Editing 128 Nemesis

{{Short description|Main-belt asteroid}}
{{Use dmy dates|date=September 2018}}
{{Infobox planet
 | minorplanet=yes
 | image=128 Nemesis VLT (2021), deconvolved.pdf
 | background=#D6D6D6
 | name=128 Nemesis
 | discovery_ref=<ref name="MPC-object" />
 | discoverer=[[James Craig Watson]]
 | discovered=25 November 1872
 | mpc_name=(128) Nemesis
 | alt_names=A872 WA; {{mp|1952 HW|1}}
 | pronounced={{IPAc-en|ˈ|n|ɛ|m|ᵻ|s|ɪ|s}}<ref>{{OED|Nemesis}}</ref>
 | adjective=Nemesian {{IPAc-en|n|ə|ˈ|m|iː|ʒ|(|i|)|ə|n}}<ref>Hornum (1993) ''Nemesis, the Roman state and the games''</ref><ref>Peery (1963) ''Studies in the Renaissance'', vol. 10</ref>
 | named_after=[[Nemesis (mythology)|Nemesis]]
 | mp_category=[[main-belt]]<ref name="MPC-object" /><ref name=jpldata/>{{·}}[[Nemesis family|Nemesis]]
 | orbit_ref       = <ref name="jpldata" />
 | epoch           = 23 March 2018 ([[Julian day|JD]] 2458200.5)
 | uncertainty     = 0
 | observation_arc = 144.93 [[Julian year (astronomy)|yr]] (52,934 d)
 | aphelion        = {{convert|3.0996|AU|Gm|adj=ri2|2|abbr=on|lk=on}}
 | perihelion      = {{convert|2.3998|AU|Gm|adj=ri2|2|abbr=on}}
 | semimajor       = {{convert|2.7497|AU|Gm|adj=ri2|2|abbr=on}}
 | eccentricity    = 0.1272
 | period          = {{convert|1665|days|years|2|order=flip}}
 | mean_anomaly    = 345.49[[Degree (angle)|°]]
 | mean_motion     = {{Deg2DMS|0.2162|sup=ms}} / day
 | inclination     = 6.2453°
 | asc_node        = 76.243°
 | arg_peri        = 303.82°
 | mean_diameter   = {{val|163|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|162.5|1.3|ul=km}}<ref name="Masiero-2014" /><br />{{val|184.2|5.2|u=km}}<ref name="Carry2012"/>
 | flattening      = 0.17{{efn|1=Flattening derived from the maximum aspect ratio (c/a): <math>f=1-\frac{c}{a}</math>, where (c/a) = {{val|0.83|0.04}}.<ref name=VLT/>}}
 | mass            = {{val|3.4|1.7|e=18|u=kg}}<ref name=VLT/> <br />{{val|6.0|2.6|e=18|ul=kg}}<ref name="Carry2012"/>
 | density         = {{val|1.5|0.8|u=g/cm3}}<ref name=VLT/><br />{{val|1.82|0.79|u=g/cm<sup>3</sup>}}<ref name="Carry2012"/>
 | rotation        = {{Convert|77.81|h|d|abbr=on|lk=on}}<ref name="Scaltriti1979"/><br>{{Convert|38.9325|h|d|abbr=on|lk=on}}<ref name=jpldata/>
 | albedo          = 0.067 (calculated)<ref name=VLT/><br />{{val|0.067|0.005}}<ref name=jpldata/>
 | spectral_type   = [[Tholen classification|Tholen]] {{=}} [[C-type asteroid|C]]<ref name="jpldata" /><br />[[SMASS classification|SMASS]] {{=}} [[C-type asteroid|C]]<ref name="jpldata" />
 | abs_magnitude=7.70<ref name=jpldata/>
}}

'''128 Nemesis''' is a large 180&nbsp;km [[main-belt]] [[asteroid]], of [[carbonate|carbonaceous]] composition. It rotates rather slowly, taking about 78 hours to complete one rotation.<ref name=jpldata/><ref name="Scaltriti1979"/> Nemesis is the largest member of the Nemesian asteroid family bearing its name. It was discovered by [[James Craig Watson|J. C. Watson]] on 25 November 1872,<ref name=jpldata/> and named after [[Nemesis (mythology)|Nemesis]], the goddess of retribution in [[Greek mythology]].

[[file:128 Nemesis (orbit).gif|thumb|left|Diagram of Nemesis's orbit]]
This object is orbiting the [[Sun]] with a [[orbital period|period]] of {{convert|1665|days|years|2|disp=out|abbr=off}} and an [[orbital eccentricity|eccentricity]] (ovalness) of 0.13. The [[orbital plane]] is [[orbital inclination|inclined]] by 6.2° to the [[plane of the ecliptic]]. It is categorized as a [[C-type asteroid]],<ref name="DeMeo2009"/> indicating a primitive [[carbon]]aceous composition. Based on [[IRAS]] data Nemesis is about 188&nbsp;km in diameter and is around the 33rd largest [[Asteroid belt|main-belt]] asteroid,<ref name="jpl-search"/> while [[Wide-field Infrared Survey Explorer|WISE]] measurements yield a size of ~163&nbsp;km.<ref name="Masiero-2014" /> The 77.81‑hour<ref name=Pilcher2015/> [[rotation period]] is the second longest for an asteroid more than 150&nbsp;km in diameter.<ref name="SBDB"/>

Between 2005 and 2021, 128 Nemesis has been observed to [[Occultation|occult]] eight stars.

== Notes ==
{{notelist}}

== References ==
{{reflist|refs=

<ref name="jpldata">{{cite web
  |type       = 2017-10-31 last obs.
  |title      = JPL Small-Body Database Browser: 128 Nemesis
  |url        = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000128
  |publisher  = [[Jet Propulsion Laboratory]]
  |accessdate = 14 September 2018}}</ref>

<ref name="MPC-object">{{cite web
  |title      = 128 Nemesis
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=128
  |accessdate = 14 September 2018}}</ref>

<ref name="Masiero-2014">{{cite journal
  |display-authors = 6
  |first1     = Joseph R. |last1 = Masiero
  |first2     = T. |last2 = Grav
  |first3     = A. K. |last3 = Mainzer
  |first4     = C. R. |last4 = Nugent
  |first5     = J. M. |last5 = Bauer
  |first6     = R. |last6 = Stevenson
  |first7     = S. |last7 = Sonnett
  |date       = August 2014
  |title      = Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos
  |journal    = The Astrophysical Journal
  |volume     = 791
  |issue      = 2
  |page       = 11
  |bibcode    = 2014ApJ...791..121M
  |doi        = 10.1088/0004-637X/791/2/121
  |arxiv      = 1406.6645
  |s2cid = 119293330 }}</ref>

<ref name=Pilcher2015>{{citation
 | title=New Photometric Observations of 128 {{sic|Nemisis|nolink=y}}, 249 Ilse, and 279 Thule
 | last1=Pilcher | first1=Frederick
 | journal=The Minor Planet Bulletin
 | volume=42 | issue=3 | pages=190−192 | date=July 2015
 | bibcode=2015MPBu...42..190P | postscript=. }}</ref>

<ref name="jpl-search">{{cite web
  |title=JPL Small-Body Database Search Engine: asteroids and orbital class (IMB or MBA or OMB) and diameter > 188.1 (km) 
  |publisher=JPL's Solar System Dynamics Group
  |url=http://ssd.jpl.nasa.gov/sbdb_query.cgi?obj_group=all;obj_kind=ast;obj_numbered=all;ast_orbit_class=IMB;ast_orbit_class=MBA;ast_orbit_class=OMB;OBJ_field=0;ORB_field=0;c1_group=OBJ;c1_item=Ap;c1_op=%3E;c1_value=188.1;table_format=HTML;max_rows=500;format_option=comp;c_fields=AcApAiBhBgBjBkBlBiBnBs;.cgifields=format_option;.cgifields=obj_kind;.cgifields=obj_group;.cgifields=obj_numbered;.cgifields=ast_orbit_class;.cgifields=table_format;.cgifields=com_orbit_class&query=1&c_sort=ApA
  |accessdate=2012-04-17}}</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>

<ref name="Scaltriti1979">{{Citation
 | last1     = Scaltriti
 | first1    = F.
 | last2     = Zappala
 | first2    = V.
 | last3     = Schober
 | first3    = H. J.
 | title     = The rotations of 128 Nemesis and 393 Lampetia - The longest known periods to date
 | journal      = Icarus
 | volume    = 37
 | pages      = 133–141
 | date     = January 1979
 | issue = 1
 | doi       = 10.1016/0019-1035(79)90121-0
 | bibcode   = 1979Icar...37..133S
 | postscript= .}}</ref>

<ref name="DeMeo2009">{{Citation
 |last1=DeMeo 
 |first1=Francesca E. 
 |last2=Binzel 
 |first2=Richard P. 
 |last3=Slivan 
 |first3=Stephen M. 
 |last4=Bus 
 |first4=Schelte J. 
 |display-authors=1 
 |title=An extension of the Bus asteroid taxonomy into the near-infrared 
 |journal=Icarus 
 |volume=202 
 |issue=1 
 |pages=160–180 
 |date=July 2009 
 |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 
 |accessdate=2013-04-08 
 |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="SBDB">{{cite web
  |title=JPL Small-Body Database Search Engine: diameter > 150 (km) and rot_per > 24 (h)
  |publisher=[[JPL Solar System Dynamics]]
  |url=http://ssd.jpl.nasa.gov/sbdb_query.cgi?obj_group=all;obj_kind=all;obj_numbered=all;OBJ_field=0;ORB_field=0;combine_mode=AND;c1_group=OBJ;c1_item=Ap;c1_op=%3E;c1_value=150;c2_group=OBJ;c2_item=As;c2_op=%3E;c2_value=24;table_format=HTML;max_rows=50;format_option=comp;c_fields=AcBhBgBjBiBnBsAiApAs;.cgifields=format_option;.cgifields=ast_orbit_class;.cgifields=combine_mode;.cgifields=table_format;.cgifields=obj_kind;.cgifields=obj_group;.cgifields=obj_numbered;.cgifields=com_orbit_class&query=1&c_sort=AsD
  |accessdate=2015-06-06}}</ref>

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

== External links ==
* {{AstDys|128}}
* {{JPL small body}}
* {{YouTube|0_GTC15PvJ8|Nemesis found! (2013)}} <!-- the team at [[ASAS-SN]] has a sense of humor -->

{{Minor planets navigator |127 Johanna |number=128 |129 Antigone}}
{{Small Solar System bodies}}
{{Authority control}}

{{DEFAULTSORT:Nemesis}}
[[Category:Nemesis asteroids|000128]]
[[Category:Discoveries by James Craig Watson]]
[[Category:Named minor planets]]
[[Category:C-type asteroids (Tholen)|000128]]
[[Category:C-type asteroids (SMASS)|000128]]
[[Category:Astronomical objects discovered in 1872|18721125]]