View source for 171P/Spahr

{{Short description|Periodic comet with 6 year orbit}}
{{Infobox Comet
| name=171P/Spahr
| image= 171P_2019-01-24_image_ZTF-sso-559-zr-fov-3.5arcmin.png
| discoverer=[[Timothy B. Spahr]]
| discovery_date=November 16, 1998
| designations=P/1998 W1<br />P/2005 R3
| epoch=2012-Feb-03<br />([[Julian day|JD]] 2455960.5)
| semimajor=3.553 AU
| perihelion=1.764 AU
| aphelion=5.342 [[Astronomical Unit|AU]]
| eccentricity=0.5033
| period=6.70 [[Julian year (astronomy)|a]]
| inclination= 21.94°
| last_p=January 13, 2019<ref name="NK2169"/><br />April 30, 2012<ref name="NK2169"/><br />September 3, 2005
| next_p=2025-Sep-25<ref name=MPC>{{mpc|171p}}</ref>
}}

'''171P/Spahr''' is a [[List of periodic comets|periodic]] [[comet]] in the [[Solar System]]. 171P/Spahr  was recovered on 20–24 October 2011 at [[apparent magnitude]] 20.6 using the {{convert|2.0|m|in|adj=on}} [[Faulkes Telescope South]].<ref name="Remanzacco"/> 171P/Spahr is peaked at about magnitude 18 in 2012.<ref name="Yoshida-171p"/>

During the 1999 passage the comet brightened to about magnitude 13.5.<ref name=kronk/>

At perihelion on January 13, 2019 when the comet was 1[[Astronomical Unit|AU]] from Earth, the [[3-sigma]] uncertainty in the comet's Earth distance was ±500&nbsp;km.

== References ==
{{reflist|refs=

<ref name="Remanzacco">{{cite web
  |date=October 28, 2011
  |title=Recovery of comet 171P/Spahr 
  |publisher=Remanzacco Observatory in Italy – Comets & Neo
  |author=Ernesto Guido
  |author2=Giovanni Sostero
  |author2-link=Giovanni Sostero
  |author3=Nick Howes
  |author3-link=Nick Howes
  |author4=Antoni Kasprzyk
  |name-list-style=amp 
  |url=http://remanzacco.blogspot.com/2011/10/recovery-of-comet-171pspahr.html
  |accessdate=2011-11-01}}</ref>

<ref name="Yoshida-171p">{{cite web
  |date=2011-10-30
  |title=171P/Spahr
  |publisher=Seiichi Yoshida's Comet Catalog
  |author=Seiichi Yoshida
  |url=http://www.aerith.net/comet/catalog/0171P/index.html
  |accessdate=2010-03-01}}</ref>

<ref name="NK2169">{{cite web
  |date=2011-11-26
  |title=171P/Spahr (NK 2169)
  |publisher=OAA Computing and Minor Planet Sections
  |author=Syuichi Nakano
  |author-link=Syuichi Nakano
  |url=http://www.oaa.gr.jp/~oaacs/nk/nk2169.htm
  |accessdate=2012-02-20}}</ref>

<ref name=kronk>{{Cite web
 |first       = Gary W.
 |last        = Kronk
 |authorlink  = Gary W. Kronk
 |date        = 2001–2005
 |title       = 171P/Spahr
 |url         = http://cometography.com/pcomets/171p.html
 |accessdate  = 2012-02-27
 |url-status  = dead
 |archiveurl  = https://web.archive.org/web/20010405095745/http://cometography.com/
 |archivedate = 2001-04-05
}}()</ref>

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

== External links ==
* {{JPL Small Body|id=1000239}}
* [http://www.aerith.net/comet/catalog/0171P/index.html 171P/Spahr] – Seiichi Yoshida @ aerith.net
* [https://web.archive.org/web/20160304113154/http://scully.cfa.harvard.edu/cgi-bin/returnprepeph.cgi?d=c&o=0171P Elements and Ephemeris for 171P/Spahr] – [[Minor Planet Center]]
* [https://web.archive.org/web/20080517132528/http://cometography.com/pcomets/171p.html Discovery and Historical Highlights at Gary W. Kronk's Cometography]

{{Comets}}
{{2019 in space}}
{{PeriodicComets Navigator|170P/Christensen|172P/Yeung}}
{{Authority control}}

{{DEFAULTSORT:Spahr, 171P}}
[[Category:Periodic comets]]
[[Category:Jupiter-family comets|171P]]
[[Category:Numbered comets|0171]]
[[Category:Comets in 2019|171P]]


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