2324 Janice
{{Short description|Dark background asteroid from the outer regions of the asteroid belt}}
{{Use dmy dates|date=March 2018}}
{{Infobox planet
| minorplanet = yes
| name = 2324 Janice
| background = #D6D6D6
| image =
| image_size =
| caption =
| discoverer = E. F. Helin
S. J. Bus
| discovery_site = Palomar Obs.
| discovered = 7 November 1978
| mpc_name = (2324) Janice
| alt_names = {{mp|1978 VS|4}}{{·}}1929 WH
1934 VR{{·}}1949 ME
1961 UP{{·}}{{mp|1971 OC|1}}
{{mp|1975 EM|2}}{{·}}{{mp|1977 RY|4}}
A911 MC
| pronounced =
| named_after = Janice Cline
{{small|(Supporter at Caltech)}}
| mp_category = main-belt{{·}}{{small|(outer)}}
{{nowrap|background{{·}}Themis}}
| epoch = 23 March 2018 (JD 2458200.5)
| uncertainty = 0
| observation_arc = 83.28 yr (30,418 d)
| aphelion = 3.6382 AU
| perihelion = 2.5282 AU
| semimajor = 3.0832 AU
| eccentricity = 0.1800
| period = 5.41 yr (1,977 d)
| mean_anomaly = 245.72°
| mean_motion = {{Deg2DMS|0.1821|sup=ms}} / day
| inclination = 0.3995°
| asc_node = 315.66°
| arg_peri = 305.63°
| mean_diameter = {{val|23.55|ul=km}} {{small|(calculated)}}
{{val|24.33|6.61|u=km}}
{{val|24.44|1.22|u=km}}
{{val|25.76|7.43|u=km}}
{{val|28.463|0.354|u=km}}
{{val|28.532|0.238|u=km}}
{{val|28.9|15.91|u=km}}
{{val|31.19|15.91|u=km}}
| rotation = {{val|23.2|0.1|ul=h}}
| albedo = {{val|0.038|0.004}}
{{val|0.050|0.040}}
{{val|0.06|0.04}}
{{val|0.0601|0.0049}}
{{val|0.07|0.03}}
0.08 {{small|(assumed)}}
{{val|0.093|0.010}}
| spectral_type = C {{small|(assumed)}}
| abs_magnitude = 11.30{{·}}11.40
{{val|11.46|0.36}}{{·}}11.5
11.68
}}
2324 Janice, provisional designation {{mp|1978 VS|4}}, is a dark background asteroid from the outer regions of the asteroid belt, approximately {{convert|25|km|mi|abbr=off|sp=us}} in diameter. It was discovered on 7 November 1978, by American astronomers Eleanor Helin and Schelte Bus at the Palomar Observatory in California. The asteroid was named for Janice Cline at Caltech. The presumably C-type asteroid has a rotation period of 23.2 hours.
Orbit and classification
Based on osculating Keplerian orbital elements, Janice is located in the region of the Themis family ({{small|602}}), a very large family of carbonaceous asteroids, named after 24 Themis.
When applying the hierarchical clustering method to its proper orbital elements, the object is both a non-family asteroid of the main belt's background population (according to Nesvorný), as well as a core member of the Themis family (according to Milani and Knežević).
It orbits the Sun in the outer main-belt at a distance of 2.5–3.6 AU once every 5 years and 5 months (1,977 days; semi-major axis of 3.08 AU). Its orbit has an eccentricity of 0.18 and an inclination of 0° with respect to the ecliptic. The body's observation arc begins with its first observation as {{mp|A911 MC}} at Lowell Observatory in June 1911, more than 67 years prior to its official discovery observation at Palomar.
Physical characteristics
Janice is a presumed carbonaceous C-type asteroid which is the overall spectral type of members of the Themis family ({{small|602}}).
= Rotation period =
In October 2010, a rotational lightcurve of Janice was obtained from photometric observations by Gordon Gartrelle at the University of North Dakota Observatory in Grand Forks {{Obscode|730}}. Lightcurve analysis gave a tentative rotation period of 23.2 hours with a brightness amplitude of 0.19 magnitude ({{small|U=2-}}). As of 2018, no secure period has been obtained.
= Diameter and albedo =
According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Janice measures between 24.33 and 31.19 kilometers in diameter and its surface has an albedo between 0.038 and 0.093.
The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a diameter of 23.55 kilometers based on an absolute magnitude of 11.5.
Naming
This minor planet was named after Janice Cline, who for many years has encouraged astrometric studies of minor planets at Caltech. The official naming citation was published by the Minor Planet Center on 1 March 1981 ({{small|M.P.C. 5850}}).
References
{{reflist|30em|refs=
|type = 2018-02-25 last obs.
|title = JPL Small-Body Database Browser: 2324 Janice (1978 VS4)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2002324
|publisher = Jet Propulsion Laboratory
|access-date = 26 March 2018}}
|title = 2324 Janice (1978 VS4)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=2324
|access-date = 26 March 2018}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|access-date = 26 March 2018}}
|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
|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
|s2cid = 118745497 }}
|title = LCDB Data for (2324) Janice
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=2324%7CJanice
|access-date = 26 March 2018}}
|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
|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
|s2cid = 46350317 }}
|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
|s2cid = 35447010 }}
|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
}} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-source=J/PASJ/63/1117/acua_v1&Num=2324 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])
|display-authors = 6
|first1 = C. R. |last1 = Nugent
|first2 = A. |last2 = Mainzer
|first3 = J. |last3 = Bauer
|first4 = R. M. |last4 = Cutri
|first5 = E. A. |last5 = Kramer
|first6 = T. |last6 = Grav
|first7 = J. |last7 = Masiero
|first8 = S. |last8 = Sonnett
|first9 = E. L. |last9 = Wright
|date = September 2016
|title = NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos
|journal = The Astronomical Journal
|volume = 152
|issue = 3
|page = 12
|bibcode = 2016AJ....152...63N
|doi = 10.3847/0004-6256/152/3/63
|arxiv = 1606.08923
|doi-access = free }}
|display-authors = 6
|first1 = C. R. |last1 = Nugent
|first2 = A. |last2 = Mainzer
|first3 = J. |last3 = Masiero
|first4 = J. |last4 = Bauer
|first5 = R. M. |last5 = Cutri
|first6 = T. |last6 = Grav
|first7 = E. |last7 = Kramer
|first8 = S. |last8 = Sonnett
|first9 = R. |last9 = Stevenson
|first10 = E. L. |last10 = Wright
|date = December 2015
|title = NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos
|journal = The Astrophysical Journal
|volume = 814
|issue = 2
|page = 13
|bibcode = 2015ApJ...814..117N
|doi = 10.1088/0004-637X/814/2/117
|arxiv = 1509.02522
|s2cid = 9341381 }}
|author = Gartrelle, Gordon M.
|date = April 2012
|title = Lightcurve Results for Eleven Asteroids
|journal = The Minor Planet Bulletin
|volume = 39
|issue = 2
|pages = 40–46
|issn = 1052-8091
|bibcode = 2012MPBu...39...40G
}}
|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
|journal = Icarus
|volume = 261
|pages = 34–47
|bibcode = 2015Icar..261...34V
|doi = 10.1016/j.icarus.2015.08.007
|arxiv = 1506.00762
|s2cid = 53493339 }}
|title = Small Bodies Data Ferret
|work = Nesvorny HCM Asteroid Families V3.0
|url = https://sbntools.psi.edu/ferret/PropertySearch/familyForm.action
|access-date = 26 March 2018
|archive-url = https://web.archive.org/web/20170802210005/http://sbntools.psi.edu/ferret/PropertySearch/familyForm.action
|archive-date = 2 August 2017
}}
|title = Asteroid 2324 Janice – Proper Elements
|publisher = AstDyS-2, Asteroids – Dynamic Site
|url = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=2324
|access-date= 29 October 2019}}
}}
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
- [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
- {{AstDys|2324}}
- {{JPL small body}}
{{Minor planets navigator |2323 Zverev |number=2324 |2325 Chernykh}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Janice}}
Category:Discoveries by Eleanor F. Helin