View source for (721708) 2004 BX159

{{Short description|Asteroid}}
{{DISPLAYTITLE:{{mp|(721708) 2004 BX|159}}}}
{{Infobox planet
| minorplanet     = yes
| name            = {{mp|(721708) 2004 BX|159}}
| background      = #D6D6D6
| image           =
| caption         =
| discovery_ref   = <ref name="jpldata" /><ref name="MPC-2004BX159" />
| discovered      = 20 January 2004<br />{{nowrap|{{small|(discovery: first observation only)}}}}
| discoverer      = [[Paranal Observatory|Paranal Obs.]]
| discovery_site  = [[Paranal Observatory|Paranal Obs.]]
| mpc_name        = {{mp|2004 BX|159}}
| alt_names       =
| named_after     =
| mp_category     = [[main-belt]]<ref name="jpldata" /><ref name="MPC-2004BX159" />{{·}}{{small|([[Kirkwood gap|middle]])}}
| orbit_ref       = <ref name="jpldata" />
| epoch           = 4 September 2017 ([[Julian day|JD]] 2458000.5)
| uncertainty     = 0
| observation_arc = 19.97 yr (7,293 days)
|earliest_precovery_date = 14 July 1997
| aphelion        = 2.8997 [[Astronomical unit|AU]]
| perihelion      = 2.1632 AU
| semimajor       = 2.5315 AU
| eccentricity    = 0.1455
| period          = 4.03 [[Julian year (astronomy)|yr]] (1,471 days)
| mean_anomaly    = 355.95[[Degree (angle)|°]]
| mean_motion     = {{Deg2DMS|0.2447|sup=ms}} / day
| inclination     = 4.0931°
| asc_node        = 159.75°
| arg_peri        = 153.29°
| dimensions      = 1.2 km {{small|(estimate)}}<ref name="Risk-Summary-140401" /><br />1.8 km {{small|(est. at [[Astronomical albedo|0.10]])}}<ref name="h" />
| rotation        =
| albedo          =
| spectral_type   =
| abs_magnitude   = 16.9<ref name="jpldata" />
}}
'''{{mp|(721708) 2004 BX|159}}''' is an [[asteroid]] from the central region of the [[asteroid belt]], approximately 1.2 kilometers in diameter. It was first observed at [[Paranal Observatory]] in the Atacama desert of Chile on 20 January 2004.<ref name="MPC-2004BX159" /> {{mp|2004 BX|159}} missed the virtual impactor date of 29 August 2009.<ref name="Risk-Summary-070218"/> The asteroid was removed from the [[Sentry (monitoring system)|Sentry Risk Table]] in April 2014<ref name=removed/> as a result of [[precovery]] images establishing it is a harmless main belt asteroid.
== Description ==
{{mp|2004 BX|159}} orbits the Sun in the [[Kirkwood gap|central]] main-belt at a distance of 2.2–2.9&nbsp;[[Astronomical unit|AU]] once every 4.03 years (1,471 days). Its orbit has an [[orbital eccentricity|eccentricity]] of 0.15 and an [[orbital inclination|inclination]] of 4[[Degree (angle)|°]] with respect to the [[ecliptic]].<ref name="jpldata" />
After discovery, it was thought to be a [[Mars-crossing asteroid]] because of its poorly known orbit, and was listed on the [[Sentry (monitoring system)|Sentry Risk Table]] as a possible impactor.<ref name="Risk-Summary-070218" /> With an [[observation arc]] of 3 days and only 8 observations, [[perihelion]] was determined to be {{val|1.5|3}} [[astronomical unit]]s (AU).<ref name=JPL2011/>
[[Precovery]] observations in archival data of the [[Canada-France-Hawaii Telescope]] on [[Mauna Kea Observatories|Mauna Kea]] were identified in early 2014, resulting in a dramatic improvement of the orbital accuracy, sufficient to recognize the object as a regular [[Asteroid belt|main belt asteroid]], not posing any danger to Earth.<ref name="jpldata"/>
The body was subsequently linked by the [[Minor Planet Center]] with additional observations reported since 1997. It has now a well-established orbit, observed over decades, with the lowest possible [[Uncertainty parameter|uncertainty of 0]].<ref name="jpldata"/>
It is even known that {{mp|2004 BX|159}} passed {{convert|0.0036|AU|km mi|abbr=on}} from asteroid [[3 Juno]] on 18 September 1961.<ref name="jpldata"/>
== See also ==
* {{mpl|2010 GZ|60}}
== References ==
{{reflist|refs=
<ref name="jpldata">{{cite web
|type       = 2017-07-02 last obs.
|title      = JPL Small-Body Database Browser: (2004 BX159)
|url        = http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3250627;cad=1
|publisher  = [[Jet Propulsion Laboratory]]
|accessdate = 3 August 2017}}</ref>
<ref name="MPC-2004BX159">{{cite web
|title      = 2004 BX159
|work       = Minor Planet Center
|url        = http://www.minorplanetcenter.net/db_search/show_object?object_id=2004+BX159
|accessdate = 3 August 2017}}</ref>
<ref name="Risk-Summary-070218">{{cite web
|date=18 February 2007 |title=WayBack Machine archive from 18 Feb 2007
|publisher=Wayback Machine
|url=http://neo.jpl.nasa.gov/risk/2004bx159.html
|archiveurl=https://web.archive.org/web/20070218092947/http://neo.jpl.nasa.gov/risk/2004bx159.html
|url-status=dead
|archivedate=18 February 2007 }}</ref>
<ref name="Risk-Summary-140401">{{cite web
|date=1 April 2014
|origyear=computed on 2011-09-14
|title=Asteroid 2004 BX159 Impact Risk
|publisher=Wayback Machine: NASA/JPL Near-Earth Object Program Office
|url=http://neo.jpl.nasa.gov/risk/2004bx159.html
|url-status=dead
|archiveurl=https://web.archive.org/web/20140401144737/http://neo.jpl.nasa.gov/risk/2004bx159.html
|archivedate=1 April 2014 }}</ref>
<ref name="h">{{cite web
|title      = Asteroid Size Estimator
|publisher  = CNEOS/JPL
|url        = https://cneos.jpl.nasa.gov/tools/ast_size_est.html
|access-date= 2 August 2017}}</ref>
<ref name=JPL2011>JPL solution 3 (solution date 2011-Sep-14) {{Cite web |url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2004BX159 |title=(2004 BX159) |access-date=8 March 2019 |archive-url=https://archive.today/20121213172810/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2004BX159 |archive-date=13 December 2012 |url-status=dead  }}</ref>
<ref name=removed>Removed Objects {{Cite web |url=http://neo.jpl.nasa.gov/risk/removed.html |title=Near Earth Object Program |access-date=2 March 2018 |archive-url=https://web.archive.org/web/20140403151020/http://neo.jpl.nasa.gov/risk/removed.html |archive-date=3 April 2014 |url-status=dead  }}</ref>
}} <!-- end of reflist -->
== External links ==
* [http://www.hohmanntransfer.com/news/crt04obj.htm#2004bx159 2004 BX159] – hohmanntransfer
* {{AstDys|2004BX159}}
* {{ESA-SSA|2004BX159}}
* {{JPL small body|id=3250627}}
{{Use dmy dates|date=September 2019}}
{{Minor planets navigator | |number=721708 |PageName={{mp|(721708) 2004 BX|159}} | }}
{{Small Solar System bodies}}
{{DEFAULTSORT:721708}}
[[Category:Main-belt asteroids]]
[[Category:Near-Earth objects removed from the Sentry Risk Table]]
[[Category:Astronomical objects discovered in 2004|20040120]]