View source for 76 Freia

{{Short description|Large main-belt asteroid}}
{{Use dmy dates|date=January 2025}}
{{Infobox planet
 | minorplanet=yes
 | background=#D6D6D6
 | name=76 Freia
 | image=76Freia (Lightcurve Inversion).png
 | image_scale =
 | caption=A three-dimensional model of 76 Freia based on its light curve.
 | discoverer=[[Heinrich d'Arrest]]
 | discovered=21 October 1862
 | mpc_name=(76) Freia
 | alt_names=
 | pronounced = {{IPAc-en|ˈ|f|r|eɪ|.|ə}}<ref>{{Cite encyclopedia |url=http://www.lexico.com/definition/Freya |archive-url=https://web.archive.org/web/20200322185657/https://www.lexico.com/definition/freya |url-status=dead |archive-date=22 March 2020 |title=Freya |dictionary=[[Lexico]] UK English Dictionary |publisher=[[Oxford University Press]]}}</ref>
 | adjective = Freian
 | named_after = [[Freyja]]
 | mp_category=Outer [[main belt]]<ref name=jpldata/> ([[Cybele asteroid|Cybele]])
 | epoch=31 December 2006 ([[Julian day|JD]] 2454100.5)
 | semimajor=511.306 Gm (3.418 [[Astronomical unit|AU]])
 | perihelion=427.898 Gm (2.860 AU)
 | aphelion=594.715 Gm (3.975 AU)
 | eccentricity=0.163
 | period=2307.979 d (6.32 [[Julian year (astronomy)|a]])
 | inclination=2.116°
 | asc_node=204.535°
 | arg_peri=254.070°
 | mean_anomaly=299.268°
 | avg_speed=16.00&nbsp;km/s
 | dimensions={{val|183.7|4|u=km}}<ref name=jpldata>{{cite web
  |type=2008-03-04 last obs
  |title=JPL Small-Body Database Browser: 76 Freia
  |url=https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=76
  |access-date=2010-09-05}}</ref>
 | mass={{nowrap|(1.97 ± 4.20) × 10<sup>18</sup> kg<ref name="Carry2012"/>}}
 | density=0.79 ± 1.69<ref name="Carry2012"/> g/cm<sup>3</sup>
 | surface_grav=0.0513 m/s<sup>2</sup>
 | escape_velocity=0.0971 km/s
 | rotation={{Val|9.968240|0.000009|u=hours}}<ref name=Stephens2008/>
 | spectral_type=CP
 | abs_magnitude=7.90
 | albedo=0.036<ref>[http://www.psi.edu/pds/resource/albedo.html Asteroid Data Sets<!-- Bot generated title -->] {{webarchive|url=https://web.archive.org/web/20091217104722/http://www.psi.edu/pds/resource/albedo.html |date=2009-12-17 }}</ref>
}}

'''76 Freia''' is a very large [[main-belt]] [[asteroid]]. It orbits in the outer part of the asteroid belt and is classified as a [[Cybele asteroid]].<ref name=De_Prá_et_al_2018/> Its composition is very primitive and it is extremely dark in color. Freia was discovered by the [[astronomer]] [[Heinrich d'Arrest]] on 21 October 1862, in [[Copenhagen]], Denmark. It was his first and only asteroid discovery. It is named after the goddess [[Freyja]] in [[Norse mythology]].

The sidereal [[orbital period]] of this asteroid is [[Commensurability (astronomy)|commensurable]] with that of [[Jupiter]], which made it useful for ground-based mass estimates of the [[giant planet]].<ref name=Klepczynski1971/> A shape model for the asteroid was published by Stephens and Warner (2008), based upon [[lightcurve]] data. This yielded a sidereal [[rotation period]] of {{Val|9.968240|0.000009|u=hours}}. They found two possible solutions for the spin axis, with the preferred solution in [[ecliptic coordinates]] being (λ, β) = ({{Val|139|5|u=°}}, {{Val|25|5|u=°}}).<ref name=Stephens2008/>

==References==
{{Reflist|refs=

<ref name=De_Prá_et_al_2018>{{Citation
 | title=PRIMASS visits Hilda and Cybele groups
 | last1=De Prá | first1=M. N. | last2=Pinilla-Alonso | first2=N.
 | last3=Carvano | first3=J. M. | last4=Licandro | first4=J.
 | last5=Campins | first5=H. | last6=Mothé-Diniz | first6=T.
 | last7=De León | first7=J. | last8=Alí-Lagoa | first8=V.
 | display-authors=1 | journal=Icarus
 | volume=311 | pages=35–51 | date=September 2018
 | arxiv=1711.02071 | bibcode=2018Icar..311...35D 
 | doi=10.1016/j.icarus.2017.11.012 | s2cid=119383924 | postscript=. }}</ref>

<ref name=Klepczynski1971>{{citation
 | title=The Mass of Jupiter from the Motion of (76) Freia
 | display-authors=1 | last1=Klepczynski | first1=W. J.
 | last2=Janiczek | first2=P. M. | last3=Fiala | first3=A. D.
 | journal=Astronomical Journal | postscript=.
 | volume=76 | page=939 | date=November 1971
 | doi=10.1086/111204 | bibcode=1971AJ.....76..939K }}</ref>

<ref name=Stephens2008>{{citation
 | title=A Preliminary Shape and Spin Axis Model for 76 Freia
 | last1=Stephens | first1=Robert D. | last2=Warner | first2=Brian D.
 | journal=The Minor Planet Bulletin
 | volume=35 | issue=2 | pages=84–85 | date=June 2008
 | bibcode=2008MPBu...35...84S | postscript=. }}</ref>

<ref name="Carry2012">{{Citation
 | first1    = B.
 | last1     = Carry
 | title     = Density of asteroids
 | journal      = [[Planetary and Space Science]]
 | volume    = 73
 | pages      = 98–118
 |date=December 2012
 | issue = 1
 | doi       = 10.1016/j.pss.2012.03.009
 | bibcode   = 2012P&SS...73...98C
 | postscript= .
|arxiv = 1203.4336 | s2cid = 119226456
 }} See Table 1.</ref>
}}

==External links==
* {{AstDys|76}}
* {{JPL small body}}

{{Minor planets navigator |75 Eurydike |number=76 |77 Frigga}}
{{Small Solar System bodies}}
{{Authority control}}

{{DEFAULTSORT:000076}}
[[Category:Cybele asteroids]]
[[Category:Discoveries by Heinrich Louis d'Arrest|Freia]]
[[Category:Named minor planets|Freia]]
[[Category:P-type asteroids (Tholen)]]
[[Category:X-type asteroids (SMASS)]]
[[Category:Astronomical objects discovered in 1862|18621021]]


{{C-beltasteroid-stub}}