4001 Ptolemaeus
{{Short description|Main-belt asteroid}}
{{Use dmy dates|date=March 2018}}
{{Infobox planet
| minorplanet = yes
| name = 4001 Ptolemaeus
| background = #D6D6D6
| image = Orbit of 4001 Ptolemaeus.gif
| image_scale =
| caption = Orbit of 4001 Ptolemaeus
| discoverer = K. Reinmuth
| discovery_site = Heidelberg Obs.
| discovered = 2 August 1949
| mpc_name = (4001) Ptolemaeus
| alt_names = 1949 PV{{·}}{{mp|1949 QD|1}}
{{mp|1982 BU|9}}{{·}}1987 OE
| pronounced = {{IPAc-en|t|ɒ|l|ə|'|m|iː|ə|s}}
| named_after = Ptolemy
{{nowrap|{{small|(Greco-Roman astronomer)}}}}
| mp_category = main-belt{{·}}{{small|(inner)}}
Flora
| epoch = 23 March 2018 (JD 2458200.5)
| uncertainty = 0
| observation_arc = 67.75 yr (24,744 d)
| aphelion = 2.6809 AU
| perihelion = 1.8940 AU
| semimajor = 2.2874 AU
| eccentricity = 0.1720
| period = 3.46 yr (1,264 d)
| mean_anomaly = 294.51°
| mean_motion = {{Deg2DMS|0.2849|sup=ms}} / day
| inclination = 5.4568°
| asc_node = 130.67°
| arg_peri = 204.09°
| mean_diameter = {{val|4.641|0.297|ul=km}}
{{val|5.0|u=km}} {{small|(est. at 0.24)}}
| rotation =
| albedo = {{val|0.392|0.056}}
| spectral_type = SMASS {{=}} S
}}
4001 Ptolemaeus, provisional designation {{mp|1949 PV}}, is a Florian asteroid from the inner regions of the asteroid belt, approximately {{convert|5|km|mi|abbr=off|sp=us}} in diameter. It was discovered on 2 August 1949, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Heidelberg, Germany. In 1991, the International Astronomical Union named the S-type asteroid after Greco-Roman astronomer Ptolemy.
Orbit and classification
Ptolemaeus is a member of the Flora family ({{small|402}}), a giant asteroid family and the largest family of stony asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 1.9–2.7 AU once every 3 years and 6 months (1,264 days; semi-major axis of 2.29 AU). Its orbit has an eccentricity of 0.17 and an inclination of 5° with respect to the ecliptic.
The body's observation arc begins with its observations as {{mp|1949 QD|1}} at Lowell Observatory on 24 August 1949, or three weeks after its official discovery observation at Heidelberg. On 24 April 1989, Ptolemaeus approached the asteroid 6 Hebe within 5.5 million kilometers at a relative velocity of 3.7 km/s.
Physical characteristics
In the SMASS classification, Ptolemaeus is a common, stony S-type asteroid, which is in agreement with the overall spectral type for members of the Flora family.{{rp|23}}
= Diameter and albedo =
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Ptolemaeus measures 4.641 kilometers in diameter and its surface has a high albedo of 0.392. Based on a generic magnitude-to-diameter conversion, assuming a Flora-type typical albedo of 0.24, the asteroid measures 5.0 kilometers for an absolute magnitude of 13.7.
= Rotation period =
As of 2018, no rotational lightcurve of Ptolemaeus has been obtained from photometric observations. Its rotation period, poles and shape remain unknown.
Naming
This minor planet was named after 2nd-century Greco-Roman astronomer Ptolemy (Latin: "Ptolemaeus") by IAU's Minor Planet Names Committee. He is best known for his influential Almagest, a mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Its ideas dominated astronomy for 1200 years until Copernicus in the early Renaissance. The official naming citation was published by the Minor Planet Center on 21 November 1991 ({{small|M.P.C. 19335}}).
References
{{reflist|30em|refs=
|type = 2017-05-01 last obs.
|title = JPL Small-Body Database Browser: 4001 Ptolemaeus (1949 PV)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2004001
|publisher = Jet Propulsion Laboratory
|access-date = 16 March 2018}}
|title = 4001 Ptolemaeus (1949 PV)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=4001
|access-date = 16 March 2018}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|access-date = 16 March 2018}}
|title = Asteroid 4001 Ptolemaeus – Nesvorny HCM Asteroid Families V3.0
|work = Small Bodies Data Ferret
|url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=4001+Ptolemaeus#Asteroid%204001%20PtolemaeusEAR-A-VARGBDET-5-NESVORNYFAM-V3.0
|access-date = 27 October 2019}}
|first1 = D. |last1 = Nesvorný
|first2 = M. |last2 = Broz
|first3 = V. |last3 = Carruba
|date = December 2014
|chapter = Identification and Dynamical Properties of Asteroid Families
|title = Asteroids IV
|pages = 297–321
|bibcode = 2015aste.book..297N
|doi = 10.2458/azu_uapress_9780816532131-ch016
|arxiv = 1502.01628
|isbn = 9780816532131
}}
|display-authors = 6
|first1 = Joseph R. |last1 = Masiero
|first2 = A. K. |last2 = Mainzer
|first3 = T. |last3 = Grav
|first4 = J. M. |last4 = Bauer
|first5 = R. M. |last5 = Cutri
|first6 = J. |last6 = Dailey
|first7 = P. R. M. |last7 = Eisenhardt
|first8 = R. S. |last8 = McMillan
|first9 = T. B. |last9 = Spahr
|first10 = M. F. |last10 = Skrutskie
|first11 = D. |last11 = Tholen
|first12 = R. G. |last12 = Walker
|first13 = E. L. |last13 = Wright
|first14 = E. |last14 = DeBaun
|first15 = D. |last15 = Elsbury
|first16 = T. IV |last16 = Gautier
|first17 = S. |last17 = Gomillion
|first18 = A. |last18 = Wilkins
|date = November 2011
|title = Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters
|journal = The Astrophysical Journal
|volume = 741
|issue = 2
|page = 20
|bibcode = 2011ApJ...741...68M
|doi = 10.1088/0004-637X/741/2/68
|arxiv = 1109.4096
}}
|title = Asteroid Size Estimator
|publisher = CNEOS NASA/JPL
|url = https://cneos.jpl.nasa.gov/tools/ast_size_est.html
|access-date = 12 November 2017}}
}}
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|4001}}
- {{JPL small body}}
{{Minor planets navigator |4000 Hipparchus |number=4001 |4002 Shinagawa}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Ptolemaeus}}