View source for C/1989 Y1 (Skorichenko–George)

{{short description|Non-periodic comet}}
{{Infobox comet
| name            = C/1989 Y1 (Skorichenko–George)
| image           = 
| caption         = 
| discovery_ref   = {{r|IAUC_4925|IAUC_4929}}
| discoverer      = Boris Skoritchenko<br>Douglas B. George
| discovery_date  = 17 December 1989
| designations    = 1990 VI<br>1989e<sub>1</sub>
| orbit_ref       = {{r|jpl|barycenter}}
| epoch           = 24 February 1990 ([[Julian day|JD]] 2447946.5)
| observation_arc = 1,008 days (2.76 years)
| obs             = 106
| aphelion        = 1,188.42 AU
| perihelion      = 1.569 AU
| semimajor       = 594.994 AU
| eccentricity    = 0.997363
| period          = 14,514 years
| inclination     = 59.3660
| asc_node        = 279.998°
| arg_peri        = 137.862°
| tjup            = 
| Earth_moid      = 0.7346 AU
| Jupiter_moid    = 1.8047 AU
| physical_ref    = {{r|jpl}}
| M1              = 5.3
| M2              = 11.9
| magnitude       = 9–10<br><small>(1990 apparition)</small>
| last_p          = 11 April 1990
| next_p          = 
}}

'''Comet Skorichenko–George''' (sometimes spelled '''Scorichenko–George'''), formally designated as '''C/1989 Y1''', '''1990 VI''', and '''1989e<sub>1</sub>''', is a non-periodic [[comet]] co-discovered by astronomers Boris Skorichenko and Doug George on December 17, 1989. It has a hyperbolic trajectory around the Sun,{{r|jpl}} but still weakly bound to it by its barycenter.{{r|barycenter}}

== Discovery and observations ==
It was discovered on December 17, 1989 by Doug George of [[Kanata, Ontario|Kanata]] (near [[Ottawa]]), [[Ontario]], [[Canada]], and [[Soviet Union|Soviet]] astronomer Boris Skoritchenko ([[Mezmay]], [[Krasnodar Krai]]). Skoritchenko was using 8×20 [[binoculars]],{{r|Korneyev_2005}} whilst George was using a 16" reflector and had searched for 65 hours{{r|Machholz_1990}}. The comet was [[Apparent magnitude|magnitude]] 10.5 in the northern evening sky. It passed its [[perihelion]] on April 11, 1990 at a distance of {{convert|1.57|AU|e6km|abbr=unit}},{{r|jpl}} and remained visible as a magnitude 9–10 object in the night sky until April 1990

C<sub>2</sub> emission bands were observed in the comet Skorichenko-George. Unlike most comets, Skorichenko–George did not produce a tail.{{r|Machholz_1997}} Its coma remained consistently diffuse, estimated to be around {{cvt|190,000–290,000|km|mi}} in diameter.{{r|Machholz_1997}}

== References ==
{{Reflist|refs=

<ref name="jpl">{{cite web
| title= C/1989 Y1 (Skorichenko–George) – JPL Small-Body Database Lookup
| url= https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1989Y1
| website= ssd.jpl.nasa.gov
| publisher= [[Jet Propulsion Laboratory]]
| access-date= 15 November 2024 }}
</ref>

<ref name="barycenter">{{cite web
| author1= [[JPL Horizons On-Line Ephemeris System|Horizons]] output
| url= http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=C/1989+Y1
| title= Barycentric Osculating Orbital Elements for Comet C/1989 Y1 (Skorichenko-George)
| access-date= 4 February 2011 }} (Solution using the Solar System [[Center of mass#Barycenter in astrophysics and astronomy|Barycenter]] and [[Barycentric coordinates (astronomy)|barycentric coordinates]]. Select Ephemeris Type:Elements and Center:@0)
</ref>

<ref name="IAUC_4925">{{cite journal
| author1= D. W. Green
| title= COMET GEORGE (1989e1)
| url= http://www.cbat.eps.harvard.edu/iauc/04900/04925.html
| journal= Central Bureau for Astronomical Telegrams
| date= 19 December 1989
| volume= 4925
| bibcode= 1989IAUC.4925....1G }}
</ref>

<ref name="IAUC_4929">{{cite journal
| author1= D. W. Green
| title= COMET SKORICHENKO-GEORGE (1989e1)
| url= http://www.cbat.eps.harvard.edu/iauc/04900/04929.html
| journal= Central Bureau for Astronomical Telegrams
| date= 23 December 1989
| volume= 4929
| bibcode= 1989IAUC.4929....1C }}
</ref>

<ref name="Korneyev_2005">{{cite web
| author1= V. Korneyev
| title= C/1989 Y1 (Skorichenko-George)
| url= http://www.kor01.org/893.html
| archive-date= 15 March 2005
| archive-url= https://web.archive.org/web/20050315201749/http://www.kor01.org/893.html
| url-status= dead
| language= ru }}
</ref>

<ref name="Machholz_1990">{{cite news
| author1= D. Machholz
| title= SAC News: Comet Comments
| url= http://www.saguaroastro.org/content/SACNEWS/sac1990/sac.9002.pdf
| newspaper= Saguaro Astronomy Club
| issue= 157
| date= February 1990
| archive-date= 5 January 2011
| archive-url= https://web.archive.org/web/20110105125054/http://www.saguaroastro.org/content/SACNEWS/sac1990/sac.9002.pdf
| url-status= dead }}
</ref>

<ref name="Machholz_1997">{{cite journal
| author1= D. Machholz
| title= The apparition of comet Skorichenko-George (1989e1 {{=}} 1990 VI).
| url= https://ui.adsabs.harvard.edu/link_gateway/1997JALPO..39..177M/ADS_PDF
| journal= Strolling Astronomer
| date= August 1997
| volume= 39
| issue= 4
| pages= 177–189
| bibcode= 1997JALPO..39..177M }}
</ref>

}}

{{Comets}}
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{{DEFAULTSORT:Skorichenko-George, 1989 Y1}}
[[Category:Non-periodic comets]]
[[Category:Hyperbolic comets]]
[[Category:1989 in science]]
[[Category:Astronomical objects discovered in 1989|19891217]]


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