View source for 704 Interamnia

{{Short description|Large asteroid in the asteroid belt}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
 | minorplanet=yes
 | background=#D6D6D6
 | name=704 Interamnia
 | image=704 Interamnia VLT (2021), deconvolved.pdf
 | image_size = 
 | caption=
 | discoverer=[[Vincenzo Cerulli]]
 | discovered=2 October 1910
 | mpc_name=(704) Interamnia
 | alt_names=1910 KU; 1952 MW
 | pronounced={{IPAc-en|ɪ|n|t|ər|ˈ|æ|m|n|i|ə}}<ref name=OED/>
 | adjective=Interamnian {{IPAc-en|ɪ|n|t|ər|ˈ|æ|m|n|i|ə|n}}<ref name=OED>{{OED|interamnian}}</ref>
 | named_after=[[Teramo]]
 | mp_category=[[Asteroid belt|Main belt]]
 | orbit_ref = <ref name=JPL>{{cite web
  |type=2024-06-21 last obs
  |title=JPL Small-Body Database Browser: 704 Interamnia (1910 KU)
  |url=https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=704
  |access-date=19 Dec 2024}}</ref>
 | epoch=July 01, 2021 <br />([[Julian day|JD]] 2459396.5, heliocentric)
 | aphelion={{Convert|3.53|AU|Gm|abbr=on|lk=on}}
 | perihelion={{Convert|2.58|AU|Gm|abbr=on}}
 | semimajor={{Convert|3.056|AU|Gm|abbr=on}}
 | eccentricity=0.155
 | period=5.34 [[Julian year (astronomy)|yr]] (1951 [[Julian year (astronomy)|d]])
 | inclination=17.31°
 | asc_node=280.3°
 | arg_peri=94.8°
 | mean_anomaly=248°
 | avg_speed=16.92 km/s{{citation needed|date=September 2021}}
 | dimensions = {{val|362|x|348|x|310}} ± 8 km<ref name="Hanus2019"/>
 | flattening = 0.14{{efn|1=Flattening derived from the maximum aspect ratio (c/a): <math>f=1-\frac{c}{a}</math>, where (c/a) = {{val|.86|.03}}.<ref name=VLT/>}}
 | mean_diameter={{val|332|5|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|332|6|u=km}} {{small|(volume equivalent)}}<ref name="Hanus2019"/>
 |mass={{val|35|5|e=18|u=kg}}<ref name=VLT/><br />{{val|38|13|e=18|u=kg}}<ref name="Hanus2019"/>
 |density={{val|1.84|.28|u=g/cm3}}<ref name=VLT/><br />{{val|2.0|0.7|u=g/cm3}}<ref name="Hanus2019"/>
 | rotation=8.71 [[hour|h]]<ref name="Hanus2019"/><br>8.727 h<ref name=JPL/>
 |pole_ecliptic_lat={{val|62|5}}°
 |pole_ecliptic_lon={{val|87|5}}°
 | spectral_type=[[F-type asteroid|F]]/[[B-type asteroid|B]]<ref name=JPL/>
 | magnitude=9.9 to 13.0<ref name=bright2007/>
 | abs_magnitude=6.35<ref name=JPL/>
 | albedo={{val|.067}}<ref name=VLT/><br />{{val|0.078|0.014}} geometric ({{val|0.645|0.014}} BV, {{val|0.259|0.021}} UB)<ref name=JPL/>
 | mean_motion={{Deg2DMS|0.1845|sup=ms}} / day
 | observation_arc=110.8 yr
 | uncertainty=0
}}

'''704 Interamnia''' is a large [[F-type asteroid]]. With a [[mean diameter]] of around 330 kilometres, it is the [[List of exceptional asteroids|fifth-largest asteroid]], after [[Ceres (dwarf planet)|Ceres]], [[4 Vesta|Vesta]], [[2 Pallas|Pallas]] and [[10 Hygiea|Hygiea]]. Its mean distance from the [[Sun]] is 3.067 [[astronomical unit|AU]]. It was discovered on 2 October 1910 by [[Vincenzo Cerulli]], and named after the [[Latin]] name for [[Teramo]], [[Italy]], where Cerulli worked. Its [[List of exceptional asteroids#Largest by mass|mass]] is probably between fifth and tenth highest in the asteroid belt, with a mass estimated to be 1.2% of the mass of the entire asteroid belt.<ref>{{Cite journal|url=http://iau-comm4.jpl.nasa.gov/EPM2004.pdf |doi=10.1007/s11208-005-0033-2 |title=High-Precision Ephemerides of Planets—EPM and Determination of Some Astronomical Constants |journal=Solar System Research |volume=39 |issue=3 |pages=176–186 |date=2005 |last1=Pitjeva |first1=E. V. |s2cid=120467483 |bibcode=2005SoSyR..39..176P |url-status=dead |archive-url=https://web.archive.org/web/20081031065523/http://iau-comm4.jpl.nasa.gov/EPM2004.pdf |archive-date=2008-10-31 }} 15 = 0.0124</ref> Observations by the [[Very Large Telescope]]'s [[VLT-SPHERE|SPHERE]] imager in 2017–2019, combined with occultation results, indicate that the shape of Interamnia may be consistent with [[hydrostatic equilibrium]] for a body of its density with a rotational period of 7.6 hours. (Its current period is 8.7 hours.) This suggests that Interamnia may have formed as an equilibrium body, and that impacts changed its rotational period after it fully solidified.<ref name="Hanus2019"/>

==Characteristics==
[[File:Interamnia medie.gif|thumb|left|upright|Observations of 704 Interamnia carried out at the Observatory of Teramo (founded by the discoverer of the asteroid, Vincenzo Cerulli) for the 101st anniversary since its discovery. The animation shows Interamnia's path over three hours.]]
[[File:704 cerulli low.jpg|thumb|left|upright|One of the first photographic plates of 704 Interamnia. The image was taken in Oct. 1910; the path of the asteroid is shown in the zoom.]]

Although Interamnia is the largest asteroid after the [[List of exceptional asteroids#Largest by diameter|"big four"]], it is a very little-studied body. It is easily the largest of the [[F-type asteroid]]s, but until 2017-2019 there existed very few details of its internal composition or shape, and no [[light curve]] analysis has yet been done to determine the ecliptic coordinates of Interamnia's poles (and hence its [[axial tilt]]). Studies by the Very Large Telescope give an average diameter of about 332&nbsp;km and found an ellipsoidal shape for Interamnia, similar to 4 Vesta; the resulting density calculation (1.98 ± 0.68 g·cm<sup>−3</sup>) is not precise enough to definitely infer Interamnia's composition, but the presence of hydrated materials at the surface and its overall spectral similarities to Ceres suggest that it is likely an icy body. The absence of an affiliated asteroid family implies that Interamnia has not suffered a giant impact within the past 3 billion years,<ref>{{cite journal|arxiv=1911.13049|doi=10.1051/0004-6361/201936639|title=(704) Interamnia: A transitional object between a dwarf planet and a typical irregular-shaped minor body|year=2020|last1=Hanuš|first1=J.|last2=Vernazza|first2=P.|last3=Viikinkoski|first3=M.|last4=Ferrais|first4=M.|last5=Rambaux|first5=N.|last6=Podlewska-Gaca|first6=E.|last7=Drouard|first7=A.|last8=Jorda|first8=L.|last9=Jehin|first9=E.|last10=Carry|first10=B.|last11=Marsset|first11=M.|last12=Marchis|first12=F.|last13=Warner|first13=B.|last14=Behrend|first14=R.|last15=Asenjo|first15=V.|last16=Berger|first16=N.|last17=Bronikowska|first17=M.|last18=Brothers|first18=T.|last19=Charbonnel|first19=S.|last20=Colazo|first20=C.|last21=Coliac|first21=J.-F.|last22=Duffard|first22=R.|last23=Jones|first23=A.|last24=Leroy|first24=A.|last25=Marciniak|first25=A.|last26=Melia|first26=R.|last27=Molina|first27=D.|last28=Nadolny|first28=J.|last29=Person|first29=M.|last30=Pejcha|first30=O.|s2cid=208512707|journal=Astronomy & Astrophysics|volume=633|pages=A65|bibcode=2020A&A...633A..65H|display-authors=29}}</ref> in contrast to 4 Vesta and 10 Hygiea.<ref>{{Cite journal |s2cid = 206541950|doi = 10.1126/science.1223272|title = The Geologically Recent Giant Impact Basins at Vesta's South Pole|year = 2012|last1 = Schenk|first1 = P.|last2 = O'Brien|first2 = D. P.|last3 = Marchi|first3 = S.|last4 = Gaskell|first4 = R.|last5 = Preusker|first5 = F.|last6 = Roatsch|first6 = T.|last7 = Jaumann|first7 = R.|last8 = Buczkowski|first8 = D.|last9 = McCord|first9 = T.|last10 = McSween|first10 = H. Y.|last11 = Williams|first11 = D.|last12 = Yingst|first12 = A.|last13 = Raymond|first13 = C.|last14 = Russell|first14 = C.|journal = Science|volume = 336|issue = 6082|pages = 694–697|pmid = 22582256|bibcode = 2012Sci...336..694S}}</ref><ref>{{cite journal |last1=Vernazza |first1=P. |last2=Jorda |first2=L. |last3=Ševeček |first3=P. |last4=Brož |first4=M. |last5=Viikinkoski |first5=M. |last6=Hanuš |first6=J. |last7=Carry |first7=B. |last8=Drouard |first8=A. |last9=Ferrais |first9=M. |last10=Marsset |first10=M. |last11=Marchis |first11=F. |last12=Birlan |first12=M. |last13=Podlewska-Gaca |first13=E. |last14=Jehin |first14=E. |last15=Bartczak |first15=P. |last16=Dudzinski |first16=G. |last17=Berthier |first17=J. |last18=Castillo-Rogez |first18=J. |last19=Cipriani |first19=F. |last20=Colas |first20=F. |last21=DeMeo |first21=F. |last22=Dumas |first22=C. |last23=Durech |first23=J. |last24=Fetick |first24=R. |last25=Fusco |first25=T. |last26=Grice |first26=J. |last27=Kaasalainen |first27=M. |last28=Kryszczynska |first28=A. |last29=Lamy |first29=P. |last30=Le Coroller |first30=H. |last31=Marciniak |first31=A. |last32=Michalowski |first32=T. |last33=Michel |first33=P. |last34=Rambaux |first34=N. |last35=Santana-Ros |first35=T. |last36=Tanga |first36=P. |last37=Vachier |first37=F. |last38=Vigan |first38=A. |last39=Witasse |first39=O. |last40=Yang |first40=B. |last41=Gillon |first41=M. |last42=Benkhaldoun |first42=Z. |last43=Szakats |first43=R. |last44=Hirsch |first44=R. |last45=Duffard |first45=R. |last46=Chapman |first46=A. |last47=Maestre |first47=J. L. |title=A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea |journal=Nature Astronomy |date=February 2020 |volume=4 |issue=2 |pages=136–141 |doi=10.1038/s41550-019-0915-8 |bibcode=2020NatAs...4..136V |hdl=10261/204968 |s2cid=209938346 |url=https://www.eso.org/public/archives/releases/sciencepapers/eso1918/eso1918a.pdf |access-date=March 30, 2022}}</ref>

Its very dark surface and relatively large distance from the Sun means Interamnia can never be seen with 10x50 [[binoculars]]. At most [[opposition (astronomy and astrology)|oppositions]] its [[apparent magnitude|magnitude]] is around +11.0, which is less than the ''minimum'' brightness of Vesta, Ceres or Pallas. Even at a [[Apsis|perihelic]] opposition its magnitude is only +9.9,<ref name=bright2007/> which is over four magnitudes lower than Vesta.

==Surface==

There are no deep basins visible in the VLT images. Any large craters must have flat floors, consistent with an icy C/F-type composition.<ref>Hanuš et al. 2020</ref>

==Mass==
In 2001, Michalak estimated Interamnia to have a mass of {{val|7|2|e=19|u=kg}}. Michalak's estimate depends on the masses of [[19 Fortuna]], [[29 Amphitrite]], and [[16 Psyche]]; thus this mass was obtained assuming an incomplete dynamical model.<ref name=Michalak2001/>

In 2011, Baer calculated Interamnia had a mass of {{val|3.9|.2|e=19|u=kg}}.<ref name=Baer/>

Goffin's 2014 astrometric reanalysis gives an even lower mass of {{val|2.7|0.1|e=19|u=kg}}.<ref>{{cite journal|arxiv=1402.4241|last1=Goffin|first1=Edwin|s2cid=118444915|title=Astrometric asteroid masses: A simultaneous determination|date=2014|doi=10.1051/0004-6361/201322766|volume=565|journal=Astronomy & Astrophysics|page=A56|bibcode=2014A&A...565A..56G}}</ref>

In 2019, Hanuš et al. consolidated 21 selected prior mass estimates, dating from 1992 to 2017, with a metastatistical result of {{val|3.8|1.3|e=19|u=kg}} (that is, {{val|2.5|to|5.1|e=19|u=kg}} to within 1 sigma uncertainty.<ref name="Hanus2019"/>

==Gallery==
<gallery mode="packed" heights="150px">
File:Animation of 704 Interamnia orbit 2000-2020.gif|Animation of 704 Interamnia{{'s}} orbit 2000-2020<br />{{legend2|yellow|Sun}}{{·}}{{legend2| RoyalBlue|Earth}}{{·}}{{legend2|Gold|Mars}}{{·}}{{legend2|Lime|Jupiter}}{{·}}{{legend2|Magenta|704 Interamnia}}
File:TESS observation of Interamnia.gif|The Transiting Exoplanet Survey Satellite (TESS) observed 704 Interamnia passing close to a target star, TIC 14802783, on 18/01/19.
</gallery>

==See also==
*[[List of Solar System objects by size]]

==Notes==
{{notelist}}

==References==
{{reflist|refs=

<ref name=bright2007>{{cite web
 |title      = Bright Minor Planets 2007
 |publisher  = [[Minor Planet Center]]
 |url        = http://www.cfa.harvard.edu/iau/Ephemerides/Bright/2007
 |access-date = 2008-05-21
}}{{Dead link|date=August 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

<ref name=Michalak2001>{{cite journal
 |last=Michalak
 |first=G.
 |title=Determination of asteroid masses
 |journal=Astronomy & Astrophysics
 |volume=374
 |issue=2
 |pages=703–711
 |date=2001
 |doi=10.1051/0004-6361:20010731
 |bibcode=2001A&A...374..703M
|doi-access=free
 }}</ref>

<ref name=Baer>
{{cite web
  |date=2010
  |title=Recent Asteroid Mass Determinations
  |publisher=Personal Website
  |first=James
  |last=Baer
  |url=http://home.earthlink.net/~jimbaer1/astmass.txt
  |access-date=2011-02-13
  |archive-url=https://web.archive.org/web/20130702212735/http://home.earthlink.net/~jimbaer1/astmass.txt
  |archive-date=2013-07-02
  |url-status=dead
  }}
</ref>

<ref name="Hanus2019">{{cite journal
  |display-authors=etal
  |first1=J. |last1=Hanuš
  |first2=P. |last2=Vernazza
  |first3=M. |last3=Viikinkoski
  |first4=M. |last4=Ferrais
  |first5=N. |last5=Rambaux
  |first6=E. |last6=Podlewska-Gaca
  |s2cid=208512707 |title=(704) Interamnia: A transitional object between a dwarf planet and a typical irregular-shaped minor body
  |journal=Astronomy & Astrophysics |year=2020 |volume=633 |pages=A65 |doi=10.1051/0004-6361/201936639 |arxiv=1911.13049
  |bibcode=2020A&A...633A..65H }}</ref>

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

== External links ==
* [http://physics.bgsu.edu/~layden/Anim/Asteroids/interamnia.htm Animation of Asteroid Interamnia] taken on 1 & 2 April 2003
* [http://iota.jhuapl.edu/mp704d17.htm Interamnia Occultations Observed before 2003]
* [http://adsabs.harvard.edu/abs/1997DPS....29.0710B Occultation of GSC 23450183] by {{mp|704 Interamnia}} on 17 December 1996
* [https://web.archive.org/web/20070109172809/http://uchukan.satsumasendai.jp/data/occult/limovie/0303intera-study.html Occultation of HIP36189] by {{mp|704 Interamnia}} on 23 March 2003
* [https://arxiv.org/abs/1911.13049 (704) Interamnia: A transition object between a dwarf planet and a typical irregular-shaped minor body]
* {{AstDys|704}}
* {{JPL small body}}

{{Minor planets navigator |703 Noëmi |number=704 |705 Erminia}}
{{Large asteroids}}
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{{DEFAULTSORT:000704}}
[[Category:Background asteroids]]
[[Category:Discoveries by Vincenzo Cerulli|Interamnia]]
[[Category:Named minor planets|Interamnia]]
[[Category:F-type asteroids (Tholen)]]
[[Category:B-type asteroids (SMASS)]]
[[Category:1910 in science|19101002]]
[[Category:Astronomical objects discovered in 1910|19101002]]
[[Category:Objects observed by stellar occultation]]
[[Category:Possible dwarf planets]]