{{Short description|Dark main-belt asteroid}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1985 Hopmann | background = #D6D6D6 | image = 001985-asteroid shape model (1985) Hopmann.png | image_scale = | caption = Shape of Hopmann modeled from its lightcurve | discovery_ref = <ref name="jpldata" /> | discoverer = K. Reinmuth | discovery_site = Heidelberg Obs. | discovered = 13 January 1929 | mpc_name = (1985) Hopmann | alt_names = 1929 AE{{·}}{{mp|1951 CA|2}}<br />1951 CP{{·}}1952 KE<br />1964 PJ{{·}}{{mp|1973 AA|4}} | pronounced = | named_after = Josef Hopmann<br />{{small|(German astronomer)}}<ref name="springer" /> | mp_category = main-belt{{·}}{{small|(outer)}}<ref name="lcdb" /> | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 88.16 yr (32,201 days) | aphelion = 3.6021 AU | perihelion = 2.6408 AU | semimajor = 3.1214 AU | eccentricity = 0.1540 | period = 5.51 yr (2,014 days) | mean_anomaly = 334.27° | mean_motion = {{Deg2DMS|0.1787|sup=ms}} / day | inclination = 17.159° | asc_node = 305.15° | arg_peri = 234.25° | mean_diameter = 35.47 km {{small|(derived)}}<ref name="lcdb" /><br />{{nowrap|{{val|35.51|3.1}} km {{small|(IRAS:6)}}<ref name="jpldata" />}}<br />{{val|44.33|3.53}} km<ref name="Masiero-2012" /> | rotation = {{val|17.476|0.003|ul=h}}<ref name="Aymami-2012b" /><br />{{val|17.478|0.004}} h<ref name="Moravec-2012" /><br />{{val|17.4787|0.0001}} h<ref name="Durech-2016" /><br />{{val|17.480|0.002}} h<ref name="Stephens-2012d" /> | albedo = {{val|0.039|0.007}} {{small|(IRAS:6)}}<ref name="Masiero-2012" /><br />0.0613 {{small|(derived)}}<ref name="lcdb" /> | spectral_type = C<ref name="lcdb" /> | abs_magnitude = {{val|10.75|0.19}}<ref name="Veres-2015" />{{·}}10.9<ref name="jpldata" /><ref name="lcdb" />{{·}}10.91<ref name="Masiero-2012" /> }}
'''1985 Hopmann''' (''prov. designation'': {{mp|1929 AE}}) is a dark background asteroid in the outer regions of the asteroid belt. It was discovered on 13 January 1929, by astronomer Karl Reinmuth at Landessternwarte Heidelberg-Königstuhl in southern Germany.<ref name="MPC-Hopmann" /> The asteroid has a rotation period of 17.5 hours and measures approximately {{convert|36|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was later named after German astronomer Josef Hopmann (1890–1975).<ref name="springer" />
== Orbit and classification ==
Hopmann is a dark C-type asteroid that orbits the Sun in the outer main-belt at a distance of 2.6–3.6 AU once every 5 years and 6 months (2,014 days). Its orbit has an eccentricity of 0.15 and an inclination of 17° with respect to the ecliptic.<ref name="jpldata" /> The first observation used for the body's observation arc was taken at the discovering observatory on 4 February 1926, or 22 days after its official discovering observation.<ref name="MPC-Hopmann" />
== Naming ==
This minor planet was named in memory of German astronomer Josef Hopmann (1890–1975), a director of Vienna Observatory between 1951 and 1962, a productive observer of variable and binary stars, and a participant in the international program to observe near-Earth asteroid 433 Eros in the early 1930s. The lunar crater Hopmann is also named in his honour.<ref name="springer" /> The official {{MoMP|1985|naming citation}} was published by the Minor Planet Center on 15 October 1977 ({{small|M.P.C. 4237}}).<ref name="DoMP-Circular-dates" />
== Physical characteristics ==
According to the survey carried out by the Infrared Astronomical Satellite IRAS, Hopmann measures 35.51 kilometers in diameter.<ref name="jpldata" /> The Collaborative Asteroid Lightcurve Link agrees with the Supplemental IRAS Minor Planet Survey (SIMPS) data and derives an albedo of 0.039 and a diameter of 35.47 kilometers,<ref name="lcdb" /> while observations with NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission gave an albedo of 0.06 and a diameter of 44.33 kilometers.<ref name="Masiero-2012" />
In January and February 2012, three rotational lightcurves were obtained by Robert Stephens at Santana Observatory ({{small|646}}), California, Josep Maria Aymami at Carmelita Observatory ({{small|B20}}), Barcelona, and Patricia Moravec at Oakley Southern Sky Observatory ({{small|E09}}), Australia. The lightcurves gave a well-defined rotation period of 17.476, 17.478 and 17.480 hours, respectively, with a brightness variation between 0.36 and 0.44 magnitude ({{small|U=3/3/3-}}).<ref name="Aymami-2012b" /><ref name="Moravec-2012" /><ref name="Stephens-2012d" /> In 2016, a re-modeled lightcurve, constructed from data compiled in the Lowell Photometric Database, also gave a concurring period.<ref name="Durech-2016" />
== References == <references>
<ref name="jpldata">{{cite web |type = 2017-03-29 last obs. |title = JPL Small-Body Database Browser: 1985 Hopmann (1929 AE) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001985 |publisher = Jet Propulsion Laboratory |accessdate = 1 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 = (1985) Hopmann |page = [https://archive.org/details/dictionaryminorp00schm/page/n173 160] |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1986}}</ref>
<ref name="MPC-Hopmann">{{cite web |title = 1985 Hopmann (1929 AE) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1985 |accessdate = 25 October 2016}}</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="lcdb">{{cite LCDB|number = 1985 |accessdate = 25 October 2016}}</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= 25 October 2016}}</ref>
<ref name="Stephens-2012d">{{Cite journal |last1 = Stephens |first1 = Robert D. |date = July 2012 |title = Asteroids Observed from GMARS and Santana Observatories: 2012 January - March |journal = Minor Planet Bulletin |url = http://www.minorplanet.info/MPB/issues/MPB_39-3.pdf |volume = 39 |issue = 3 |pages = 181–183 |bibcode = 2012MPBu...39..181S |issn = 1052-8091 |access-date = 17 March 2020 |archive-date = 23 March 2020 |archive-url = https://web.archive.org/web/20200323222606/http://www.minorplanet.info/MPB/issues/MPB_39-3.pdf |url-status = dead }}</ref>
<ref name="Aymami-2012b">{{Cite journal |last1 = Aymami |first1 = Josep Maria |date = July 2012 |title = CCD Photometry and Lightcurve Analysis of Main-Belt Asteroids 14 Irene 4874 Burke, 1985 Hopmann, 3017 Petrovic, and 3070 Aitken from Observatori Carmelita in Tiana |journal = Minor Planet Bulletin |url = http://www.minorplanet.info/MPB/issues/MPB_39-3.pdf |volume = 39 |issue = 3 |pages = 179–181 |bibcode = 2012MPBu...39..179A |issn = 1052-8091 |access-date = 17 March 2020 |archive-date = 23 March 2020 |archive-url = https://web.archive.org/web/20200323222606/http://www.minorplanet.info/MPB/issues/MPB_39-3.pdf |url-status = dead }}</ref>
<ref name="Moravec-2012">{{Cite journal |display-authors = 6 |last1 = Moravec |first1 = Patricia |last2 = Cochren |first2 = Joseph |last3 = Gerhardt |first3 = Michael |last4 = Harris |first4 = Andrew |last5 = Karnemaat |first5 = Ryan |last6 = Melton |first6 = Elizabeth |last7 = Stolze |first7 = Kellen |last8 = West |first8 = Josh |last9 = Ditteon |first9 = Richard |date = October 2012 |title = Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory: 2012 January–April |journal = Minor Planet Bulletin |url = http://www.minorplanet.info/MPB/issues/MPB_39-4.pdf |volume = 39 |issue = 4 |pages = 213–216 |bibcode = 2012MPBu...39..213M |issn = 1052-8091 |access-date= 17 March 2020}}</ref>
<ref name="Durech-2016">{{cite journal |first1 = J. |last1 = Durech |first2 = J. |last2 = Hanus |first3 = D. |last3 = Oszkiewicz |first4 = R. |last4 = Vanco |date = March 2016 |title = Asteroid models from the Lowell photometric database |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016A&A...587A..48D |journal = Astronomy and Astrophysics |volume = 587 |page = 6 |bibcode = 2016A&A...587A..48D |doi = 10.1051/0004-6361/201527573 |arxiv = 1601.02909 |access-date= 25 October 2016}}</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= 25 October 2016}}</ref>
</references> <!-- end of reflist -->
== External links == * [http://www.uni-leipzig.de/unigeschichte/professorenkatalog/leipzig/Hopmann_65/ Prof. Dr. phil. habil. Josef Hopmann], catalogus professorum (Leipzig University) * [http://www.minorplanet.info/PHP/OneAsteroidInfo.php Lightcurve Database Query] (LCDB), at ''www.minorplanet.info'' * [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] – ''Geneva Observatory'', Raoul Behrend * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1985}} * {{JPL small body}}
{{Minor planets navigator |1984 Fedynskij |number=1985 |1986 Plaut}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Hopmann}} 001985 Category:Discoveries by Karl Wilhelm Reinmuth Category:Named minor planets 19290113