{{Short description|Stony main-belt asteroid}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1957 Angara | background = #D6D6D6 | image = 001957-asteroid shape model (1957) Angara.png | image_scale = | caption = Modelled shape of Angara from its lightcurve | discovery_ref = <ref name="jpldata" /> | discovered = 1 April 1970 | discoverer = L. Chernykh | discovery_site = {{nowrap|Crimean Astrophysical Obs.}} | mpc_name = (1957) Angara | alt_names = 1970 GF{{·}}{{mp|1962 WG|1}}<br />1969 AA | pronounced = | named_after = Angara River<br />{{small|(Siberian river)}}<ref name="springer" /> | mp_category = main-belt{{·}}Eos<ref name="lcdb" /> | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 60.58 yr (22,126 days) | aphelion = 3.1828 AU | perihelion = 2.8338 AU | semimajor = 3.0083 AU | eccentricity = 0.0580 | period = 5.22 yr (1,906 days) | mean_anomaly = 345.36° | mean_motion = {{Deg2DMS|0.1889|sup=ms}} / day | inclination = 11.191° | asc_node = 50.702° | arg_peri = 209.03° | dimensions = {{val|17.907|0.108}} km<ref name="Masiero-2011" /><br />{{val|18.189|0.229}} km<ref name="WISE" /><br />18.38 km {{small|(derived)}}<ref name="lcdb" /><br />{{val|21.44|0.70}} km<ref name="AKARI" /><br />{{val|30.41|0.58}} km<ref name="Masiero-2012" /> | rotation = {{val|3.67|ul=h}}<ref name="Binzel-1987b" /> | albedo = {{val|0.055|0.006}}<ref name="Masiero-2012" /><br />{{val|0.111|0.008}}<ref name="AKARI" /><br />0.14 {{small|(assumed)}}<ref name="lcdb" /><br />{{val|0.1438|0.0310}}<ref name="WISE" /> | spectral_type = S<ref name="lcdb" /><ref name="Binzel-1987b" /><br />B–V = 0.900<ref name="jpldata" /><br />U–B = 0.380<ref name="jpldata" /> | abs_magnitude = {{val|11.16|0.34}}<ref name="Veres-2015" />{{·}}11.36<ref name="jpldata" /><ref name="AKARI" /><ref name="Masiero-2012" />{{·}}11.43<ref name="lcdb" /><ref name="WISE" /><ref name="Binzel-1987b" /> }}
'''1957 Angara''' (''prov. designation'': {{mp|1970 GF}}) is a stony Eos asteroid from the outer regions of the asteroid belt, approximately {{convert|18|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 1 April 1970, by Soviet astronomer Lyudmila Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, and named after the Siberian Angara River.<ref name="springer" /><ref name="MPC-Angara" />
== Classification and orbit ==
Angara is a member of the Eos family, well known for mostly being of a silicaceous composition. It orbits the Sun in the outer main-belt at a distance of 2.8–3.2 AU once every 5 years and 3 months (1,906 days). Its orbit has an eccentricity of 0.06 and an inclination of 11° with respect to the ecliptic.<ref name="jpldata" /> A first precovery was taken at Goethe Link Observatory in 1956, extending the body's observation arc by 14 years prior to its official discovery observation at Nauchnyj.<ref name="MPC-Angara" />
== Naming ==
This minor planet was named for the over 1000-mile long Siberian Angara River that drains Lake Baikal.<ref name="springer" /> The official {{MoMP|1957|naming citation}} was published by the Minor Planet Center on 30 June 1977 ({{small|M.P.C. 4190}}).<ref name="DoMP-Circular-dates" />
== Physical characteristics ==
In December 1983, a rotational lightcurve of Angara was obtained from photometric observations by American astronomer Richard Binzel. Lightcurve analysis gave a well-define rotation period of 3.67 hours with a brightness amplitude of 0.52 magnitude, indicative of a non-spheroidal shape ({{small|U=3}}).<ref name="Binzel-1987b" /> Binzel also classified the body as a stony S-type asteroid.<ref name="Binzel-1987b" />
According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Angara measures between 17.907 and 30.41 kilometers in diameter and its surface has an albedo between 0.055 and 0.1438.<ref name="Masiero-2011" /><ref name="WISE" /><ref name="AKARI" /><ref name="Masiero-2012" /> The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony Eoan asteroids of 0.14 – taken from the family's largest member and namesake, 221 Eos – and derives a diameter of 18.38 kilometers with an absolute magnitude of 11.43.<ref name="lcdb" />
== References == <references>
<ref name="jpldata">{{cite web |type = 2017-06-02 last obs. |title = JPL Small-Body Database Browser: 1957 Angara (1970 GF) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001957 |publisher = Jet Propulsion Laboratory |access-date = 2 July 2017}}</ref>
<ref name="springer">{{cite book |title = Dictionary of Minor Planet Names |url = https://archive.org/details/dictionaryminorp00schm |url-access = limited |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |chapter = (1957) Angara |page = [https://archive.org/details/dictionaryminorp00schm/page/n170 157] |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1958}}</ref>
<ref name="MPC-Angara">{{cite web |title = 1957 Angara (1970 GF) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1957 |access-date = 4 April 2017}}</ref>
<ref name="DoMP-Circular-dates">{{cite book |title = Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) |year = 2009 |url = https://archive.org/details/dictionaryminorp2008schm |url-access = limited |chapter = Appendix – Publication Dates of the MPCs |last = Schmadel |first=Lutz D. |publisher = Springer Berlin Heidelberg |page = [https://archive.org/details/dictionaryminorp2008schm/page/n230 221] |isbn = 978-3-642-01964-7 |doi = 10.1007/978-3-642-01965-4}}</ref>
<ref name="Masiero-2011">{{cite journal |display-authors = 6 |first1 = Joseph R. |last1 = Masiero |first2 = A. K. |last2 = Mainzer |first3 = T. |last3 = Grav |first4 = J. M. |last4 = Bauer |first5 = R. M. |last5 = Cutri |first6 = J. |last6 = Dailey |first7 = P. R. M. |last7 = Eisenhardt |first8 = R. S. |last8 = McMillan |first9 = T. B. |last9 = Spahr |first10 = M. F. |last10 = Skrutskie |first11 = D. |last11 = Tholen |first12 = R. G. |last12 = Walker |first13 = E. L. |last13 = Wright |first14 = E. |last14 = DeBaun |first15 = D. |last15 = Elsbury |first16 = T. IV |last16 = Gautier |first17 = S. |last17 = Gomillion |first18 = A. |last18 = Wilkins |date = November 2011 |title = Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M |journal = The Astrophysical Journal |volume = 741 |issue = 2 |page = 20 |bibcode = 2011ApJ...741...68M |doi = 10.1088/0004-637X/741/2/68 |arxiv = 1109.4096 |access-date= 4 April 2017}}</ref>
<ref name="lcdb">{{cite LCDB|number = 1957 |access-date = 4 April 2017}}</ref>
<ref name="AKARI">{{cite journal |display-authors = 6 |first1 = Fumihiko |last1 = Usui |first2 = Daisuke |last2 = Kuroda |first3 = Thomas G. |last3 = Müller |first4 = Sunao |last4 = Hasegawa |first5 = Masateru |last5 = Ishiguro |first6 = Takafumi |last6 = Ootsubo |first7 = Daisuke |last7 = Ishihara |first8 = Hirokazu |last8 = Kataza |first9 = Satoshi |last9 = Takita |first10 = Shinki |last10 = Oyabu |first11 = Munetaka |last11 = Ueno |first12 = Hideo |last12 = Matsuhara |first13 = Takashi |last13 = Onaka |date = October 2011 |title = Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey |journal = Publications of the Astronomical Society of Japan |volume = 63 |issue = 5 |pages = 1117–1138 |bibcode = 2011PASJ...63.1117U |doi = 10.1093/pasj/63.5.1117 |doi-access= free }} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-source=J/PASJ/63/1117/acua_v1&Num=1957 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])</ref>
<ref name="WISE">{{cite journal |display-authors = 6 |first1 = A. |last1 = Mainzer |first2 = T. |last2 = Grav |first3 = J. |last3 = Masiero |first4 = E. |last4 = Hand |first5 = J. |last5 = Bauer |first6 = D. |last6 = Tholen |first7 = R. S. |last7 = McMillan |first8 = T. |last8 = Spahr |first9 = R. M. |last9 = Cutri |first10 = E. |last10 = Wright |first11 = J. |last11 = Watkins |first12 = W. |last12 = Mo |first13 = C. |last13 = Maleszewski |date = November 2011 |title = NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results |journal = The Astrophysical Journal |volume = 741 |issue = 2 |page = 25 |bibcode = 2011ApJ...741...90M |doi = 10.1088/0004-637X/741/2/90 |arxiv = 1109.6407}}</ref>
<ref name="Masiero-2012">{{cite journal |display-authors = 6 |first1 = Joseph R. |last1 = Masiero |first2 = A. K. |last2 = Mainzer |first3 = T. |last3 = Grav |first4 = J. M. |last4 = Bauer |first5 = R. M. |last5 = Cutri |first6 = C. |last6 = Nugent |first7 = M. S. |last7 = Cabrera |date = November 2012 |title = Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M |journal = The Astrophysical Journal Letters |volume = 759 |issue = 1 |page = 5 |bibcode = 2012ApJ...759L...8M |doi = 10.1088/2041-8205/759/1/L8 |arxiv = 1209.5794 |access-date= 4 April 2017}}</ref>
<ref name="Binzel-1987b">{{Cite journal |author = Binzel, R. P. |date = October 1987 |title = A photoelectric survey of 130 asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1987Icar...72..135B |journal = Icarus |volume = 72 |issue = 1 |pages = 135–208 |issn = 0019-1035 |bibcode = 1987Icar...72..135B |doi = 10.1016/0019-1035(87)90125-4 |access-date= 4 April 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 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V |journal = Icarus |volume = 261 |pages = 34–47 |bibcode = 2015Icar..261...34V |doi = 10.1016/j.icarus.2015.08.007 |arxiv = 1506.00762 |access-date= 4 April 2017}}</ref>
</references> <!-- end of reflist -->
== External links == * [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/20110721225144/http://www.minorplanet.info/lightcurvedatabase.html |date=21 July 2011 }}) * [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/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1957}} * {{JPL small body}}
{{Minor planets navigator|1956 Artek|number=1957|1958 Chandra}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Angara}} 001957 Category:Discoveries by Lyudmila Chernykh Category:Named minor planets 19700401