3102 Krok
{{Short description|Rare-type asteroid and slow rotator}}
{{Use dmy dates|date=April 2018}}
{{Infobox planet
| minorplanet = yes
| name = 3102 Krok
| background = #FFC2E0
| image =
| caption =
| discovered = 21 August 1981
| discoverer = L. Brožek
| discovery_site = Kleť Obs.
| mpc_name = (3102) Krok
| alt_names = 1981 QA
| pronounced =
| named_after = Duke Krok
{{small|(legendary Czech figure)}}
| epoch = 16 February 2017 (JD 2457800.5)
| uncertainty = 0
| observation_arc = 35.44 yr (12,944 days)
| aphelion = 3.1174 AU
| perihelion = 1.1839 AU
| semimajor = 2.1506 AU
| eccentricity = 0.4495
| period = 3.15 yr (1,152 days)
| mean_anomaly = 86.843°
| mean_motion = {{Deg2DMS|0.3125|sup=ms}} / day
| inclination = 8.4439°
| asc_node = 172.09°
| arg_peri = 154.78°
| moid = 0.1840 AU{{·}}71.7 LD
| dimensions = 1.48 km {{small|(derived)}}
1.6 km
| rotation = {{val|147.8|0.3}} h
{{val|149.4|1}} h
{{val|151.8}}
| albedo = 0.20 {{small|(assumed)}}
| spectral_type = QRS {{small|(Tholen)}}
S {{small|(SMASS)}}
Sqw{{·}}QRS
B–V = 0.834
U–B = 0.521
| abs_magnitude = {{val|16.14|0.2}} {{small|(R)}}{{·}}16.2{{·}}{{val|16.40|0.15}}{{·}}{{val|16.47|0.35}}{{·}}{{val|16.524|0.15}}
}}
3102 Krok, provisional designation {{mp|1981 QA}}, is a rare-type asteroid and slow rotator, classified as a near-Earth object of the Amor group, that measures approximately 1.5 kilometers in diameter.
It was discovered on 21 August 1981, by Slovak astronomer Ladislav Brožek at Kleť Observatory in the Czech Republic. The asteroid was named after Duke Krok, a legendary Czech figure.
Classification and orbit
Krok orbits the Sun at a distance of 1.2–3.1 AU once every 3 years and 2 months (1,152 days). Its orbit has an eccentricity of 0.45 and an inclination of 8° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Klet, as no precoveries were taken and no prior identifications were made.
It has an Earth minimum orbital intersection distance of {{convert|0.1840|AU|km|abbr=on|lk=off|sigfig=3}}, which translates into 71.7 lunar distances.
Physical characteristics
In the Tholen classification, Krok is characterized as a rare QRS-type. In the SMASS taxonomy it is classified as a common S-type asteroid, and the "ExploreNEOs" Warm Spitzer program assigns a transitional Sqw-type. The R- and Q-types also belong to the larger group of stony asteroids.
= Rotation and shape =
In September 1991, a first rotational lightcurve of Krok was obtained by American astronomer Alan Harris. Lightcurve analysis gave an exceptionally long rotation period of 147.8 hours with a brightness amplitude of 1.0 magnitude, which indicates that the body has a non-spheroidal shape ({{small|U=3}}).
Between 2000 and 2005, several photometric observations made by Czech astronomer Petr Pravec gave a similar period between 149.4 and 151.8 and an amplitude of 0.7 to 1.3 ({{small|U=3/3-}}). This makes Krok as slow rotator.
= Diameter and albedo =
According to Tom Gehrels{{'}} 1994 publication "Hazards due to Comets and Asteroids", Krok measures 1.6 kilometers in diameter based on a generic surface albedo of 0.15, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony S-type asteroids of 0.20 and calculates a diameter of 1.48 kilometers with an absolute magnitude of 16.5.
Naming
This minor planet was named after Duke Krok, a legendary figure in Czech history, and the first judge ("duke") of the Slavonic tribes in ancient Bohemia. He was also the father of Princess Libuše, who, together with her husband Přemysl founded the Přemyslid dynasty of Czech royalty. The official naming citation was published on 18 December 1994 ({{small|M.P.C. {{MoMP|3102|24410}}}}).
References
{{reflist|30em|refs=
|type = 2017-01-28 last obs.
|title = JPL Small-Body Database Browser: 3102 Krok (1981 QA)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2003102
|publisher = Jet Propulsion Laboratory
|access-date = 25 April 2017}}
|title = Dictionary of Minor Planet Names – (3102) Krok
|last = Schmadel | first = Lutz D.
|publisher = Springer Berlin Heidelberg
|page = 256
|date = 2007
|isbn = 978-3-540-00238-3
|doi = 10.1007/978-3-540-29925-7_3103 |chapter = (3102) Krok }}
|title = 3102 Krok (1981 QA)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=3102
|access-date = 25 April 2017}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|access-date = 25 April 2017}}
|title = LCDB Data for (3102) Krok
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=3102%7CKrok
|access-date = 25 April 2017}}
|first1 = A. W. |last1 = Harris
|first2 = J. W. |last2 = Young
|first3 = Thor |last3 = Dockweiler
|first4 = J. |last4 = Gibson
|first5 = M. |last5 = Poutanen
|first6 = E. |last6 = Bowell
|date = January 1992
|title = Asteroid lightcurve observations from 1981
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1992Icar...95..115H
|journal = Icarus
|volume = 95
|issue = 1
|pages = 115–147.ResearchsupportedbyLowellObservatoryEndowmentandNASA
|issn = 0019-1035
|bibcode = 1992Icar...95..115H
|doi = 10.1016/0019-1035(92)90195-D
|access-date= 25 April 2017}}
|display-authors = 6
|first1 = P. |last1 = Pravec
|first2 = A. W. |last2 = Harris
|first3 = P. |last3 = Scheirich
|first4 = P. |last4 = Kusnirák
|first5 = L. |last5 = Sarounová
|first6 = C. W. |last6 = Hergenrother
|first7 = S. |last7 = Mottola
|first8 = M. D. |last8 = Hicks
|first9 = G. |last9 = Masi
|first10 = Yu. N. |last10 = Krugly
|first11 = V. G. |last11 = Shevchenko
|first12 = M. C. |last12 = Nolan
|first13 = E. S. |last13 = Howell
|first14 = M. |last14 = Kaasalainen
|first15 = A. |last15 = Galád
|first16 = P. |last16 = Brown
|first17 = D. R. |last17 = DeGraff
|first18 = J. V. |last18 = Lambert
|first19 = W. R. |last19 = Cooney
|first20 = S. |last20 = Foglia
|date = January 2005
|title = Tumbling asteroids
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2005Icar..173..108P
|journal = Icarus
|volume = 173
|issue = 1
|pages = 108–131
|bibcode = 2005Icar..173..108P
|doi = 10.1016/j.icarus.2004.07.021
|access-date= 25 April 2017}}
|first1 = Petr |last1 = Pravec
|first2 = Alan W. |last2 = Harris
|first3 = Peter |last3 = Kusnirák
|first4 = Adrián |last4 = Galád
|first5 = Kamil |last5 = Hornoch
|date = September 2012
|title = Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012Icar..221..365P
|journal = Icarus
|volume = 221
|issue = 1
|pages = 365–387
|bibcode = 2012Icar..221..365P
|doi = 10.1016/j.icarus.2012.07.026
|access-date= 25 April 2017}}
|first1 = Cristina A. |last1 = Thomas
|first2 = Joshua P. |last2 = Emery
|first3 = David E. |last3 = Trilling
|first4 = Marco |last4 = Delbó
|first5 = Joseph L. |last5 = Hora
|first6 = Michael |last6 = Mueller
|date = January 2014
|title = Physical characterization of Warm Spitzer-observed near-Earth objects
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014Icar..228..217T
|journal = Icarus
|volume = 228
|pages = 217–246
|bibcode = 2014Icar..228..217T
|doi = 10.1016/j.icarus.2013.10.004
|arxiv = 1310.2000
|hdl = 2060/20140012047
|s2cid = 119278697
|access-date= 25 April 2017}}
|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
|s2cid = 53493339 |access-date= 25 April 2017}}
}}
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/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html |date=16 December 2017 }})
- [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
- {{NeoDys|3102}}
- {{ESA-SSA|3102|Krok}}
- {{JPL small body}}
{{Minor planets navigator |3101 Goldberger |number=3102 |3103 Eger}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Krok}}