data System]]
 
{{Use dmy dates|date=February 2019}}
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[[Category:20th-century German astronomers]]
[[Category:1876 births]]
[[Category:1939 deaths]]
[[Category:People from Krefeld]]
[[Category:Academic staff of the University of Strasbourg]]
[[Category:Recipients of the Lalande Prize]]