View source for 164 Eva

{{Short description|Main-belt asteroid}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
| minorplanet=yes
| background=#D6D6D6
| name=164 Eva
|image= 000164-asteroid shape model (164) Eva.png
|caption= 3D convex shape model of 164 Eva
| discovery_ref=
| discoverer=[[Paul Henry (astronomer)|P. P. Henry]]
| discovery_site=[[Paris]]
| discovered=12 July 1876
| mpc_name=(164) Eva
| alt_names=A876 NA
| pronounced={{IPAc-en|'|iː|v|ə}}<ref>{{dict.com|Eva}}</ref>
| named_after=Unknown
| mp_category=[[Asteroid belt|Main belt]]
| orbit_ref=<ref name="JPL"/>
| epoch=31 July 2016 ([[Julian day|JD]] 2457600.5)
| semimajor={{Convert|2.6338|AU|Gm|abbr=on}}
| perihelion={{Convert|1.7188|AU|Gm|abbr=on}}
| aphelion={{Convert|3.5444|AU|Gm|abbr=on|lk=on}}
| eccentricity=0.34577
| period=4.27 [[Julian year (astronomy)|yr]] (1561.2 [[Julian year (astronomy)|d]])
| inclination=24.4564°
| asc_node=76.8519°
| arg_peri=283.9561°
| mean_anomaly=219.5472[[Degree (angle)|°]]
| avg_speed=
| dimensions={{val|104.87|1.9|ul=km}}<ref name="JPL"/><br />101.77 ± 3.61 km<ref name="Carry2012"/>
| mass={{nowrap|(9.29 ± 7.76) × 10<sup>17</sup> kg<ref name="Carry2012"/>}}
| density=1.68 ± 1.41 g/cm<sup>3</sup><ref name="Carry2012"/>
| surface_grav=2.249 cm/s (mean)
| escape_velocity=4.857 cm/s (mean)
| rotation={{Convert|13.66|h|d|abbr=on|lk=on}}<ref name="JPL"/><br />13.672 h<ref name="Warner2009"/>
| spectral_type=[[C-type asteroid|C]]
| magnitude=
| abs_magnitude=8.89,<ref name="JPL"/> 8.84<ref name="Warner2007"/>
| albedo={{val|0.0447|0.002}}
| single_temperature=170 K (mean)
| mean_motion={{Deg2DMS|0.230591|sup=ms}} / day
| observation_arc=118.93 yr (43438 d)
| uncertainty=0
| moid={{Convert|0.882286|AU|Gm|abbr=on}}
| jupiter_moid={{Convert|2.44116|AU|Gm|abbr=on}}
| tisserand=3.191
}}
'''164 Eva''' is a [[Asteroid belt|main-belt]] [[asteroid]] that was discovered by the French brothers [[Paul Henry and Prosper Henry]] on July 12, 1876, in Paris. The reason the name Eva was chosen remains unknown, though [[Karl Ludwig Littrow]] suspected a "worldly origin" (''"Mit dem Namen könnten wir wie bei [[102 Miriam|Miriam]] wieder den biblischen Boden zu betreten glauben, wenn wir bei diesem Entdecker nicht an Taufen weltlichen Ursprungs gewöhnt wären"'').<ref name="Schmadel2012"/> The [[orbital elements]] for 164 Eva were published in 1877 by American astronomer [[Winslow Upton]].<ref name="Upton1877"/> It is categorized as a [[C-type asteroid]] and is probably composed of primitive [[carbonate|carbonaceous]] [[chondrite|chondritic]] materials.
[[Photometry (astronomy)|Photometric]] observations of this asteroid at the Palmer Divide Observatory in [[Colorado Springs, Colorado]], during 2008 gave a [[light curve]] with a period of 13.672 ± 0.003 hours and a small brightness variation of 0.04 ± 0.01 in [[Magnitude (astronomy)|magnitude]]. This is consistent with a previous study reported in 1982 that listed a period estimate of 13.66 hours.<ref name="Warner2009"/>
Between 2000 and 2021, 164 Eva has been observed to [[occultation|occult]] fourteen stars.
With a perihelion of 1.718 AU 164 Eva is the closest asteroid over 100 kilometers to approach the [[orbit of Mars]]. Its closest approach is about 0.05 AU or about 19.5 lunar distances.<ref>[https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=164 NASA.gov]</ref>
==References==
{{Reflist|refs=
<ref name="JPL">{{Citation
| first1    = Donald K.
| last1     = Yeomans
| title     = 164 Eva
| work      = JPL Small-Body Database
| url       = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=164
| archive-url = https://web.archive.org/web/20190304133020/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=164
| url-status = dead
| archive-date = 4 March 2019
| accessdate= 12 May 2016
| postscript= .}}</ref>
<ref name="Upton1877">{{Citation
| last1     = Upton
| first1    = Winslow
| title     = Elements of (164) Eva
| journal      = Astronomische Nachrichten
| volume    = 90
| issue = 6
| pages     = 85–86
|date=July 1877
| doi       = 10.1002/asna.18770900605
| bibcode   = 1877AN.....90...85U
| postscript= .| url = https://zenodo.org/record/1424701
}}</ref>
<ref name="Carry2012">{{Citation
| first1    = B.
| last1     = Carry
| title     = Density of asteroids
| journal      = Planetary and Space Science
| volume    = 73
| issue = 1
| pages      = 98–118
|date=December 2012
| doi       = 10.1016/j.pss.2012.03.009
| bibcode   = 2012P&SS...73...98C
| postscript= .
|arxiv = 1203.4336}} See Table 1.</ref>
<ref name="Warner2007">{{Citation
| last1     = Warner
| first1    = Brian D.
| title     = Initial Results of a Dedicated H-G Project
| journal      = The Minor Planet Bulletin
| volume    = 34
| issue = 4
| pages     = 113–119
|date=December 2007
| bibcode   = 2007MPBu...34..113W
| postscript= .}}</ref>
<ref name="Schmadel2012">{{Citation
| first1    = Lutz D.
| last1     = Schmadel
| title     = Dictionary of Minor Planet Names
| publisher = Springer
| pages      = 28, 1341
| year      = 2012
| isbn      = 978-3642297182
| url       = https://books.google.com/books?id=aeAg1X7afOoC&pg=PA1341 | postscript= .}}</ref>
<ref name="Warner2009">{{Citation
| last1     = Warner
| first1    = Brian D.
| title     = Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 May - September
| journal      = The Minor Planet Bulletin
| volume    = 36
| issue     = 1
| pages     = 7–13
|date=January 2009
| bibcode   = 2009MPBu...36....7W
| postscript= .}}</ref>
}} <!-- end of reflist -->
== External links ==
* [http://www.minorplanetobserver.com/pdolc/A164_2008.HTM Lightcurve plot of 164 Eva], Palmer Divide Observatory, ''[[Brian D. Warner|B. D. Warner]]'' (2008)
* [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 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/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
* {{AstDys|164}}
* {{JPL small body}}
{{Minor planets navigator |163 Erigone |number=164 |165 Loreley}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:000164}}
[[Category:Background asteroids]]
[[Category:Discoveries by Paul Henry and Prosper Henry|Eva]]
[[Category:Named minor planets|Eva]]
[[Category:CX-type asteroids (Tholen)]]
[[Category:X-type asteroids (SMASS)]]
[[Category:Astronomical objects discovered in 1876|18760712]]
[[Category:Objects observed by stellar occultation]]
{{C-beltasteroid-stub}}