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
1962 VIII
| orbit_ref = {{r|jpldata}}
| epoch = 12 May 1963 (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)
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, formally designated C/1961 R1 (a.k.a. 1962 VIII and 1961e), was a non-periodic comet discovered by Milton L. Humason on 1 September 1961. Its perihelion was well beyond the orbit of Mars, at 2.133 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 of 1.35−3.5,{{r|Kidger_1997}} and a 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 CO+, a result previously seen unambiguously only in C/1908 R1 (Morehouse).{{r|Huebner_1990}}
See also
References
{{reflist|refs=
| 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 }}
| 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 }}
| 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. }}
|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 }}
| author1= M. R. Kidger
| title= Comet Hale–Bopp Light Curve
| url= http://www2.jpl.nasa.gov/comet/news66.html
| website= jpl.nasa.gov
| 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 }}
}}
External links
{{Commons category}}
- {{JPL Small Body|id=1001111}}
{{Comets}}
{{Authority control}}
{{DEFAULTSORT:Humason, 1961 R1}}
Category:Astronomical objects discovered in 1961
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