774 Armor
{{Use dmy dates|date=October 2019}}
{{Infobox planet
| minorplanet= yes
| background= #D6D6D6
| name= 774 Armor
| mpc_name= (774) Armor
| alt_names= 1913 TW
| discoverer= C. le Morvan
| discovered= 19 December 1913
| discovery_site= Paris
| epoch= 31 July 2016 (JD 2457600.5)
| eccentricity= 0.16914
| semimajor= {{Convert|3.0472|AU|Gm|abbr=on}}
| perihelion= {{Convert|2.5318|AU|Gm|abbr=on}}
| aphelion= {{Convert|3.5625|AU|Gm|abbr=on|lk=on}}
| inclination= 5.5589°
| asc_node= 250.253°
| arg_peri= 28.478°
| mean_anomaly= 240.634°
| mean_motion= {{Deg2DMS|0.18529|sup=ms}} / day
| observation_arc= 107.33 yr (39203 d)
| uncertainty= 0
| abs_magnitude= 8.8
| rotation= {{Convert|25.107|h|d|abbr=on|lk=on}}
| albedo= {{val|0.2529|0.020}}
| mean_radius= {{val|25.185|0.95}} km
| moid= {{Convert|1.51688|AU|Gm|abbr=on}}
| jupiter_moid= {{Convert|1.56651|AU|Gm|abbr=on}}
| tisserand= 3.209
}}
774 Armor is a minor planet (specifically an asteroid) orbiting in the main belt. It was discovered on 13 December 1913, in Paris by French astronomer Charles le Morvan and was named after the Celtic region of Armorica. The asteroid is orbiting at a distance of {{val|3.05|ul=AU}} with a period of {{Convert|1942.9|days|years|2|disp=out}} and an eccentricity of 0.169. The orbital plane is inclined by an angle of 5.56° to the plane of the ecliptic.
In the SMASS-I taxonomy, this is classified as an S-type asteroid. It spans a girth of approximately 50 km. The rotation of this asteroid is commensurate with the length of an Earth day, requiring measurements from more than one latitude for full coverage. Photometric observations from the US and Australia in 2012 provided an estimated rotation period of {{val|25.107|0.005|u=hours}} with a brightness variation of {{val|0.16|0.02}} in magnitude. This is consistent with the results of an earlier study in 2006.
References
{{Reflist|refs=
| title=Lightcurve Analsyis of 774 Armor and 3161 Beadell
| display-authors=1 | last1=Oey | first1=Julian
| last2=Han | first2=Xianming L. | last3=Gipson | first3=Kevin
| journal=Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers
| volume=40 | issue=2 | page=64 | date=April 2013
| bibcode=2013MPBu...40...64O | postscript=. }}
| title=Dictionary of Minor Planet Names
| first=Lutz D. | last=Schmadel | year=2012
| page=72 | isbn=9783642297182 | postscript=.
| publisher=Springer Berlin Heidelberg
| url=https://books.google.com/books?id=aeAg1X7afOoC&pg=PA72 }}
| url=https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=774
| title=774 Armor (1913 TW)
| work=JPL Small-Body Database
| publisher=NASA/Jet Propulsion Laboratory
| access-date=5 May 2016 }}
| title=Small Main-Belt Asteroid Spectroscopic Survey in the Near-Infrared
| last1=Burbine | first1=Thomas H. | last2=Binzel | first2=Richard P.
| journal=Icarus | postscript=.
| volume=159 | issue=2 | pages=468–499 | date=October 2002
| doi=10.1006/icar.2002.6902 | bibcode=2002Icar..159..468B }}
}}
External links
- [http://www.minorplanetobserver.com/pdolc/A774_2006.HTM Lightcurve plot of 774 Armor], Palmer Divide Observatory, B. D. Warner (2006)
- [http://www.minorplanet.info/PHP/lcdbsummaryquery.php Asteroid Lightcurve Database (LCDB)], query form ([http://www.minorplanet.info/lightcurvedatabase.html info] {{Webarchive|url=https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html |date=16 December 2017 }})
- [https://books.google.com/books?id=aeAg1X7afOoC Dictionary of Minor Planet Names], Google books
- [http://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève, Raoul Behrend
- [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
- {{AstDys|774}}
- {{JPL small body}}
{{Minor planets navigator |773 Irmintraud |number=774 |775 Lumière}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Armor}}
Category:S-type asteroids (SMASS)
Category:Discoveries by C. le Morvan
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