View source for 38 Leda

{{Short description|Main-belt asteroid}}
{{Other uses of|Leda|Leda (disambiguation){{!}}Leda}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
| background = #D6D6D6
| name = 38 Leda
| image = 38Leda (Lightcurve Inversion).png
| image_scale = 
| caption = A three-dimensional model of 38 Leda based on its light curve
| discoverer = [[Jean Chacornac|J. Chacornac]]
| discovered = January 12, 1856
| mpc_name = (38) Leda
| pronounced = {{IPAc-en|ˈ|l|iː|d|ə}}<ref>Noah Webster (1884) ''A Practical Dictionary of the English Language''</ref>
| adjective = Ledean {{IPAc-en|l|ᵻ|ˈ|d|iː|ə|n}} (Latin ''Lēdæ-us'')
| alt_names = A904 SF; {{mp|1949 QO|2}}
| named_after = [[Leda (mythology)|Leda]]
| mp_category = [[Main belt]]
| epoch = December 31, 2006 ([[Julian day|JD]] 2454100.5)
| semimajor = 410.409 Gm (2.743 [[Astronomical unit|AU]])
| perihelion = 348.232 Gm (2.328 AU)
| aphelion = 472.587 Gm (3.159 AU)
| eccentricity = 0.152
| period = 1659.725 d (4.54 [[Julian year (astronomy)|a]])
| inclination = 6.955°
| asc_node = 295.890°
| arg_peri = 168.804°
| mean_anomaly = 107.567°
| avg_speed = 17.88 km/s
| dimensions = 92.255 ± 0.490 km<ref name="JPL"/>
| mass = {{nowrap|(7.16 ± 3.38/2.24){{e|17}} kg<ref name="FiengaEtAl2020"/>}}
| density = 1.743 ± 0.822/0.544 g/cm<sup>3</sup><ref name="FiengaEtAl2020"/>
| surface_grav = {{Gr|7.16e-4|46.1275|4}} m/s²
| escape_velocity = {{V2|7.16e-4|46.1275|4}} km/s
| rotation = 0.5350 d (12.84 h) <ref name="JPL">{{Cite SBDB|title=38 Leda|id=38|access-date=2008-06-15}}</ref>
| spectral_type = [[C-type asteroid|C]]<ref name="JPL"/>
| abs_magnitude = 8.32
| albedo = 0.055 <ref name="JPL"/>
| single_temperature = ~170 [[kelvin|K]]
}}

'''38 Leda''' is a large, dark [[main-belt]] [[asteroid]] that was discovered by French astronomer [[Jean Chacornac|J. Chacornac]] on January 12, 1856, and named after [[Leda (mythology)|Leda]], the mother of [[Helen of Troy]] in [[Greek mythology]]. In the [[Tholen classification]] system, it is categorized as a carbonaceous [[C-type asteroid]], while the Bus [[asteroid taxonomy]] system lists it as a Cgh asteroid.<ref name="DeMeo2011"/> The spectra of the asteroid displays evidence of aqueous alteration.<ref name=Fornasier1999/>

Leda has been studied by [[radar astronomy|radar]].<ref name="detected"/> During 2002, 38 Leda was observed by radar from the [[Arecibo Observatory]]. The return signal matched an effective diameter of 116 ± 13&nbsp;km. This is consistent with some asteroid dimensions computed through other means.<ref name="icarus186_1_126"/><ref name="Carry2012"/> 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 12.834 ± 0.001 hours and varies in brightness by 0.15 ± 0.01 in [[Magnitude (astronomy)|magnitude]].<ref name="Pilcher2011"/>

==References==
{{Reflist|refs=

<ref name=Fornasier1999>{{citation
 | title=Spectroscopic comparison of aqueous altered asteroids with CM2 carbonaceous chondrite meteorites
 | display-authors=1 | postscript=.
 | last1=Fornasier | first1=S. | last2=Lazzarin | first2=M.
 | last3=Barbieri | first3=C. | last4=Barucci | first4=M. A.
 | journal=Astronomy and Astrophysics Supplement
 | volume=135 | pages=65−73 | date=February 1999
 | doi=10.1051/aas:1999161 | bibcode=1999A&AS..135...65F | doi-access=free }}</ref>

<ref name="Carry2012">{{Citation
 | first1    = B.
 | last1     = Carry
 | title     = Density of asteroids
 | journal      = Planetary and Space Science
 | volume    = 73
 | issue = 1
 | pages      = 98–118
 |date=December 2012
 | doi       = 10.1016/j.pss.2012.03.009
 | bibcode   = 2012P&SS...73...98C
 | postscript= .
|arxiv = 1203.4336 }} See Table 1.</ref>

<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
 | journal      = The Minor Planet Bulletin
 | volume    = 38
 | issue     = 4
 | pages      = 183–185
 |date=October 2011
 | bibcode   = 2011MPBu...38..183P
 | postscript= .}}</ref>

<ref name="icarus186_1_126">{{citation
 | last1=Magri
 | first1=Christopher
 | last2=Nolan
 | first2=Michael C.
 | last3=Ostro
 | first3=Steven J.
 | last4=Giorgini
 | first4=Jon D.
 | display-authors=1
 | title=A radar survey of main-belt asteroids: Arecibo observations of 55 objects during 1999–2003
 | journal=Icarus
 | volume=186
 | issue=1
 | pages=126–151
 |date=January 2007
 | doi=10.1016/j.icarus.2006.08.018
 | bibcode=2007Icar..186..126M}}</ref>

<ref name="DeMeo2011">{{Citation
 |first1=Francesca E. 
 |last1=DeMeo 
 |first2=Richard P. 
 |last2=Binzel 
 |first3=Stephen M. 
 |last3=Slivan 
 |first4=Schelte J. 
 |last4=Bus 
 |display-authors=1 
 |title=An extension of the Bus asteroid taxonomy into the near-infrared 
 |journal=Icarus 
 |volume=202 
 |issue=1 
 |pages=160–180 
 |year=2011 
 |doi=10.1016/j.icarus.2009.02.005 
 |bibcode=2009Icar..202..160D 
 |url=http://www.tara.tcd.ie/bitstream/2262/43276/1/PEER_stage2_10.1016%252Fj.icarus.2009.02.005.pdf 
 |access-date=2013-04-12 
 |postscript=. 
 |url-status=dead 
 |archiveurl=https://web.archive.org/web/20140317200310/https://www.tara.tcd.ie/bitstream/2262/43276/1/PEER_stage2_10.1016/j.icarus.2009.02.005.pdf 
 |archivedate=2014-03-17 
}} See appendix A.</ref>

<ref name="detected">{{cite web
 | title=Radar-Detected Asteroids and Comets
 | publisher=NASA/JPL Asteroid Radar Research
 | url=http://echo.jpl.nasa.gov/asteroids/
 | access-date=2011-10-30}}</ref>

<ref name="FiengaEtAl2020">{{Cite journal 
  |last1=Fienga |first1=A.
  |last2=Avdellidou |first2=C.
  |last3=Hanuš |first3=J.
  |date=February 2020
  |title=Asteroid masses obtained with INPOP planetary ephemerides
  |url=https://academic.oup.com/mnras/article/492/1/589/5658701
  |journal=Monthly Notices of the Royal Astronomical Society
  |volume=492
  |issue=1
  |pages=589–602
 |doi=10.1093/mnras/stz3407
  |doi-access=free}}</ref>

}} <!-- end of reflist -->

==External links==
* {{AstDys|38}}
* {{JPL small body}}

{{Minor planets navigator |37 Fides |number=38 |39 Laetitia}}
{{Small Solar System bodies}}
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{{DEFAULTSORT:000038}}
[[Category:Background asteroids]]
[[Category:Discoveries by Jean Chacornac|Leda]]
[[Category:Named minor planets|Leda]]
[[Category:C-type asteroids (Tholen)]]
[[Category:Cgh-type asteroids (SMASS)]]
[[Category:Astronomical objects discovered in 1856|18560112]]
[[Category:Leda (mythology)]]