C/1975 V1 (West)

<h2 id="history">History</h2>

It was discovered photographically by <a href="/facts/Richard_M._West/4vFQf3Wu">Richard M. West</a>, of the <a href="/facts/European_Southern_Observatory/mJtjDbwx">European Southern Observatory</a>, on 10 August 1975. The comet came to <a href="/facts/Perihelion/VaL6ow9w">perihelion</a> (closest approach to the Sun) on 25 February 1976.<a class="footnote-ref" id="fnref:2" href="#fn:2">2</a> During perihelion the comet had a minimum solar elongation of 6.4° and as a result of <a href="/facts/Forward_scatter/Rsmc5xCo">forward scattering</a> reached a peak <a href="/facts/Apparent_magnitude/7pCTF1Me">apparent magnitude</a> of −3.<a class="footnote-ref" id="fnref:3" href="#fn:3">3</a> From 25 to 27 February, observers reported that the comet was bright enough to study during full daylight.<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a>
Despite its brightness, Comet West went largely unreported in the popular media. This was partly due to the relatively disappointing display of <a href="/facts/Comet_Kohoutek/VogwfMAL">Comet Kohoutek</a> in 1973, which had been widely predicted to become extremely prominent: scientists were wary of making predictions that might raise public expectations.<a class="footnote-ref" id="fnref:5" href="#fn:5">5</a>
<a href="/facts/The_New_York_Times/T9marWVX">The New York Times</a>, however, reported this about Comet West on 2 March 1976:<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a>

<blockquote>From tomorrow until Sunday a comet that may prove one of the brightest in this decade is expected to reach maximum visibility in the eastern sky before sunrise. ... By Wednesday, <a href="/facts/Brian_G._Marsden/uW2IWGIC">Dr. Marsden</a> believes, it will be far enough from the sun to be visible to the unaided eye— Walter Sullivan, <a href="/facts/The_New_York_Times/T9marWVX">The New York Times</a> (2 March 1976)</blockquote>
<h2 id="period">Period</h2>

With a nearly <a href="/facts/Parabolic_trajectory/vDNtF83E">parabolic trajectory</a>, estimates for the <a href="/facts/Orbital_period/94f56uh2">orbital period</a> of this comet have varied from 254,000<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a> to 558,000 years.<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a> Computing the <a href="/facts/Curve_fitting/zrLKw6Xj">best-fit</a> orbit for this long-period comet is made more difficult since it underwent a <a href="/facts/Comet_nucleus/dpJGJlqw">splitting event</a> which may have caused a non-gravitational <a href="/facts/Perturbation_(astronomy)/og5hPpjQ">perturbation</a> of the orbit. The 2008 <a href="/facts/Smithsonian_Astrophysical_Observatory/1Bz2ApPt">SAO</a> Catalog of Cometary Orbits shows 195 observations for C/1975 V1 and 135 for C/1975 V1-A, for a combined total of 330 (218 observations were used in the fit).

<h2 id="breakup">Breakup</h2>

Before the <a href="/facts/Perihelion/VaL6ow9w">perihelion</a> passage, and using 28 positions obtained between 10 August 1975 and 27 January 1976, Comet West was estimated to have an orbital period of about 254,000 years.<a class="footnote-ref" id="fnref:9" href="#fn:9">9</a> As the comet passed within 30 million km of the Sun, the nucleus was observed to split into four fragments.<a class="footnote-ref" id="fnref:10" href="#fn:10">10</a>
The first report of the split came around 7 March 1976 at 12:30 UTC, when reports were received that the comet had broken into two pieces. Astronomer Steven O'Meara, using the 9-inch Harvard Refractor, reported that two additional fragments had formed on the morning of 18 March.
The fragmentation of the nucleus was, at the time, one of very few comet breakups observed, one of the most notable previous examples being the <a href="/facts/Great_Comet_of_1882/WxBTN6WR">Great Comet of 1882</a>, a member of the <a href="/facts/Kreutz_Sungrazers/DS5MAJ9l">Kreutz Sungrazing</a> 'family' of comets. More recently, comets <a href="/facts/Schwassmann-Wachmann-3/Gc8yd1BH">Schwassmann-Wachmann-3</a> (73P), <a href="/facts/C%2f1999_S4/DlgxxJmS">C/1999 S4</a> LINEAR, and <a href="/facts/57P%2fdu_Toit-Neujmin-Delporte/pmXhQKfM">57P/du Toit-Neujmin-Delporte</a>, have been observed to split or disintegrate during their passage close to the Sun.
The comet has been more than 50 AU (7.5 billion km) from the Sun since 2003.<a class="footnote-ref" id="fnref:11" href="#fn:11">11</a>

<h2 id="nomenclature">Nomenclature</h2>
In the nomenclature of the time, it was known as Comet 1976 VI or Comet 1975n, but the modern nomenclature is C/1975 V1. (Note that "1976 VI" uses the Roman numeral VI = 6, while "C/1975 V1" is the letter V and the number 1).

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/List_of_Solar_System_objects_by_greatest_aphelion/BH3S7Q7E">List of Solar System objects by greatest aphelion</a></li></ul>

<h2 id="external-links">External links</h2>

Wikimedia Commons has media related to Comet West (C/1975 V1).

<ul><li><a href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1001163">C/1975 V1</a> at the <a href="/facts/JPL_Small-Body_Database/YQQLDXng">JPL Small-Body Database</a><ul><li><a href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1001163&view=C">Close approach</a> · <a href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1001163&view=D">Discovery</a> · <a href="https://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=1001163">Ephemeris</a> · <a href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1001163&view=V">Orbit viewer</a> · <a href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1001163&view=O">Orbit parameters</a> · <a href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1001163&view=P">Physical parameters</a></li></ul></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">D. K. Yeomans (April 2007). "Great Comets in History". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 28 December 2007. <a href="https://ssd.jpl.nasa.gov/sb/great_comets.html" target="_blank">https://ssd.jpl.nasa.gov/sb/great_comets.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">"C/1975 V1-A (West) – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 7 August 2011. <a href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1975V1" target="_blank">https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1975V1</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">G. W. Kronk. "C/1975 V1 (West)". Cometography.com. Retrieved 1 February 2011. <a href="http://cometography.com/lcomets/1975v1.html" target="_blank">http://cometography.com/lcomets/1975v1.html</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">G. W. Kronk. "C/1975 V1 (West)". Cometography.com. Retrieved 1 February 2011. <a href="http://cometography.com/lcomets/1975v1.html" target="_blank">http://cometography.com/lcomets/1975v1.html</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">R. Burnham, Jr.; D. H. Levy (2000). Great Comets (1st ed.). Cambridge University Press. p. 73. ISBN 978-0-521-64600-0. <a href="978-0-521-64600-0" target="_blank">978-0-521-64600-0</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">W. Sullivan (2 March 1976). "Comet Expected in Sky for Week". The New York Times. p. 17. Retrieved 16 November 2023. <a href="https://www.nytimes.com/1976/03/02/archives/comet-expected-in-sky-for-week-maximum-visibility-would-be-in-east.html" target="_blank">https://www.nytimes.com/1976/03/02/archives/comet-expected-in-sky-for-week-maximum-visibility-would-be-in-east.html</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">G. W. Kronk. "C/1975 V1 (West)". Cometography.com. Retrieved 1 February 2011. <a href="http://cometography.com/lcomets/1975v1.html" target="_blank">http://cometography.com/lcomets/1975v1.html</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">J. Coffey (21 September 2009). "Comet West". Universe Today. Archived from the original on 20 September 2012. Retrieved 1 February 2011. <a href="https://web.archive.org/web/20120920222133/http://www.universetoday.com/40814/comet-west/" target="_blank">https://web.archive.org/web/20120920222133/http://www.universetoday.com/40814/comet-west/</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">G. W. Kronk. "C/1975 V1 (West)". Cometography.com. Retrieved 1 February 2011. <a href="http://cometography.com/lcomets/1975v1.html" target="_blank">http://cometography.com/lcomets/1975v1.html</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">D. J. Eicher (2013). "Comets of the Modern Era". Comets! Visitors from Deep Space. Cambridge University Press. p. 77. ISBN 978-1-107-62277-7. <a href="978-1-107-62277-7" target="_blank">978-1-107-62277-7</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">Horizons output. "Observer Table for Comet C/1975 V1-A (West)". Retrieved 25 February 2019. (Observer Location:@sun) <a href="/wiki/JPL_Horizons_On-Line_Ephemeris_System" target="_blank">/wiki/JPL_Horizons_On-Line_Ephemeris_System</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
</ol>

C/1975 V1 (West) open-in-new

C/1975 V1 (West)