View source for C/1961 R1 (Humason)

{{Short description|Non-periodic comet}}
{{distinguish|text=another long-period comet with the same name: [[C/1960 M1 (Humason)]]}}
{{Infobox Comet
| name            = C/1961 R1 (Humason)
| image           = Comet Humason (Palomar) September 4, 1962.jpg
| caption         = Comet Humason photographed from the [[Palomar Observatory]] on 4 September 1962
| discoverer      = [[Milton L. Humason]]
| discovery_date  = 1 September 1961
| designations    = 1961e<br>1962 VIII
| orbit_ref       = {{r|jpldata}}
| epoch           = 12 May 1963 ([[Julian day|JD]] 2438161.5)
| observation_arc = 1,517 days (4.15 years)
| obs             = 80
| perihelion      = 2.133 AU
| aphelion        = 408.71 AU
| semimajor       = 205.42 AU
| eccentricity    = 0.98961
| period          = 2,883 years (inbound)<br/> 2,516 years (outbound)
| inclination     = 153.278°
| asc_node        = 155.439°
| arg_peri        = 233.562°
| tjup            = –1.588
| Earth_moid      = 1.2247 AU
| Jupiter_moid    = 1.0725 AU 
| physical_ref    = {{r|Irish_1964|Kidger_1997}}
| dimensions      = {{cvt|30|–|41|km|mi}}
| M1              = 1.35–3.5
| M2              = 10.1
| magnitude       = 
| last_p          = 10 December 1962
| next_p          = 
}}

'''Comet Humason''', [[Astronomical naming conventions#Comets|formally designated]] '''C/1961 R1''' (a.k.a. '''1962 VIII''' and '''1961e'''), was a [[List of non-periodic comets|non-periodic]] [[comet]] discovered by [[Milton L. Humason]] on 1 September 1961. Its [[perihelion]] was well beyond the orbit of [[Mars]], at 2.133 [[Astronomical unit|AU]]. The outbound orbital period is about 2,516 years.

== Physical properties ==
It was a "giant" comet, much more active than a normal comet for its distance to the [[Sun]], with an [[Absolute magnitude#Cometary magnitudes|absolute magnitude]] of 1.35−3.5,{{r|Kidger_1997}} and a [[comet nucleus|nucleus]] diameter estimated at {{cvt|30|–|40|km|mi}}.{{r|Irish_1964}} It could have been up to a hundred times brighter than an average new comet. It had an unusually disrupted or "turbulent" appearance.{{r|Brandt_2004}} It was also unusual in that the spectrum of its tail showed a strong predominance of the ion [[carbon monoxide|CO]]<sup>+</sup>, a result previously seen unambiguously only in [[Comet Morehouse|C/1908 R1 (Morehouse)]].{{r|Huebner_1990}}

== See also ==
* [[C/1729 P1 (Sarabat)]]
* [[Comet Hale–Bopp|C/1995 O1 (Hale–Bopp)]]
* [[C/2014 UN271|C/{{mp|2014 UN|271}} (Bernardinelli–Bernstein)]]

== References ==
<references>
<ref name="Brandt_2004">{{cite book
| author1= J. C. Brandt
| author2= R. D. Chapman
| title= Introduction to Comets
| url= https://books.google.com/books?id=CcSUeymd-14C&pg=PA156
| publisher= [[Cambridge University Press]]
| year= 2004
| page= 156
| isbn= 978-0-521-00466-4 }}
</ref>

<ref name="Huebner_1990">{{cite book
| author1= W. F. Huebner
| title= Physics and Chemistry of Comets
| url= https://books.google.com/books?id=KJnvAAAAMAAJ
| publisher= [[Springer-Verlag]]
| year= 1990
| page= 246
| isbn= 978-0-387-51228-0
| issn= 0941-7834 }}
</ref>

<ref name="Irish_1964">{{cite journal
| title= Comets: Comet Humason 1961e
| url= https://ui.adsabs.harvard.edu/link_gateway/1964IrAJ....6Q.191./ADS_PDF
| journal= [[Irish Astronomical Journal]]
| volume= 6
| pages= 191
| year= 1964
| bibcode= 1964IrAJ....6Q.191. }}
</ref>

<ref name="jpldata">{{cite web
|title= C/1961 R1 – JPL Small-Body Database Lookup
| url= https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1961R1
| website= ssd.jpl.nasa.gov
| publisher= [[Jet Propulsion Laboratory]]
| access-date= 29 May 2019 }}
</ref>

<ref name="Kidger_1997">{{cite web
| author1= M. R. Kidger
| title= Comet Hale–Bopp Light Curve
| url= http://www2.jpl.nasa.gov/comet/news66.html
| website= jpl.nasa.gov
| publisher= [[NASA]] / [[Jet Propulsion Laboratory|JPL]]
| date= 3 April 1997
| access-date= 10 January 2025
| archive-date= 7 April 2023
| archive-url= https://web.archive.org/web/20230407204015/https://www2.jpl.nasa.gov/comet/news66.html
| url-status= dead }}
</ref>
</references>

== External links ==
{{Commons category}}
* {{JPL Small Body|id=1001111}}

{{Comets}}
{{Authority control}}

{{DEFAULTSORT:Humason, 1961 R1}}
[[Category:Non-periodic comets]]
[[Category:1961 in science]]
[[Category:Astronomical objects discovered in 1961]]

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