Astronomy:2324 Janice
| Discovery [1] | |
|---|---|
| Discovered by | E. F. Helin S. J. Bus |
| Discovery site | Palomar Obs. |
| Discovery date | 7 November 1978 |
| Designations | |
| (2324) Janice | |
| Named after | Janice Cline [1] (Supporter at Caltech) |
| 1978 VS4 · 1929 WH 1934 VR · 1949 ME 1961 UP · 1971 OC1 1975 EM2 · 1977 RY4 A911 MC | |
| Minor planet category | main-belt [1][2] · (outer) background [3] · Themis [4][5] |
| Orbital characteristics [2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 83.28 yr (30,418 d) |
| |{{{apsis}}}|helion}} | 3.6382 AU |
| |{{{apsis}}}|helion}} | 2.5282 AU |
| 3.0832 AU | |
| Eccentricity | 0.1800 |
| Orbital period | 5.41 yr (1,977 d) |
| Mean anomaly | 245.72° |
| Mean motion | 0° 10m 55.56s / day |
| Inclination | 0.3995° |
| Longitude of ascending node | 315.66° |
| 305.63° | |
| Physical characteristics | |
| Mean diameter | 23.55 km (calculated)[4] 24.33±6.61 km[6] 24.44±1.22 km[7] 25.76±7.43 km[8] 28.463±0.354 km[9] 28.532±0.238 km[10] 28.9±15.91 km[11] 31.19±15.91 km[12] |
| Rotation period | 23.2±0.1 h[11] |
| Geometric albedo | 0.038±0.004[10] 0.050±0.040[12] 0.06±0.04[6] 0.0601±0.0049[9] 0.07±0.03[8] 0.08 (assumed)[4] 0.093±0.010[7] |
| C (assumed)[4] | |
| Absolute magnitude (H) | 11.30[7] · 11.40[8][9][12] 11.46±0.36[13] · 11.5[2][4] 11.68[6] |
2324 Janice, provisional designation 1978 VS4, is a dark background asteroid from the outer regions of the asteroid belt, approximately 25 kilometers (16 miles) in diameter. It was discovered on 7 November 1978, by American astronomers Eleanor Helin and Schelte Bus at the Palomar Observatory in California.[1] The asteroid was named for Janice Cline at Caltech. The presumably C-type asteroid has a rotation period of 23.2 hours.[4]
Orbit and classification
Based on osculating Keplerian orbital elements, Janice is located in the region of the Themis family (602), a very large family of carbonaceous asteroids, named after 24 Themis.[4]
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),[3] as well as a core member of the Themis family (according to Milani and Knežević).[5]
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.[2] The body's observation arc begins with its first observation as A911 MC at Lowell Observatory in June 1911, more than 67 years prior to its official discovery observation at Palomar.[1]
Physical characteristics
Janice is a presumed carbonaceous C-type asteroid which is the overall spectral type of members of the Themis family (602).[4]
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 (730). Lightcurve analysis gave a tentative rotation period of 23.2 hours with a brightness amplitude of 0.19 magnitude ({{{1}}}).[11] As of 2018, no secure period has been obtained.[4]
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.[6][7][8][9][10][12]
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.[4]
Naming
This minor planet was named after Janice Cline, who for many years has encouraged astrometric studies of minor planets at Caltech.[1] The official naming citation was published by the Minor Planet Center on 1 March 1981 (M.P.C. 5850).[14]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "2324 Janice (1978 VS4)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=2324.
- ↑ 2.0 2.1 2.2 2.3 "JPL Small-Body Database Browser: 2324 Janice (1978 VS4)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2002324.
- ↑ 3.0 3.1 "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. https://sbntools.psi.edu/ferret/PropertySearch/familyForm.action.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 "LCDB Data for (2324) Janice". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=2324%7CJanice.
- ↑ 5.0 5.1 "Asteroid 2324 Janice – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=2324.
- ↑ 6.0 6.1 6.2 6.3 Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T. et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal 152 (3): 12. doi:10.3847/0004-6256/152/3/63. Bibcode: 2016AJ....152...63N.
- ↑ 7.0 7.1 7.2 7.3 Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan 63 (5): 1117–1138. doi:10.1093/pasj/63.5.1117. Bibcode: 2011PASJ...63.1117U. (online, AcuA catalog p. 153)
- ↑ 8.0 8.1 8.2 8.3 Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T. et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal 814 (2): 13. doi:10.1088/0004-637X/814/2/117. Bibcode: 2015ApJ...814..117N.
- ↑ 9.0 9.1 9.2 9.3 Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D. et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal 741 (2): 25. doi:10.1088/0004-637X/741/2/90. Bibcode: 2011ApJ...741...90M.
- ↑ 10.0 10.1 10.2 Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J. et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal 741 (2): 20. doi:10.1088/0004-637X/741/2/68. Bibcode: 2011ApJ...741...68M.
- ↑ 11.0 11.1 11.2 Gartrelle, Gordon M. (April 2012). "Lightcurve Results for Eleven Asteroids". The Minor Planet Bulletin 39 (2): 40–46. ISSN 1052-8091. Bibcode: 2012MPBu...39...40G.
- ↑ 12.0 12.1 12.2 12.3 Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C. et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters 759 (1): 5. doi:10.1088/2041-8205/759/1/L8. Bibcode: 2012ApJ...759L...8M.
- ↑ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus 261: 34–47. doi:10.1016/j.icarus.2015.08.007. Bibcode: 2015Icar..261...34V.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html.
External links
- Asteroid Lightcurve Database (LCDB), query form (info )
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 2324 Janice at AstDyS-2, Asteroids—Dynamic Site
- 2324 Janice at the JPL Small-Body Database
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