View source for Astronomy:(300163) 2006 VW139

{{Short description|Asteroid in the asteroid belt}}
{{DISPLAYTITLE:{{mp|(300163) 2006 VW|139}}}}
{{Infobox planet
 | minorplanet     = yes
 | name            = {{mp|(300163) 2006 VW|139}}<br />288P/{{mp|2006 VW|139}}
 | background      = #D6D6D6
 | image           = 2006VW139.gif
 | image_scale      =
 | caption         = Time-lapse video of {{mp|2006 VW|139}}
 | discovery_ref   = <ref name="jpldata" /><ref name="MPC-object" />
 | discoverer      = [[Astronomy:Spacewatch|Spacewatch]]
 | discovery_site  = [[Astronomy:Kitt Peak National Observatory|Kitt Peak National Obs.]]
 | discovered      = 15 November 2006
 | mpc_name        = (300163) {{mp|2006 VW|139}}
 | alt_names       = {{mp|2006 VW|139}}{{·}}288P<ref name="jpldata" /><br />{{mp|P/2006 VW|139}}<ref name="Hsieh-2012" />
 | pronounced      = 
 | named_after     = <!--xyx-wikiarticle<br />{{small|(description)}}-->
 | mp_category     = main-belt<ref name="jpldata" /><ref name="MPC-object" />{{·}}{{small|([[Astronomy:Kirkwood gap|outer]])}}<ref name="lcdb" /><br />[[Astronomy:Main-belt comet|main-belt comet]]<ref name="Hsieh-2012" /><ref name="Agarwal-2017" />
 | orbit_ref       = <ref name="jpldata" />
 | epoch           = 4 September 2017 ([[Astronomy:Julian day|JD]] 2458000.5)
 | uncertainty     = 0
 | observation_arc = 16.31 yr (5,958 days)
 | aphelion        = 3.6619 [[Astronomy:Astronomical unit|AU]]
 | perihelion      = 2.4358 AU
 | semimajor       = 3.0488 AU
 | eccentricity    = 0.2011
 | period          = 5.32 [[Astronomy:Julian year|yr]] (1,944 days)
 | mean_anomaly    = 55.529[[Degree (angle)|°]]
 | mean_motion     = {{Deg2DMS|0.1851|sup=ms}} / day
 | inclination     = 3.2402°
 | asc_node        = 83.187°
 | arg_peri        = 281.00°
 | satellites      = 1<ref name="Agarwal-2017" /><ref name="johnstonsarchive" />
 | dimensions      = {{val|1.8|0.2}} km {{small|(derived)}}<ref name="johnstonsarchive" /><br />3.20 km {{small|(calculated)}}<ref name="lcdb" />
 | mass            = {{val|6.15|4.85|e=12|u=kg}}<ref name="johnstonsarchive" />{{efn|name=mass-note}}
 | rotation        = 
 | albedo          = 0.057 {{small|(assumed)}}<ref name="lcdb" />
 | spectral_type   = [[Astronomy:C-type asteroid|C]] {{small|(assumed)}}<ref name="lcdb" />
 | abs_magnitude   = 16.2<ref name="jpldata" /><ref name="lcdb" />{{·}}{{val|16.20|0.24}}<ref name="Veres-2015" />
}}

'''{{mp|(300163) 2006 VW|139}}''' ([[Astronomy:Provisional designation|provisional designation]] '''{{mp|2006 VW|139}}''', periodic comet designation '''{{mp|288P/2006 VW|139}}''') is a [[Astronomy:Binary asteroid|binary]] [[Astronomy:Active asteroid|active asteroid]] and [[Astronomy:Main-belt comet|main-belt comet]] from the outer regions of the [[Astronomy:Asteroid belt|asteroid belt]]. The object was discovered by [[Astronomy:Spacewatch|Spacewatch]] in 2006. Its binary nature was confirmed by the [[Astronomy:Hubble Space Telescope|Hubble Space Telescope]] in September 2016.<ref name="Agarwal-2017" /> Both primary and its [[Astronomy:Minor-planet moon|minor-planet moon]] are similar in mass and size, making it a true binary system.<ref name="Agarwal-2017" /> The components are estimated to measure 1.8 kilometers in diameter, orbiting each other at a wide separation of 104 kilometers every 135 days.<ref name="lcdb" /><ref name="johnstonsarchive" /><ref name="NASA-news-hubble" />

== Discovery ==

{{mp|2006 VW|139}} was discovered on 15 November 2006, by the [[Astronomy:Spacewatch|Spacewatch]] survey at [[Astronomy:Kitt Peak National Observatory|Kitt Peak National Observatory]] near Tucson, Arizona.<ref name="MPC-object" /> The possible cometary activity was seen in November 2011 by [[Astronomy:Pan-STARRS|Pan-STARRS]].<ref name="Hsieh-2012" /> Both Spacewatch and Pan-STARRS are asteroid survey projects of NASA's Near Earth Object Observations Program. After the Pan-STARRS observations it was also given a [[Astronomy:Naming of comets#Systematic designations|comet designation]] of {{mp|288P}}.

== Orbit and classification ==

{{mp|2006 VW|139}} is a non-family asteroid of the main-belt's [[Astronomy:Background asteroid|background population]].<ref name="AstDys-object" /> It is both a [[Astronomy:Binary asteroid|binary asteroid]] and a [[Astronomy:Main-belt comet|main-belt comet]], also known as "active asteroid". It orbits the Sun in the [[Astronomy:Kirkwood gap|outer]] main-belt at a distance of 2.4–3.7&nbsp;[[Astronomy:Astronomical unit|AU]] once every 5 years and 4 months (1,944 days; semi-major axis of 3.05&nbsp;AU). Its orbit has an [[Astronomy:Orbital eccentricity|eccentricity]] of 0.20 and an [[Astronomy:Orbital inclination|inclination]] of 3[[Degree (angle)|°]] with respect to the [[Astronomy:Ecliptic|ecliptic]].<ref name="jpldata" />

The body's [[Astronomy:Observation arc|observation arc]] begins on September 2000, with a [[Astronomy:Precovery|precovery]] taken by the [[Astronomy:Sloan Digital Sky Survey|Sloan Digital Sky Survey]] at Apache Point Observatory, New Mexico, more than six years prior to its official discovery observation by Spacewatch at Kitt Peak.<ref name="MPC-object" />

=== First binary main-belt comet ===

{{mp|2006 VW|139}} was first observed by the [[Astronomy:Hubble Space Telescope|Hubble Space Telescope]] (HST) in December 2011.<ref name="Agarwal-2017" /> It was imaged by HST in September 2016, just before it made its closest approach to the Sun and confirmed its binary nature with two asteroids orbiting each other, and revealed ongoing [[Astronomy:Comet|comet]]ary activity.<ref name="NASA-news-hubble" /> This makes the object the first known binary asteroid that is also classified as a main-belt comet.<ref name="NASA-news-hubble" /> The binary is thought to be the result of fission of the precursor caused by [[Astronomy:Yarkovsky–O'Keefe–Radzievskii–Paddack effect|YORP]]-driven spinup.<ref name="Agarwal-2017" />

Observations of the HST revealed ongoing activity in this binary system. The combined features of this binary asteroid - wide separation, near-equal component size, high eccentricity orbit, and comet-like activity also make it unique among the few known binary asteroids that have a wide separation.<ref name="Agarwal-2017" /><ref name="NASA-news-hubble" />

== Physical characteristics ==

=== Diameter albedo and mass ===

{{mp|2006 VW|139}} has a derived diameter of {{val|1.8|0.2}} kilometer.<ref name="johnstonsarchive" /> The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.057 and calculates a diameter of 3.20 kilometers based on an [[Astronomy:Absolute magnitude|absolute magnitude]] of 16.2.<ref name="lcdb" /> The binary system has an estimated mass between {{val|1.3|e=12|ul=kg}} and {{val|1.1|e=13|u=kg}}.<ref name="Agarwal-2017" /> A single component has a derived mass of {{val|6.15|4.85|e=12|u=kg}}.<ref name="johnstonsarchive" />

== Numbering and naming ==

This [[Astronomy:Minor planet|minor planet]] was numbered by the [[Organization:Minor Planet Center|Minor Planet Center]] on 12 October 2011 ({{small|M.P.C. 76600}}).<ref name="MPC-Circulars-Archive" /> As of 2020, it has not been named.<ref name="MPC-object" />

== Notes ==
{{notelist|refs=

{{efn|name=mass-note|1=The mass of the primary component{{val|6.15|4.85|e=12|u=kg}}. The overall mass of the binary system is estimated to be between {{val|1.3|e=12|u=kg}} and {{val|1.1|e=13|u=kg}}.<ref name="Agarwal-2017" />}}

}} <!-- end of notelist -->

== References ==
{{reflist|30em|refs=

<ref name="jpldata">{{cite web
  |type       = 2016-12-26 last obs.
  |title      = JPL Small-Body Database Browser: 300163 (2006 VW139)
  |url        = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2300163
  |publisher  = [[Organization:Jet Propulsion Laboratory|Jet Propulsion Laboratory]]
  |accessdate = 24 November 2017}}</ref>

<ref name="MPC-object">{{cite web
  |title      = (300163) 2006 VW139
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=300163
  |accessdate = 30 September 2020}}</ref>

<ref name="MPC-Circulars-Archive">{{cite web
  |title      = MPC/MPO/MPS Archive
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
  |accessdate = 24 November 2017}}</ref>

<ref name="johnstonsarchive">{{cite web
  |title      = Asteroids with Satellites Database – (300163) 2006 VW139 (= 288P)
  |work       = Johnston's Archive
  |date       = 24 September 2017
  |author     = Johnston, Wm. Robert
  |url        = http://www.johnstonsarchive.net/astro/astmoons/am-300163.html
  |accessdate = 24 November 2017}}</ref>

<ref name="Hsieh-2012">{{Cite journal
  |display-authors = 6
  |first1     = Henry H. |last1 = Hsieh
  |first2     = Bin |last2 = Yang
  |first3     = Nader |last3 = Haghighipour
  |first4     = Heather M. |last4 = Kaluna
  |first5     = Alan |last5 = Fitzsimmons
  |first6     = Larry |last6 = Denneau
  |first7     = Bojan |last7 = Novakovic
  |first8     = Robert |last8 = Jedicke
  |first9     = Richard J. |last9 = Wainscoat
  |first10    = James D. |last10 = Armstrong
  |first11    = Samuel R. |last11 = Duddy
  |first12    = Stephen C. |last12 = Lowry
  |first13    = Chadwick A. |last13 = Trujillo
  |first14    = Marco |last14 = Micheli
  |first15    = Jacqueline V. |last15 = Keane
  |first16    = Laurie |last16 = Urban
  |first17    = Timm |last17 = Riesen
  |first18    = Karen J. |last18 = Meech
  |first19    = Shinsuke |last19 = Abe
  |first20    = Yu-Chi |last20 = Cheng
  |first21    = Wen-Ping |last21 = Chen
  |first22    = Mikael |last22 = Granvik
  |first23    = Tommy |last23 = Grav
  |first24    = Wing-Huen |last24 = Ip
  |first25    = Daisuke |last25 = Kinoshita
  |first26    = Jan |last26 = Kleyna
  |first27    = Pedro |last27 = Lacerda
  |first28    = Tim |last28 = Lister
  |first29    = Andrea |last29 = Milani
  |first30    = David J. |last30 = Tholen
  |first31    = Peter |last31 = Veres
  |first32    = Carey M. |last32 = Lisse
  |first33    = Michael S. |last33 = Kelley
  |first34    = Yanga R. |last34 = Fernández
  |first35    = Bhuwan C. |last35 = Bhatt
  |first36    = Devendra K. |last36 = Sahu
  |first37    = Nick |last37 = Kaiser
  |first38    = K. C. |last38 = Chambers
  |first39    = Klaus W. |last39 = Hodapp
  |first40    = Eugene A. |last40 = Magnier
  |first41    = Paul A. |last41 = Price
  |first42    = John L. |last42 = Tonry
  |date       = March 2012
  |title      = Discovery of Main-belt Comet P/2006 VW139 by Pan-STARRS1
  |journal    = The Astrophysical Journal Letters
  |volume     = 748
  |issue      = 1
  |page       = 7
  |bibcode    = 2012ApJ...748L..15H
  |doi        = 10.1088/2041-8205/748/1/L15
  |arxiv      = 1202.2126
  |s2cid = 8693844 }}</ref>

<ref name="NASA-news-hubble">{{cite web
  |title=Comet or Asteroid? Hubble Discovers that a Unique Object is a Binary
  |publisher  = NASA
  |date       = 20 September 2017
  |url        = https://www.nasa.gov/feature/goddard/2017/hubble-discovers-that-a-unique-object-is-a-binary
  |access-date= 28 July 2018}}</ref>

<ref name="Agarwal-2017">{{Cite journal
  |first1     = Jessica |last1 = Agarwal
  |first2     = David |last2 = Jewitt
  |first3     = Max |last3 = Mutchler
  |first4     = Harold |last4 = Weaver
  |first5     = Stephen |last5 = Larson
  |date       = September 2017
  |title      = A binary main-belt comet
  |journal    = Nature
  |volume     = 549
  |issue      = 7672
  |pages      = 357–359.(NatureHomepage)
  |bibcode    = 2017Natur.549..357A
  |doi        = 10.1038/nature23892
  |pmid = 28933430
 |arxiv      = 1710.03454
  |s2cid = 4469577
 }}</ref>

<ref name="AstDys-object">{{cite web
  |title      = Asteroid (300163) 2006 VW139 – Proper Elements
  |publisher  = AstDyS-2, Asteroids – Dynamic Site
  |url        = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=300163
  |access-date= 28 October 2019}}</ref>

<ref name="lcdb">{{cite web
  |title      = LCDB Data for (300163) 
  |publisher  = Asteroid Lightcurve Database (LCDB)
  |url        = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=300163%7C
  |accessdate = 24 November 2017}}</ref>

<ref name="Veres-2015">{{cite journal
  |display-authors = 6
  |first1     = Peter |last1 = Veres
  |first2     = Robert |last2 = Jedicke
  |first3     = Alan |last3 = Fitzsimmons
  |first4     = Larry |last4 = Denneau
  |first5     = Mikael |last5 = Granvik
  |first6     = Bryce |last6 = Bolin
  |first7     = Serge |last7 = Chastel
  |first8     = Richard J. |last8 = Wainscoat
  |first9     = William S. |last9 = Burgett
  |first10    = Kenneth C. |last10 = Chambers
  |first11    = Heather |last11 = Flewelling
  |first12    = Nick |last12 = Kaiser
  |first13    = Eugen A. |last13 = Magnier
  |first14    = Jeff S. |last14 = Morgan
  |first15    = Paul A. |last15 = Price
  |first16    = John L. |last16 = Tonry
  |first17    = Christopher |last17 = Waters
  |date       = November 2015
  |title      = Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results
  |journal    = Icarus
  |volume     = 261
  |pages      = 34–47
  |bibcode    = 2015Icar..261...34V
  |doi        = 10.1016/j.icarus.2015.08.007
  |arxiv      = 1506.00762
  |s2cid = 53493339 }}</ref>

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

== External links ==
* [http://hubblesite.org/news_release/news/2017-32 Comet or Asteroid? Hubble Discovers that a Unique Object is a Binary], Hubblesite, September 2017
* [http://www.johnstonsarchive.net/astro/asteroidmoons.html Asteroids with Satellites], Robert Johnston, johnstonsarchive.net
* [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/NumberedMPs300001.html Discovery Circumstances: Numbered Minor Planets (300001)-(305000)] – Minor Planet Center
* {{AstDys|300163}}
* {{JPL small body}}

{{Minor planets navigator | |number=300163 |PageName={{mp|(300163) 2006 VW|139}} | }}
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{{DEFAULTSORT:2006 VW139}}
[[Category:Discoveries by the Spacewatch project|300163]]
[[Category:Binary asteroids|300163]]

{{Sourceattribution|(300163) 2006 VW139}}