Editing 11 Parthenope

{{Short description|Main-belt asteroid}}
{{Use dmy dates|date=January 2020}}
{{Infobox planet
| minorplanet = yes
| background = #D6D6D6
| name = 11 Parthenope
| symbol = [[File:Parthenope symbol (bold).svg|24px]] or [[File:Lyra symbol (bold).svg|24px]] (historical)
| image = 11 Parthenope VLT (2021), deconvolved.pdf
| image_size = 
| caption = Deconvolved [[VLT-SPHERE]] image of Parthenope
| discoverer = [[Annibale de Gasparis]]
| discovery_site = [[Astronomical Observatory of Capodimonte|Naples Obs.]]
| discovered = 11 May 1850
| mpc_name = (11) Parthenope
| alt_names = 
| pronounced = {{IPAc-en|p|ɑːr|ˈ|θ|ɛ|n|ə|p|i}} {{respell|parth|EN|ə|pee}}<ref>Noah Webster (1884) ''A Practical Dictionary of the English Language''</ref>
| named_after = [[Parthenope (Siren)|Parthenopē]]
| adjectives = Parthenopean ({{IPAc-en|ˌ|p|ɑːr|θ|ə|n|ə|ˈ|p|iː|ə|n}} {{respell|PARTH|ə|nə|PEE|ən}})<br />Parthenopian ({{IPAc-en|ˌ|p|ɑːr|θ|ə|ˈ|n|oʊ|p|i|ə|n}} {{respell|PARTH|ə|NOH|pee|ən}})<ref>{{OED|Parthenopean}}, {{OED|Parthenopian}}</ref>
| mp_category = [[Main belt]]
| orbit_ref = <ref name=jpldata>{{cite web
  |type=2024-11-29 last obs
  |title=JPL Small-Body Database Browser: 11 Parthenope
  |url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=11
  |accessdate=20 December 2024}}</ref>
| epoch = 17.0 October 2024 ([[Julian day|JD]] 2460600.5)
| semimajor = {{Convert|2.45337|AU|Gm|abbr=on}}
| perihelion = {{Convert|2.20942|AU|Gm|abbr=on}}
| time_periastron = 2024-Jan-12
| aphelion = {{Convert|2.69732|AU|Gm|abbr=on|lk=on}}
| eccentricity = 0.09943
| period = 3.84 [[Julian year (astronomy)|yr]] (1403.6 [[Julian year (astronomy)|d]])
| inclination = 4.63153°
| asc_node = 125.506°
| arg_peri = 196.071°
| mean_anomaly = 71.503[[Degree (angle)|°]]
| avg_speed = 19.02&nbsp;km/s
| flattening = 0.12{{efn|1=Flattening derived from the maximum aspect ratio (c/a): <math>f=1-\frac{c}{a}</math>, where (c/a) = {{val|0.88|0.05}}.<ref name=VLT/>}}
| dimensions = {{val|156|x|152|x|138}} ± 6 km<ref name=VLT/>
| mean_diameter = {{val|149|2|u=km}}<ref name=VLT>P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. ''Astronomy & Astrophysics'' 54, A56</ref><br />{{val|142.887|1.008|u=km}}<ref name=jpldata/>
| mass = {{val|5.5|0.4|e=18|u=kg}}<ref name=VLT/><br />{{val|6.15|e=18|u=kg}}<ref name=Baer/>
| density = {{val|3.20|0.27|u=g/cm3}}<ref name=VLT/><br />{{val|3.28|0.20|u=g/cm3}}<ref name=Baer/>
| surface_grav = 0.0578 m/s{{sup|2}}
| escape_velocity = 0.0941 km/s
| rotation = {{Convert|13.7204|h|d|abbr=on|lk=on}}<ref name=jpldata/><br>{{val|13.72204|0.00001|u=h}}<ref name=VLT/>
| axial_tilt = 73°<ref name=VLT/>
| spectral_type = [[S-type asteroid]]<ref name=jpldata/>
| magnitude = 8.68<ref name=AstDys-Parthenope >{{cite web |title=AstDys (11) Parthenope Ephemerides |publisher=Department of Mathematics, University of Pisa, Italy |url=https://newton.spacedys.com/astdys/index.php?pc=1.1.3.1&n=11&oc=500&y0=2031&m0=7&d0=29&h0=00&mi0=00&y1=2031&m1=7&d1=29&h1=00&mi1=00&ti=1.0&tiu=days |accessdate=26 June 2010}}</ref> to 12.16
| abs_magnitude = 6.73<ref name=jpldata/><br>6.55<ref name=VLT/>
| pole_ecliptic_lat = {{val|17|4|u=deg}}<ref name=VLT/>
| pole_ecliptic_lon = {{val|312|2|u=deg}}<ref name=VLT/>
| albedo = 0.187 (calculated)<ref name=VLT/><br />{{val|0.191|0.021}}<ref name=jpldata/>
| angular_size = 0.178" <!-- Horizons 2008-Aug-07 --> to 0.057"
| single_temperature = ~174 [[kelvin|K]]
| mean_motion = {{Deg2DMS|0.256484|sup=ms}} / day
| observation_arc = 63626 days (174.20 yr)
| uncertainty = 0
| moid = {{Convert|1.197|AU|Gm|abbr=on}}
| jupiter_moid = {{Convert|2.54059|AU|Gm|abbr=on}}
| tisserand = 3.483
}}

'''11 Parthenope''' ({{IPAc-en|p|ɑr|ˈ|θ|ɛ|n|ə|p|i}} {{respell|parth|EN|ə|pee}}) is a large, bright [[main-belt]] [[asteroid]].

Parthenope was discovered by [[Annibale de Gasparis]] on 11 May 1850, the second of his nine asteroid discoveries. It was named after [[Parthenope (Siren)|''Parthenopē'']], one of the [[Siren (mythology)|Siren]]s in [[Greek mythology]], said to have founded the city of [[Naples]]. De Gasparis "used his utmost endeavours to realise a 'Parthenope' in the heavens, such being the name suggested by Sir [[John Herschel]] on the occasion of the discovery of ''[[10 Hygiea|Hygiea]]'' in 1849".<ref>{{cite journal| bibcode=1850MNRAS..10..144D|  last=De Gasparis| first= Annibale| title=The New Planet Parthenope| journal= [[Monthly Notices of the Royal Astronomical Society]]| volume=10| pages=144–147  |date=May 1850| doi=10.1093/mnras/10.7.144| doi-access=free}}</ref> Two symbols were proposed for Parthenope: a fish and a star (in the pipeline for [[Unicode]] 17.0 as U+1CEC4 𜻄 [[File:Parthenope symbol (fixed width).svg|16px]]) while such symbols were still in use, and later a lyre (in the pipeline for Unicode 17.0 as U+1F77A 🝺 [[File:Lyra symbol (fixed width).svg|16px]]) in lists of symbols. Both are obsolete.<ref name=astunicode>{{cite web |url=https://www.unicode.org/L2/L2023/23207-historical-asteroids.pdf |title=Unicode request for historical asteroid symbols |last1=Bala |first1=Gavin Jared |last2=Miller |first2=Kirk |date=18 September 2023 |website=unicode.org |publisher=Unicode |access-date=26 September 2023 |quote=}}</ref><ref name=pipeline>{{cite web |url=https://unicode.org/alloc/Pipeline.html |title=Proposed New Characters: The Pipeline |author=Unicode |date= |website=unicode.org |publisher=The Unicode Consortium |access-date=6 November 2023 |quote=}}</ref>

There have been two observed Parthenopian [[occultation]]s, on 13 February 1987, and 28 April 2006.

On 6 August 2008, during a [[Apsis|perihelic]] [[Opposition (astronomy and astrology)|opposition]], Parthenope had an [[apparent magnitude]] of 8.8.

In 1988 a search for satellites or dust orbiting this asteroid was performed using the [[UH88]] telescope at the [[Mauna Kea Observatories]], but the effort came up empty.<ref name="Gradie1988"/>

Based upon a [[light curve]] that was generated from [[Photometry (astronomy)|photometric]] observations of this asteroid at [[Pulkovo Observatory]], it has a rotation period of 13.722 ± 0.001 hours and varies in brightness by 0.10 ± 0.0s in [[Magnitude (astronomy)|magnitude]]. The light curve displays three maxima and minima per cycle.<ref name="Pilcher2011"/> The JPL Small-Body Database lists a rotation period of 13.7204 hours.<ref name=jpldata/>

==Mass==
In 2007, Baer and Chesley calculated a higher mass and density for Parthenope based on [[Perturbation (astronomy)|perturbations]] by the 90&nbsp;km asteroid [[17 Thetis]].  Baer and Chesley calculated a mass of 6.3{{e|18}} kg with a density of 3.3 g/cm<sup>3</sup>.<ref name="Baer2007">{{cite journal
  |last=Baer |first=James
  |author2=Steven R. Chesley
  |title=Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris
  |journal=Celestial Mechanics and Dynamical Astronomy
  |volume=100 |issue=2008 |pages=27–42
  |publisher=Springer Science+Business Media B.V. 2007
  |doi=10.1007/s10569-007-9103-8
  |date=2008 |bibcode = 2008CeMDA.100...27B |doi-access=free
  }}</ref> 2008 estimates by Baer suggest a mass of 6.15{{e|18}} kg.<ref name=Baer>{{cite web
  |date=2008
  |title=Recent Asteroid Mass Determinations
  |publisher=Personal Website
  |author=Jim Baer
  |url=http://home.earthlink.net/~jimbaer1/astmass.txt
  |accessdate=6 December 2008
  |archive-url=https://web.archive.org/web/20130702212735/http://home.earthlink.net/~jimbaer1/astmass.txt
  |archive-date=2 July 2013
  |url-status=dead
  }}</ref> The 1997 and 2001 estimates by Viateau and Rapaport were closer to 5{{e|18}} kg with a density of 2.7 g/cm<sup>3</sup>.<ref name="Baer2007"/>

==See also==
* [[List of former planets]]

== Notes ==
{{notelist}}

== References ==
{{Reflist|30em|refs=
<ref name="Pilcher2011">{{Citation
 | first1    = Frederick
 | last1     = Pilcher
 | title     = Rotation Period Determinations for 11 Parthenope, 38 Leda, 111 Ate 194 Prokne, 217 Eudora, and 224 Oceana
 | work      = The Minor Planet Bulletin
 | volume    = 38
 | issue     = 4
 | pages      = 183–185
 | date     = October 2011
 | bibcode   = 2011MPBu...38..183P
 | postscript= .
}}</ref>

<ref name="Gradie1988">{{Citation
 | last1     = Gradie
 | first1    = J.
 | last2     = Flynn
 | first2    = L.
 | title     = A Search for Satellites and Dust Belts Around Asteroids: Negative Results
 | work      = Abstracts of the Lunar and Planetary Science Conference
 | volume    = 19
 | pages     = 405–406 
 | date     = March 1988
 | bibcode   = 1988LPI....19..405G
 | postscript= .
}}</ref>
}}

== External links ==
* [http://www.minorplanetobserver.com/pdolc/A11_2008.HTM Lightcurve plot of 11 Parthenope], Palmer Divide Observatory, [[Brian D. Warner|B. D. Warner]] (2008)
* [https://web.archive.org/web/20181209184743/http://www.lunar-occultations.com/iota/iotandx.htm IOTA] (International Occultation Timing Association) occultation database
* [https://web.archive.org/web/20140108170353/http://www.asteroidoccultation.com/observations/Results/Data2011/20110126_Parthenope_InversionModel.jpg 2011-Jan-26 Occultation] / [https://web.archive.org/web/20140108170501/http://www.asteroidoccultation.com/observations/Results/index2011.html (2011 Asteroidal Occultation Results for North America)]
* {{AstDys|11}}
* {{JPL small body}}

{{Minor planets navigator |10 Hygiea |number=11 |12 Victoria}}
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{{DEFAULTSORT:Parthenope}}
[[Category:Background asteroids|000011]]
[[Category:Discoveries by Annibale de Gasparis]]
[[Category:Named minor planets]]
[[Category:S-type asteroids (Tholen)|000011]]
[[Category:Sk-type asteroids (SMASS)|000011]]
[[Category:Astronomical objects discovered in 1850|18500511]]