1345 Potomac
{{Short description|Hildian asteroid}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
| minorplanet = yes
| name = 1345 Potomac
| background = #D6D6D6
| image =
| image_size =
| caption =
| discoverer = J. H. Metcalf
| discovery_site = Taunton Obs.
| discovered = 4 February 1908
| mpc_name = (1345) Potomac
| alt_names = 1908 CG{{·}}1932 CF
1932 EA{{·}}1932 FB
{{mp|1971 DE|2}}
| pronounced =
| named_after = Potomac River
{{nowrap|{{small|(U.S. Mid-Atlantic river)}}}}
| mp_category = main-belt{{·}}{{small|(outer)}}
{{nowrap|Hilda{{·}}background}}
| epoch = 27 April 2019 (JD 2458600.5)
| uncertainty = 0
| observation_arc = 111.20 yr (40,617 d)
| aphelion = 4.7100 AU
| perihelion = 3.2611 AU
| semimajor = 3.9856 AU
| eccentricity = 0.1818
| period = 7.96 yr (2,906 d)
| mean_anomaly = 31.380°
| mean_motion = {{Deg2DMS|0.1239|sup=ms}} / day
| inclination = 11.402°
| asc_node = 137.43°
| arg_peri = 333.12°
| jupiter_moid = 0.4592 AU
| tisserand = 2.9930
| mean_diameter = {{val|71.82|3.0|ul=km}}
{{val|72.975|0.463|u=km}}
{{val|76.72|2.34|u=km}}
| rotation = {{val|11.41|0.01|ul=h}}
| albedo = {{val|0.039|0.003}}
{{val|0.043|0.008}}
{{val|0.0439|0.004}}
| spectral_type = Tholen {{=}} X{{·}}C
B–V {{=}} 0.719
U–B {{=}} 0.286
}}
1345 Potomac ({{IPAc-en|audio=En-us-Potomac.ogg|p|ə|ˈ|t|oʊ|m|ə|k}}), provisional designation {{mp|1908 CG}}, is a dark Hildian asteroid from the outermost regions of the asteroid belt, approximately {{convert|73|km|mi|sigfig=2|sp=us}} in diameter. It was discovered on 4 February 1908, by American astronomer Joel Metcalf at the Taunton Observatory {{Obscode|803}} in Massachusetts, United States. The X-type asteroid has a rotation period of 11.4 hours. It was named for the Potomac River on which Washington, D.C. is located.
Orbit and classification
Potomac is member of the dynamical Hilda group, which stays in 3:2 orbital resonance with Jupiter. It is, however, not a member of the Hilda family but a non-family asteroid of the main belt's background population when applying the Hierarchical Clustering Method to its proper orbital elements.
It orbits the Sun in the outermost asteroid belt at a distance of 3.3–4.7 AU once every 7 years and 12 months (2,910 days; semi-major axis of 3.99 AU). Its orbit has an eccentricity of 0.18 and an inclination of 11° with respect to the ecliptic. The body's observation arc begins at the United States Naval Observatory, three weeks after its official discovery observation at Taunton.
Naming
This minor planet was named after the U.S. Potomac River in the Mid-Atlantic region of the United States, on which Washington, D.C. is located. The river flows from West Virginia into the Chesapeake Bay and forms the southern boundary of Maryland. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 ({{small|H 122}}).
Physical characteristics
In the Tholen classification, Potomac is an X-type asteroid. It has also been characterized as a carbonaceous C-type asteroid by Pan-STARRS photometric survey.
= Rotation period =
Two rotational lightcurves of Potomac was obtained from photometric observations. Lightcurve analysis gave a rotation period of 11.40 and 11.41 hours with a brightness amplitude of 0.22 and 0.24 magnitude, respectively ({{small|U=2/3}}).
= Diameter and albedo =
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Potomac measures between 71.82 and 76.72 kilometers in diameter and its surface has an albedo between 0.039 and 0.0439.
The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0439 and a diameter of 71.82 kilometers based on an absolute magnitude of 9.73.
References
{{reflist|30em|refs=
|type = 2019-05-10 last obs.
|title = JPL Small-Body Database Browser: 1345 Potomac (A908 CE)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001345
|archive-url = https://web.archive.org/web/20200820002945/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001345
|url-status = dead
|archive-date = 20 August 2020
|publisher = Jet Propulsion Laboratory
|accessdate = 29 October 2019}}
|last = Schmadel | first = Lutz D.
|title = Dictionary of Minor Planet Names |publisher = Springer Berlin Heidelberg
|page = 109
|date = 2007
|isbn = 978-3-540-00238-3
|doi = 10.1007/978-3-540-29925-7_1346 |chapter = (1345) Potomac }}
|title = 1345 Potomac (A908 CE)
|work = Minor Planet Center
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|accessdate = 29 October 2019}}
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|doi = 10.1088/0004-637X/744/2/197
|arxiv = 1110.0283
|s2cid = 44000310 |access-date= 17 November 2017}}
|title = Asteroid 1345 Potomac – Proper Elements
|publisher = AstDyS-2, Asteroids – Dynamic Site
|url = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=1345
|access-date= 29 October 2019}}
|title = LCDB Data for (1345) Potomac
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1345%7CPotomac
|accessdate = 17 November 2017}}
|display-authors = 6
|first1 = Fumihiko |last1 = Usui
|first2 = Daisuke |last2 = Kuroda
|first3 = Thomas G. |last3 = Müller
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|doi-access= free
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|display-authors = 6
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|date = June 1998
|title = A Study of Hilda Asteroids. V. Lightcurves of 47 Hilda Asteroids
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|first4 = Larry |last4 = Denneau
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|first8 = Richard J. |last8 = Wainscoat
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|first11 = Heather |last11 = Flewelling
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}}
External links
- [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&pg 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|1345}}
- {{JPL small body}}
{{Minor planets navigator |1344 Caubeta |number=1345 |1346 Gotha}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Potomac}}