| 词条 | Comet IRAS–Araki–Alcock | ||
| 释义 |
| name=Comet IRAS–Araki–Alcock | background = #FFE0C2 | image =Comet_IRAS-Araki-Alcock_by_Russell_E_Milton.jpg | caption=May 11, 1983 ~6 UT | discoverer= | discovery_date= | orbit_ref =[1] | epoch=1983-May-13 (2445467.5) | semimajor=98.0219089 | perihelion=0.9913410 | aphelion=195.0524769[1] | eccentricity=0.9898865 | inclination=73.2513669 | period=970.49 years | mean_anomaly= | asc_node= | arg_peri= | tjup= | moid={{convert|0.00583|AU|km mi|abbr=on|lk=off}} | dimensions=9.2 km in diameter[3] | albedo= 0.02[3] | abs_magnitude = 12.599[3] }} Comet IRAS–Araki–Alcock (formal designation C/1983 H1, formerly 1983 VII) is a long-period comet that, in 1983, made the closest approach to Earth, about {{convert|0.0312|AU|km mi|abbr=on|lk=on}}, of any comet in 200 years; only Lexell's Comet, in 1770, and 55P/Tempel-Tuttle, in 1366, are thought to have come closer.[7] (The small comet P/1999 J6 (SOHO) passed about {{convert|0.012|AU|km mi|abbr=on|lk=off}} from Earth on 1999-Jun-12.[8] and a small fragment of 252P/LINEAR called P/2016 BA14 passed at a distance of {{convert|0.0237|AU|km mi|abbr=on|lk=off}} on 22 March 2016[1]) The comet was named after its discoverers – the Infrared Astronomical Satellite and two amateur astronomers, George Alcock of the United Kingdom and Genichi Araki of Japan (both men were schoolteachers by profession, although Alcock was retired). Alcock had made his discovery simply by observing through the window of his home, using binoculars.[2][3] During the closest approach the comet appeared as a circular cloud about the size of the full moon, having no discernible tail, and shining at a naked eye magnitude of 3-4. It swept across the sky at an incredible speed of some 30 degrees per day. It is a long-period comet, with an orbital period of around 970 years,[1] and is the parent comet of the minor Eta Lyrid meteor shower.[4] This shower's radiant lies between Vega and Cygnus and produces 1 or 2 meteors an hour in mid-May with a peak between May 9 and May 11. Flyby comparisonComet IRAS–Araki–Alcock is thought to have made the closest approach to Earth in 1983, about {{convert|0.0312|AU|km mi|abbr=on|lk=on}}. This would make it he closest approach up to that time of any comet in 200 years; only Lexell's Comet, in 1770, and 55P/Tempel-Tuttle, in 1366, are thought to have come closer.[7] The small comet P/1999 J6 (SOHO) passed about {{convert|0.012|AU|km mi|abbr=on|lk=off}} from Earth on 1999-Jun-12.[8] and what was though to be a small fragment of 252P/LINEAR called P/2016 BA14 passed at a distance of {{convert|0.0237|AU|km mi|abbr=on|lk=off}} on 22 March 2016[5] However, when observed during its flyby it BA14 was much larger than expected, going from over 100 meters to 1 km in size estimate and one reason for this it was found to be extremely dark. The comet BA14 was calculated to have reflected only 2-3 percent of visible light, based on observations with the NASA Infrared Telescope Facility (a ground-based optical infrared telescope).[6] Flyby Distance comparison:
1983 Flyby
See also
References1. ^{{cite web|url=http://neo.jpl.nasa.gov/ca/ |title=Archived copy |accessdate=March 4, 2014 |deadurl=yes |archiveurl=https://web.archive.org/web/20140307125729/http://neo.jpl.nasa.gov/ca/ |archivedate=March 7, 2014 }} [7][8][9][10]2. ^'Obituary of George Alcock' BBC News, 21-12/2000 3. ^'Outbreak of Comet Fever', TIME Magazine, 23-05-83. "I've discovered a wonderful star," commented Araki, "Now I've got to discover a wonderful wife." 4. ^'Eta Lyrids', Meteor Showers Online, accessed 21-11-08 5. ^{{cite web|url=http://neo.jpl.nasa.gov/ca/ |title=Archived copy |accessdate=March 4, 2014 |deadurl=yes |archiveurl=https://web.archive.org/web/20140307125729/http://neo.jpl.nasa.gov/ca/ |archivedate=March 7, 2014 }} 6. ^ 7. ^1 2 {{cite web |type=1983-10-04 last obs (arc=160 days) |title=JPL Close-Approach Data: C/1983 H1 (IRAS-Araki-Alcock) |url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1983H1;cad=1#cad |accessdate=2012-06-28}} 8. ^1 2 3 {{cite web |type=1983-10-04 last obs (arc=160 days) |title=JPL Orbital Elements: C/1983 H1 (IRAS-Araki-Alcock) |url=https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1983H1;cad=1;old=0;orb=0;cov=0;log=0#elem |accessdate=2012-06-28}} 9. ^1 2 3 {{cite web |type=1983-10-04 last obs (arc=160 days) |title=JPL Orbital Elements: C/1983 H1 (IRAS-Araki-Alcock) |url=https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1983H1;cad=1;old=0;orb=0;cov=0;log=0#phys_par |accessdate=2012-06-28}} 10. ^1 2 {{cite web |type=2010-04-22 last obs (arc=10.9 yr; JFC) |title=JPL Close-Approach Data: P/1999 J6 (SOHO) |url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1999J6;cad=1#cad |accessdate=2012-06-28}} }} {{DEFAULTSORT:Iras-Araki-Alcock, 1983 H1}}{{comet-stub}} 6 : Periodic comets|Jupiter-family comets|Near-Earth objects|Discoveries by IRAS|IRAS catalogue objects|Astronomical objects discovered in 1983 |
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